feat(marketplace): purchase service with atomic escrow, 30/70 fee splitting and refunds

- POST /api/chat/messages/{message_id}/report for reporting messages with category/reason
- Idempotent duplicate report rejection (409)
- GET /api/moderation/reports for queue listing (restricted to moderators/admins)
- POST /api/moderation/reports/{id}/resolve supporting dismiss, remove, warn, ban actions
- Audit fields (moderator_id, resolved_at, action) recorded on resolution
- Added 9 integration tests in backend/tests/test_chat_reports.py (all passing)

assets/editor/object_catalog.json

@@ -0,0 +1,40 @@
+{
+  "objects": {
+    "crate_small": {
+      "asset_id": "props/crate_small.glb",
+      "type": "prop",
+      "display_name": "Small Crate",
+      "category": "props"
+    },
+    "rock_01": {
+      "asset_id": "props/rock_01.glb",
+      "type": "prop",
+      "display_name": "Rock",
+      "category": "nature"
+    },
+    "tree_pine_01": {
+      "asset_id": "props/tree_pine_01.glb",
+      "type": "prop",
+      "display_name": "Pine Tree",
+      "category": "nature"
+    },
+    "lamp_post_01": {
+      "asset_id": "props/lamp_post_01.glb",
+      "type": "prop",
+      "display_name": "Lamp Post",
+      "category": "props"
+    },
+    "chest_01": {
+      "asset_id": "props/chest.glb",
+      "type": "interactable",
+      "display_name": "Treasure Chest",
+      "category": "interactables"
+    },
+    "spawn_point": {
+      "asset_id": "",
+      "type": "spawn_point",
+      "display_name": "Spawn Point",
+      "category": "gameplay"
+    }
+  }
+}

assets/scripting/behaviors/demo_chest.json

@@ -0,0 +1,17 @@
+{
+  "content_flags": {
+    "violence": "none",
+    "mature": false
+  },
+  "rules": [
+    {
+      "trigger": {"type": "on_interact"},
+      "conditions": [],
+      "actions": [
+        {"verb": "give_item", "item_id": "gold_coin", "count": 3},
+        {"verb": "play_sound", "sound_id": "chest_open"},
+        {"verb": "rotate", "target": "self", "degrees": 90, "axis": "y", "duration": 0.4}
+      ]
+    }
+  ]
+}

assets/scripting/spawn_catalog.json

@@ -0,0 +1,8 @@
+{
+  "templates": {
+    "small_crate": {
+      "asset_id": "props/crate_small.glb",
+      "display_name": "Small Crate"
+    }
+  }
+}

backend/alembic/versions/0006_add_presence_columns.py

@@ -0,0 +1,33 @@
+"""add presence columns to users
+
+Revision ID: 0006_add_presence_columns
+Revises: 0005_add_world_content_tables
+Create Date: 2026-09-14 00:00:00.000000
+
+Ported forward from the orphaned agent/dd2a126b57a1 branch (originally
+2a9b9873244a_add_presence_columns.py, down_revision 0001_initial) and
+rebased onto the current migration head. See app/services/presence.py /
+app/routers/presence.py.
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+# revision identifiers, used by Alembic.
+revision: str = "0006_add_presence_columns"
+down_revision: Union[str, None] = "0005_add_world_content_tables"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    """Add last_seen_at and status_message columns to users table."""
+    op.add_column("users", sa.Column("last_seen_at", sa.DateTime(timezone=True), nullable=True))
+    op.add_column("users", sa.Column("status_message", sa.Text(), nullable=True))
+
+
+def downgrade() -> None:
+    """Remove presence columns from users table."""
+    op.drop_column("users", "status_message")
+    op.drop_column("users", "last_seen_at")

backend/alembic/versions/0007_add_social_graph_tables.py

@@ -0,0 +1,118 @@
+"""add social graph tables (friendships, follows, blocks)
+
+Revision ID: 0007_add_social_graph_tables
+Revises: 0006_add_presence_columns
+Create Date: 2026-09-15 00:00:00.000000
+
+docs/planning/social.md US-1 / app/models/social.py. Models + migration
+only -- the request/accept/block business logic lives in the sibling
+"Friends & follow API router" task.
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.dialects import postgresql
+
+# revision identifiers, used by Alembic.
+revision: str = "0007_add_social_graph_tables"
+down_revision: Union[str, None] = "0006_add_presence_columns"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    friendship_status = postgresql.ENUM(
+        "pending", "accepted", name="friendship_status"
+    )
+    friendship_status.create(op.get_bind(), checkfirst=True)
+
+    op.create_table(
+        "friendships",
+        sa.Column("id", sa.Integer(), primary_key=True),
+        sa.Column(
+            "requester_id",
+            sa.Integer(),
+            sa.ForeignKey("users.id", ondelete="CASCADE"),
+            nullable=False,
+        ),
+        sa.Column(
+            "addressee_id",
+            sa.Integer(),
+            sa.ForeignKey("users.id", ondelete="CASCADE"),
+            nullable=False,
+        ),
+        sa.Column(
+            "status",
+            postgresql.ENUM(
+                "pending", "accepted", name="friendship_status", create_type=False
+            ),
+            nullable=False,
+            server_default="pending",
+        ),
+        sa.Column("created_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
+        sa.Column("updated_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
+        sa.UniqueConstraint("requester_id", "addressee_id", name="uq_friendships_pair"),
+    )
+    op.create_index("ix_friendships_requester_id", "friendships", ["requester_id"])
+    op.create_index("ix_friendships_addressee_id", "friendships", ["addressee_id"])
+
+    op.create_table(
+        "follows",
+        sa.Column("id", sa.Integer(), primary_key=True),
+        sa.Column(
+            "follower_id",
+            sa.Integer(),
+            sa.ForeignKey("users.id", ondelete="CASCADE"),
+            nullable=False,
+        ),
+        sa.Column(
+            "followed_id",
+            sa.Integer(),
+            sa.ForeignKey("users.id", ondelete="CASCADE"),
+            nullable=False,
+        ),
+        sa.Column("created_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
+        sa.Column("updated_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
+        sa.UniqueConstraint("follower_id", "followed_id", name="uq_follows_pair"),
+    )
+    op.create_index("ix_follows_follower_id", "follows", ["follower_id"])
+    op.create_index("ix_follows_followed_id", "follows", ["followed_id"])
+
+    op.create_table(
+        "blocks",
+        sa.Column("id", sa.Integer(), primary_key=True),
+        sa.Column(
+            "blocker_id",
+            sa.Integer(),
+            sa.ForeignKey("users.id", ondelete="CASCADE"),
+            nullable=False,
+        ),
+        sa.Column(
+            "blocked_id",
+            sa.Integer(),
+            sa.ForeignKey("users.id", ondelete="CASCADE"),
+            nullable=False,
+        ),
+        sa.Column("created_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
+        sa.Column("updated_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
+        sa.UniqueConstraint("blocker_id", "blocked_id", name="uq_blocks_pair"),
+    )
+    op.create_index("ix_blocks_blocker_id", "blocks", ["blocker_id"])
+    op.create_index("ix_blocks_blocked_id", "blocks", ["blocked_id"])
+
+
+def downgrade() -> None:
+    op.drop_index("ix_blocks_blocked_id", table_name="blocks")
+    op.drop_index("ix_blocks_blocker_id", table_name="blocks")
+    op.drop_table("blocks")
+
+    op.drop_index("ix_follows_followed_id", table_name="follows")
+    op.drop_index("ix_follows_follower_id", table_name="follows")
+    op.drop_table("follows")
+
+    op.drop_index("ix_friendships_addressee_id", table_name="friendships")
+    op.drop_index("ix_friendships_requester_id", table_name="friendships")
+    op.drop_table("friendships")
+
+    postgresql.ENUM(name="friendship_status").drop(op.get_bind(), checkfirst=True)

backend/alembic/versions/0008_add_chat_tables.py

@@ -0,0 +1,178 @@
+"""add chat tables (conversations, messages, message_reports)
+
+Revision ID: 0008_add_chat_tables
+Revises: 0007_add_social_graph_tables
+Create Date: 2026-09-15 00:00:00.000000
+
+docs/planning/social.md US-4 / app/models/chat.py. Models + migration only
+-- text filtering, rate limiting, and send/report/moderation endpoints live
+in sibling tasks that depend on this one.
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.dialects import postgresql
+
+# revision identifiers, used by Alembic.
+revision: str = "0008_add_chat_tables"
+down_revision: Union[str, None] = "0007_add_social_graph_tables"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    message_report_status = postgresql.ENUM(
+        "open", "resolved", "dismissed", name="message_report_status"
+    )
+    message_report_status.create(op.get_bind(), checkfirst=True)
+
+    op.create_table(
+        "conversations",
+        sa.Column("id", sa.Integer(), primary_key=True),
+        sa.Column(
+            "user_a_id",
+            sa.Integer(),
+            sa.ForeignKey("users.id", ondelete="CASCADE"),
+            nullable=False,
+        ),
+        sa.Column(
+            "user_b_id",
+            sa.Integer(),
+            sa.ForeignKey("users.id", ondelete="CASCADE"),
+            nullable=False,
+        ),
+        sa.Column("created_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
+        sa.Column("updated_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
+        sa.UniqueConstraint("user_a_id", "user_b_id", name="uq_conversations_pair"),
+        sa.CheckConstraint("user_a_id < user_b_id", name="ck_conversations_ordered_pair"),
+    )
+    op.create_index("ix_conversations_user_a_id", "conversations", ["user_a_id"])
+    op.create_index("ix_conversations_user_b_id", "conversations", ["user_b_id"])
+
+    op.create_table(
+        "conversation_participants",
+        sa.Column("id", sa.Integer(), primary_key=True),
+        sa.Column(
+            "conversation_id",
+            sa.Integer(),
+            sa.ForeignKey("conversations.id", ondelete="CASCADE"),
+            nullable=False,
+        ),
+        sa.Column(
+            "user_id",
+            sa.Integer(),
+            sa.ForeignKey("users.id", ondelete="CASCADE"),
+            nullable=False,
+        ),
+        sa.Column("created_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
+        sa.UniqueConstraint(
+            "conversation_id", "user_id", name="uq_conversation_participants_pair"
+        ),
+    )
+    op.create_index(
+        "ix_conversation_participants_conversation_id",
+        "conversation_participants",
+        ["conversation_id"],
+    )
+    op.create_index(
+        "ix_conversation_participants_user_id", "conversation_participants", ["user_id"]
+    )
+
+    op.create_table(
+        "messages",
+        sa.Column("id", sa.Integer(), primary_key=True),
+        sa.Column(
+            "sender_id",
+            sa.Integer(),
+            sa.ForeignKey("users.id", ondelete="SET NULL"),
+            nullable=True,
+        ),
+        sa.Column(
+            "conversation_id",
+            sa.Integer(),
+            sa.ForeignKey("conversations.id", ondelete="CASCADE"),
+            nullable=True,
+        ),
+        sa.Column(
+            "world_id",
+            sa.Integer(),
+            sa.ForeignKey("worlds.id", ondelete="CASCADE"),
+            nullable=True,
+        ),
+        sa.Column(
+            "room_id",
+            sa.Integer(),
+            sa.ForeignKey("world_rooms.id", ondelete="CASCADE"),
+            nullable=True,
+        ),
+        sa.Column("body", sa.Text(), nullable=False),
+        sa.Column("filtered", sa.Boolean(), nullable=False, server_default="false"),
+        sa.Column("created_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
+    )
+    op.create_index("ix_messages_sender_id", "messages", ["sender_id"])
+    op.create_index(
+        "ix_messages_conversation_created", "messages", ["conversation_id", "created_at"]
+    )
+    op.create_index("ix_messages_world_created", "messages", ["world_id", "created_at"])
+
+    op.create_table(
+        "message_reports",
+        sa.Column("id", sa.Integer(), primary_key=True),
+        sa.Column(
+            "message_id",
+            sa.Integer(),
+            sa.ForeignKey("messages.id", ondelete="SET NULL"),
+            nullable=True,
+        ),
+        sa.Column(
+            "reporter_id",
+            sa.Integer(),
+            sa.ForeignKey("users.id", ondelete="SET NULL"),
+            nullable=True,
+        ),
+        sa.Column("reason", sa.Text(), nullable=False),
+        sa.Column(
+            "status",
+            postgresql.ENUM(
+                "open", "resolved", "dismissed", name="message_report_status", create_type=False
+            ),
+            nullable=False,
+            server_default="open",
+        ),
+        sa.Column(
+            "moderator_id",
+            sa.Integer(),
+            sa.ForeignKey("users.id", ondelete="SET NULL"),
+            nullable=True,
+        ),
+        sa.Column("resolved_at", sa.DateTime(timezone=True), nullable=True),
+        sa.Column("created_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
+    )
+    op.create_index("ix_message_reports_message_id", "message_reports", ["message_id"])
+    op.create_index("ix_message_reports_reporter_id", "message_reports", ["reporter_id"])
+    op.create_index("ix_message_reports_moderator_id", "message_reports", ["moderator_id"])
+
+
+def downgrade() -> None:
+    op.drop_index("ix_message_reports_moderator_id", table_name="message_reports")
+    op.drop_index("ix_message_reports_reporter_id", table_name="message_reports")
+    op.drop_index("ix_message_reports_message_id", table_name="message_reports")
+    op.drop_table("message_reports")
+
+    op.drop_index("ix_messages_world_created", table_name="messages")
+    op.drop_index("ix_messages_conversation_created", table_name="messages")
+    op.drop_index("ix_messages_sender_id", table_name="messages")
+    op.drop_table("messages")
+
+    op.drop_index("ix_conversation_participants_user_id", table_name="conversation_participants")
+    op.drop_index(
+        "ix_conversation_participants_conversation_id", table_name="conversation_participants"
+    )
+    op.drop_table("conversation_participants")
+
+    op.drop_index("ix_conversations_user_b_id", table_name="conversations")
+    op.drop_index("ix_conversations_user_a_id", table_name="conversations")
+    op.drop_table("conversations")
+
+    postgresql.ENUM(name="message_report_status").drop(op.get_bind(), checkfirst=True)

backend/alembic/versions/0009_add_group_tables.py

@@ -0,0 +1,80 @@
+"""add group tables (groups, group_members)
+
+Revision ID: 0009_add_group_tables
+Revises: 0008_add_chat_tables
+Create Date: 2026-09-15 00:00:00.000000
+
+docs/planning/social.md US-5 / app/models/groups.py. Models + migration only
+-- create/join/leave, role authorization, and the group page endpoint live
+in a sibling task ("Groups API") that depends on this one.
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.dialects import postgresql
+
+# revision identifiers, used by Alembic.
+revision: str = "0009_add_group_tables"
+down_revision: Union[str, None] = "0008_add_chat_tables"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    group_role = postgresql.ENUM("owner", "admin", "member", name="group_role")
+    group_role.create(op.get_bind(), checkfirst=True)
+
+    op.create_table(
+        "groups",
+        sa.Column("id", sa.Integer(), primary_key=True),
+        sa.Column("name", sa.String(length=100), nullable=False),
+        sa.Column("description", sa.Text(), nullable=True),
+        sa.Column(
+            "owner_id",
+            sa.Integer(),
+            sa.ForeignKey("users.id", ondelete="SET NULL"),
+            nullable=True,
+        ),
+        sa.Column("created_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
+        sa.Column("updated_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
+    )
+    op.create_index("ix_groups_owner_id", "groups", ["owner_id"])
+
+    op.create_table(
+        "group_members",
+        sa.Column("id", sa.Integer(), primary_key=True),
+        sa.Column(
+            "group_id",
+            sa.Integer(),
+            sa.ForeignKey("groups.id", ondelete="CASCADE"),
+            nullable=False,
+        ),
+        sa.Column(
+            "user_id",
+            sa.Integer(),
+            sa.ForeignKey("users.id", ondelete="CASCADE"),
+            nullable=False,
+        ),
+        sa.Column(
+            "role",
+            postgresql.ENUM("owner", "admin", "member", name="group_role", create_type=False),
+            nullable=False,
+            server_default="member",
+        ),
+        sa.Column("joined_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
+        sa.UniqueConstraint("group_id", "user_id", name="uq_group_members_pair"),
+    )
+    op.create_index("ix_group_members_group_id", "group_members", ["group_id"])
+    op.create_index("ix_group_members_user_id", "group_members", ["user_id"])
+
+
+def downgrade() -> None:
+    op.drop_index("ix_group_members_user_id", table_name="group_members")
+    op.drop_index("ix_group_members_group_id", table_name="group_members")
+    op.drop_table("group_members")
+
+    op.drop_index("ix_groups_owner_id", table_name="groups")
+    op.drop_table("groups")
+
+    postgresql.ENUM(name="group_role").drop(op.get_bind(), checkfirst=True)

backend/alembic/versions/0010_add_profile_tables.py

@@ -0,0 +1,65 @@
+"""add profile tables (profiles, profile_favorites)
+
+Revision ID: 0010_add_profile_tables
+Revises: 0009_add_group_tables
+Create Date: 2026-09-15 00:00:00.000000
+
+app/models/profile.py. Models + migration + owner-only /api/profile/me
+endpoints only -- the public profile view endpoint (GET /api/profile/{user_id})
+belongs to a sibling task that depends on this one.
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.dialects import postgresql
+
+# revision identifiers, used by Alembic.
+revision: str = "0010_add_profile_tables"
+down_revision: Union[str, None] = "0009_add_group_tables"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    op.create_table(
+        "profiles",
+        sa.Column("user_id", sa.Integer(), sa.ForeignKey("users.id", ondelete="CASCADE"), primary_key=True),
+        sa.Column(
+            "avatar_asset_id",
+            sa.Integer(),
+            sa.ForeignKey("assets.id", ondelete="SET NULL"),
+            nullable=True,
+        ),
+        sa.Column("bio", sa.Text(), nullable=True),
+        sa.Column("privacy_json", postgresql.JSONB(), nullable=False, server_default="{}"),
+        sa.Column("created_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
+        sa.Column("updated_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
+    )
+    op.create_index("ix_profiles_avatar_asset_id", "profiles", ["avatar_asset_id"])
+
+    op.create_table(
+        "profile_favorites",
+        sa.Column(
+            "user_id",
+            sa.Integer(),
+            sa.ForeignKey("users.id", ondelete="CASCADE"),
+            primary_key=True,
+        ),
+        sa.Column(
+            "world_id",
+            sa.Integer(),
+            sa.ForeignKey("worlds.id", ondelete="CASCADE"),
+            primary_key=True,
+        ),
+        sa.Column("created_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
+    )
+    op.create_index("ix_profile_favorites_world_id", "profile_favorites", ["world_id"])
+
+
+def downgrade() -> None:
+    op.drop_index("ix_profile_favorites_world_id", table_name="profile_favorites")
+    op.drop_table("profile_favorites")
+
+    op.drop_index("ix_profiles_avatar_asset_id", table_name="profiles")
+    op.drop_table("profiles")

backend/alembic/versions/0011_add_dm_last_read.py

@@ -0,0 +1,36 @@
+"""add last_read_at to conversation_participants (DM unread tracking)
+
+Revision ID: 0011_add_dm_last_read
+Revises: 0010_add_profile_tables
+Create Date: 2026-09-15 00:00:00.000000
+
+app/routers/chat_dm.py (DM send/list/conversations endpoints). Unread-count
+tracking is implemented as a last-read timestamp per participant: whenever a
+user fetches a conversation's message history, their
+``conversation_participants`` row's ``last_read_at`` is bumped to "now", and
+the conversation-list endpoint counts messages with
+``created_at > last_read_at`` (or all messages if never read) as unread for
+that participant. Nullable/no default so existing rows (none yet in
+practice, but consistent with "never read") read as "everything unread".
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+# revision identifiers, used by Alembic.
+revision: str = "0011_add_dm_last_read"
+down_revision: Union[str, None] = "0010_add_profile_tables"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    op.add_column(
+        "conversation_participants",
+        sa.Column("last_read_at", sa.DateTime(timezone=True), nullable=True),
+    )
+
+
+def downgrade() -> None:
+    op.drop_column("conversation_participants", "last_read_at")

backend/alembic/versions/0012_add_wallet_and_transactions.py

@@ -0,0 +1,90 @@
+"""add wallets and transactions ledger tables
+
+Revision ID: 0012_add_wallet_and_transactions
+Revises: 0011_add_dm_last_read
+Create Date: 2026-09-15 00:00:00.000000
+
+docs/planning/economy.md US-1 (task 8343bc0a730f).
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.dialects import postgresql
+
+# revision identifiers, used by Alembic.
+revision: str = "0012_add_wallet_and_transactions"
+down_revision: Union[str, None] = "0011_add_dm_last_read"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+TRANSACTION_TYPES = (
+    "credit_purchase",
+    "marketplace_purchase",
+    "marketplace_sale",
+    "escrow_release",
+    "payout",
+    "refund",
+    "admin_adjustment",
+)
+
+
+def upgrade() -> None:
+    # 1. Create transaction_type enum for Postgres
+    bind = op.get_bind()
+    if bind.dialect.name == "postgresql":
+        tx_type_enum = postgresql.ENUM(*TRANSACTION_TYPES, name="transaction_type", create_type=False)
+        tx_type_enum.create(bind, checkfirst=True)
+        tx_type_col = postgresql.ENUM(*TRANSACTION_TYPES, name="transaction_type", create_type=False)
+    else:
+        tx_type_col = sa.Enum(*TRANSACTION_TYPES, name="transaction_type")
+
+    # 2. Create wallets table
+    op.create_table(
+        "wallets",
+        sa.Column("id", sa.BigInteger(), autoincrement=True, nullable=False),
+        sa.Column("user_id", sa.Integer(), nullable=False),
+        sa.Column("balance", sa.BigInteger(), server_default="0", nullable=False),
+        sa.Column("created_at", sa.DateTime(timezone=True), server_default=sa.text("now()"), nullable=False),
+        sa.Column("updated_at", sa.DateTime(timezone=True), server_default=sa.text("now()"), nullable=False),
+        sa.CheckConstraint("balance >= 0", name="check_wallet_balance_non_negative"),
+        sa.ForeignKeyConstraint(["user_id"], ["users.id"], ondelete="CASCADE"),
+        sa.PrimaryKeyConstraint("id"),
+        sa.UniqueConstraint("user_id", name="uq_wallets_user_id"),
+    )
+    op.create_index(op.f("ix_wallets_user_id"), "wallets", ["user_id"], unique=True)
+
+    # 3. Create transactions table
+    op.create_table(
+        "transactions",
+        sa.Column("id", sa.BigInteger(), autoincrement=True, nullable=False),
+        sa.Column("wallet_id", sa.BigInteger(), nullable=False),
+        sa.Column("type", tx_type_col, nullable=False),
+        sa.Column("amount", sa.BigInteger(), nullable=False),
+        sa.Column("balance_after", sa.BigInteger(), nullable=False),
+        sa.Column("reference_type", sa.String(), nullable=True),
+        sa.Column("reference_id", sa.String(), nullable=True),
+        sa.Column("idempotency_key", sa.String(), nullable=True),
+        sa.Column("metadata_json", postgresql.JSONB(astext_type=sa.Text()) if bind.dialect.name == "postgresql" else sa.JSON(), nullable=True),
+        sa.Column("created_at", sa.DateTime(timezone=True), server_default=sa.text("now()"), nullable=False),
+        sa.ForeignKeyConstraint(["wallet_id"], ["wallets.id"], ondelete="CASCADE"),
+        sa.PrimaryKeyConstraint("id"),
+        sa.UniqueConstraint("idempotency_key", name="uq_transactions_idempotency_key"),
+    )
+    op.create_index(op.f("ix_transactions_wallet_id"), "transactions", ["wallet_id"], unique=False)
+    op.create_index(op.f("ix_transactions_idempotency_key"), "transactions", ["idempotency_key"], unique=True)
+    op.create_index(op.f("ix_transactions_created_at"), "transactions", ["created_at"], unique=False)
+
+
+def downgrade() -> None:
+    op.drop_index(op.f("ix_transactions_created_at"), table_name="transactions")
+    op.drop_index(op.f("ix_transactions_idempotency_key"), table_name="transactions")
+    op.drop_index(op.f("ix_transactions_wallet_id"), table_name="transactions")
+    op.drop_table("transactions")
+
+    op.drop_index(op.f("ix_wallets_user_id"), table_name="wallets")
+    op.drop_table("wallets")
+
+    bind = op.get_bind()
+    if bind.dialect.name == "postgresql":
+        sa.Enum(*TRANSACTION_TYPES, name="transaction_type").drop(bind, checkfirst=True)

backend/alembic/versions/0013_add_marketplace_tables.py

@@ -0,0 +1,146 @@
+"""add marketplace tables: catalog_items, marketplace_listings, purchases, creator_balances
+
+Revision ID: 0013_add_marketplace_tables
+Revises: 0012_add_wallet_and_transactions
+Create Date: 2026-09-15 00:00:00.000000
+
+docs/planning/economy.md US-3, US-4 (task 166836d55365).
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.dialects import postgresql
+
+# revision identifiers, used by Alembic.
+revision: str = "0013_add_marketplace_tables"
+down_revision: Union[str, None] = "0012_add_wallet_and_transactions"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+ITEM_TYPES = ("asset", "avatar_item", "experience_pass")
+LISTING_STATUSES = ("active", "sold", "delisted", "removed_by_moderation")
+PURCHASE_STATUSES = ("pending_escrow", "completed", "refunded", "reversed")
+
+
+def upgrade() -> None:
+    bind = op.get_bind()
+    is_pg = bind.dialect.name == "postgresql"
+
+    # Enums
+    if is_pg:
+        item_type_enum = postgresql.ENUM(*ITEM_TYPES, name="catalog_item_type", create_type=False)
+        item_type_enum.create(bind, checkfirst=True)
+        item_type_col = postgresql.ENUM(*ITEM_TYPES, name="catalog_item_type", create_type=False)
+
+        listing_status_enum = postgresql.ENUM(*LISTING_STATUSES, name="marketplace_listing_status", create_type=False)
+        listing_status_enum.create(bind, checkfirst=True)
+        listing_status_col = postgresql.ENUM(*LISTING_STATUSES, name="marketplace_listing_status", create_type=False)
+
+        purchase_status_enum = postgresql.ENUM(*PURCHASE_STATUSES, name="purchase_status", create_type=False)
+        purchase_status_enum.create(bind, checkfirst=True)
+        purchase_status_col = postgresql.ENUM(*PURCHASE_STATUSES, name="purchase_status", create_type=False)
+    else:
+        item_type_col = sa.Enum(*ITEM_TYPES, name="catalog_item_type")
+        listing_status_col = sa.Enum(*LISTING_STATUSES, name="marketplace_listing_status")
+        purchase_status_col = sa.Enum(*PURCHASE_STATUSES, name="purchase_status")
+
+    # 1. catalog_items
+    op.create_table(
+        "catalog_items",
+        sa.Column("id", sa.BigInteger(), autoincrement=True, nullable=False),
+        sa.Column("owner_id", sa.Integer(), nullable=False),
+        sa.Column("asset_id", sa.Integer(), nullable=True),
+        sa.Column("item_type", item_type_col, nullable=False),
+        sa.Column("name", sa.String(length=100), nullable=False),
+        sa.Column("description", sa.String(length=2000), nullable=True),
+        sa.Column("metadata_json", postgresql.JSONB(astext_type=sa.Text()) if is_pg else sa.JSON(), nullable=True),
+        sa.Column("created_at", sa.DateTime(timezone=True), server_default=sa.text("now()"), nullable=False),
+        sa.ForeignKeyConstraint(["owner_id"], ["users.id"], ondelete="CASCADE"),
+        sa.ForeignKeyConstraint(["asset_id"], ["assets.id"], ondelete="SET NULL"),
+        sa.PrimaryKeyConstraint("id"),
+    )
+    op.create_index(op.f("ix_catalog_items_owner_id"), "catalog_items", ["owner_id"], unique=False)
+    op.create_index(op.f("ix_catalog_items_asset_id"), "catalog_items", ["asset_id"], unique=False)
+
+    # 2. marketplace_listings
+    op.create_table(
+        "marketplace_listings",
+        sa.Column("id", sa.BigInteger(), autoincrement=True, nullable=False),
+        sa.Column("catalog_item_id", sa.BigInteger(), nullable=False),
+        sa.Column("seller_id", sa.Integer(), nullable=False),
+        sa.Column("price", sa.BigInteger(), nullable=False),
+        sa.Column("status", listing_status_col, server_default="active", nullable=False),
+        sa.Column("created_at", sa.DateTime(timezone=True), server_default=sa.text("now()"), nullable=False),
+        sa.Column("updated_at", sa.DateTime(timezone=True), server_default=sa.text("now()"), nullable=False),
+        sa.CheckConstraint("price > 0", name="check_listing_price_positive"),
+        sa.ForeignKeyConstraint(["catalog_item_id"], ["catalog_items.id"], ondelete="CASCADE"),
+        sa.ForeignKeyConstraint(["seller_id"], ["users.id"], ondelete="CASCADE"),
+        sa.PrimaryKeyConstraint("id"),
+    )
+    op.create_index(op.f("ix_marketplace_listings_catalog_item_id"), "marketplace_listings", ["catalog_item_id"], unique=False)
+    op.create_index(op.f("ix_marketplace_listings_seller_id"), "marketplace_listings", ["seller_id"], unique=False)
+
+    # 3. purchases
+    op.create_table(
+        "purchases",
+        sa.Column("id", sa.BigInteger(), autoincrement=True, nullable=False),
+        sa.Column("listing_id", sa.BigInteger(), nullable=True),
+        sa.Column("buyer_id", sa.Integer(), nullable=False),
+        sa.Column("seller_id", sa.Integer(), nullable=False),
+        sa.Column("price", sa.BigInteger(), nullable=False),
+        sa.Column("platform_fee", sa.BigInteger(), nullable=False),
+        sa.Column("seller_net", sa.BigInteger(), nullable=False),
+        sa.Column("status", purchase_status_col, server_default="pending_escrow", nullable=False),
+        sa.Column("escrow_hold_until", sa.DateTime(timezone=True), nullable=True),
+        sa.Column("created_at", sa.DateTime(timezone=True), server_default=sa.text("now()"), nullable=False),
+        sa.ForeignKeyConstraint(["listing_id"], ["marketplace_listings.id"], ondelete="SET NULL"),
+        sa.ForeignKeyConstraint(["buyer_id"], ["users.id"], ondelete="CASCADE"),
+        sa.ForeignKeyConstraint(["seller_id"], ["users.id"], ondelete="CASCADE"),
+        sa.PrimaryKeyConstraint("id"),
+    )
+    op.create_index(op.f("ix_purchases_listing_id"), "purchases", ["listing_id"], unique=False)
+    op.create_index(op.f("ix_purchases_buyer_id"), "purchases", ["buyer_id"], unique=False)
+    op.create_index(op.f("ix_purchases_seller_id"), "purchases", ["seller_id"], unique=False)
+
+    # 4. creator_balances
+    op.create_table(
+        "creator_balances",
+        sa.Column("id", sa.BigInteger(), autoincrement=True, nullable=False),
+        sa.Column("user_id", sa.Integer(), nullable=False),
+        sa.Column("available", sa.BigInteger(), server_default="0", nullable=False),
+        sa.Column("pending", sa.BigInteger(), server_default="0", nullable=False),
+        sa.Column("lifetime_earned", sa.BigInteger(), server_default="0", nullable=False),
+        sa.Column("updated_at", sa.DateTime(timezone=True), server_default=sa.text("now()"), nullable=False),
+        sa.CheckConstraint("available >= 0", name="check_creator_available_non_negative"),
+        sa.CheckConstraint("pending >= 0", name="check_creator_pending_non_negative"),
+        sa.CheckConstraint("lifetime_earned >= 0", name="check_creator_lifetime_non_negative"),
+        sa.ForeignKeyConstraint(["user_id"], ["users.id"], ondelete="CASCADE"),
+        sa.PrimaryKeyConstraint("id"),
+        sa.UniqueConstraint("user_id", name="uq_creator_balances_user_id"),
+    )
+    op.create_index(op.f("ix_creator_balances_user_id"), "creator_balances", ["user_id"], unique=True)
+
+
+def downgrade() -> None:
+    op.drop_index(op.f("ix_creator_balances_user_id"), table_name="creator_balances")
+    op.drop_table("creator_balances")
+
+    op.drop_index(op.f("ix_purchases_seller_id"), table_name="purchases")
+    op.drop_index(op.f("ix_purchases_buyer_id"), table_name="purchases")
+    op.drop_index(op.f("ix_purchases_listing_id"), table_name="purchases")
+    op.drop_table("purchases")
+
+    op.drop_index(op.f("ix_marketplace_listings_seller_id"), table_name="marketplace_listings")
+    op.drop_index(op.f("ix_marketplace_listings_catalog_item_id"), table_name="marketplace_listings")
+    op.drop_table("marketplace_listings")
+
+    op.drop_index(op.f("ix_catalog_items_asset_id"), table_name="catalog_items")
+    op.drop_index(op.f("ix_catalog_items_owner_id"), table_name="catalog_items")
+    op.drop_table("catalog_items")
+
+    bind = op.get_bind()
+    if bind.dialect.name == "postgresql":
+        sa.Enum(*PURCHASE_STATUSES, name="purchase_status").drop(bind, checkfirst=True)
+        sa.Enum(*LISTING_STATUSES, name="marketplace_listing_status").drop(bind, checkfirst=True)
+        sa.Enum(*ITEM_TYPES, name="catalog_item_type").drop(bind, checkfirst=True)

backend/app/dependencies.py

@@ -53,3 +53,33 @@ async def get_current_user(
 
 
 CurrentUser = Annotated[User, Depends(get_current_user)]
+
+oauth2_scheme_optional = OAuth2PasswordBearer(tokenUrl="/api/auth/login", auto_error=False)
+
+
+async def get_optional_user(
+    token: Annotated[str | None, Depends(oauth2_scheme_optional)],
+    db: Annotated[AsyncSession, Depends(get_db)],
+) -> User | None:
+    """Resolve the JWT bearer token to a User if present and valid, otherwise None."""
+    if not token:
+        return None
+    try:
+        payload = jwt.decode(
+            token, settings.public_pem, algorithms=[settings.ALGORITHM]
+        )
+        user_id: str | None = payload.get("sub")
+        if user_id is None:
+            return None
+        user_id_int = int(user_id)
+    except (JWTError, ValueError, TypeError):
+        return None
+
+    result = await db.execute(select(User).where(User.id == user_id_int))
+    user = result.scalar_one_or_none()
+    if user is None or not user.is_active:
+        return None
+    return user
+
+
+OptionalUser = Annotated[User | None, Depends(get_optional_user)]

backend/app/gateway/__init__.py

@@ -0,0 +1 @@
+"""WebSocket real-time gateway package."""

backend/app/gateway/ws.py

@@ -0,0 +1,538 @@
+"""Real-time WebSocket gateway.
+
+Multiplexes presence, DM, and world-chat delivery over a single WebSocket
+endpoint (docs/planning/social.md US-2, US-4).
+
+Key features:
+- Authentication via JWT token (query param or initial auth frame).
+- Scoped subscriptions to DM conversations and world channels.
+- Server-derived presence heartbeat (Redis TTL refreshed periodically).
+- Broadcast presence changes (online/offline) to mutual friends.
+- Fan-out via Redis pub/sub.
+- Thread-safe & event-loop-safe dispatch for multi-instance and test environments.
+- Graceful reconnect without duplicate delivery or orphaned state.
+"""
+
+from __future__ import annotations
+
+import asyncio
+from contextlib import asynccontextmanager
+from datetime import datetime, timezone
+import json
+import logging
+from typing import Any
+
+from fastapi import APIRouter, WebSocket, WebSocketDisconnect, status
+from jose import JWTError, jwt
+from sqlalchemy import or_, select
+from sqlalchemy.ext.asyncio import AsyncSession
+import redis.asyncio as aioredis
+
+from app.config import settings
+from app.database import async_session_factory, get_db
+from app.models.chat import ConversationParticipant
+from app.models.social import Friendship, FriendshipStatus
+from app.models.user import User
+from app.models.world import World, WorldVisibility
+from app.services.presence import presence_store
+
+logger = logging.getLogger(__name__)
+
+router = APIRouter()
+
+
+@asynccontextmanager
+async def get_db_session():
+    """Helper to acquire an async DB session respecting test overrides if present."""
+    from app.main import app
+
+    override = app.dependency_overrides.get(get_db)
+    if override:
+        res = override()
+        if hasattr(res, "__anext__"):
+            session = await res.__anext__()
+            try:
+                yield session
+            finally:
+                try:
+                    await res.__anext__()
+                except (StopAsyncIteration, Exception):
+                    pass
+            return
+        elif hasattr(res, "__next__"):
+            session = next(res)
+            try:
+                yield session
+            finally:
+                try:
+                    next(res)
+                except (StopIteration, Exception):
+                    pass
+            return
+
+    async with async_session_factory() as session:
+        yield session
+
+
+async def authenticate_token(token: str) -> User | None:
+    """Validate JWT token and return authenticated User, or None."""
+    try:
+        payload = jwt.decode(token, settings.public_pem, algorithms=[settings.ALGORITHM])
+        user_id_raw = payload.get("sub")
+        if user_id_raw is None:
+            return None
+        user_id = int(user_id_raw)
+    except (JWTError, ValueError, TypeError):
+        return None
+
+    async with get_db_session() as db:
+        res = await db.execute(select(User).where(User.id == user_id))
+        user = res.scalar_one_or_none()
+        if user and user.is_active:
+            return user
+    return None
+
+
+async def get_friend_ids(user_id: int) -> set[int]:
+    """Return set of accepted friend user IDs for user_id."""
+    try:
+        async with get_db_session() as db:
+            res = await db.execute(
+                select(Friendship).where(
+                    or_(Friendship.requester_id == user_id, Friendship.addressee_id == user_id),
+                    Friendship.status == FriendshipStatus.ACCEPTED,
+                )
+            )
+            friendships = res.scalars().all()
+            return {
+                f.addressee_id if f.requester_id == user_id else f.requester_id
+                for f in friendships
+            }
+    except Exception as exc:
+        logger.error("Failed to get friend IDs for user %s: %s", user_id, exc, exc_info=True)
+        return set()
+
+
+async def check_world_access(world_id: int, user_id: int) -> bool:
+    """Verify if user has permission to join/view a world."""
+    async with get_db_session() as db:
+        res = await db.execute(select(World).where(World.id == world_id))
+        world = res.scalar_one_or_none()
+        if not world:
+            return False
+        if world.visibility == WorldVisibility.PUBLIC:
+            return True
+        if world.owner_id == user_id:
+            return True
+        if world.visibility == WorldVisibility.FRIENDS_ONLY:
+            res_fr = await db.execute(
+                select(Friendship.id).where(
+                    or_(
+                        and_(Friendship.requester_id == world.owner_id, Friendship.addressee_id == user_id),
+                        and_(Friendship.requester_id == user_id, Friendship.addressee_id == world.owner_id),
+                    ),
+                    Friendship.status == FriendshipStatus.ACCEPTED,
+                ).limit(1)
+            )
+            return res_fr.scalar_one_or_none() is not None
+        return False
+
+
+async def check_conversation_access(conversation_id: int, user_id: int) -> bool:
+    """Verify if user is a participant in the given conversation."""
+    async with get_db_session() as db:
+        res = await db.execute(
+            select(ConversationParticipant.id).where(
+                ConversationParticipant.conversation_id == conversation_id,
+                ConversationParticipant.user_id == user_id,
+            ).limit(1)
+        )
+        return res.scalar_one_or_none() is not None
+
+
+async def _async_update_last_seen(user_id: int, now: datetime):
+    try:
+        async with async_session_factory() as session:
+            res = await session.execute(select(User).where(User.id == user_id))
+            db_user = res.scalar_one_or_none()
+            if db_user:
+                db_user.last_seen_at = now
+                await session.commit()
+    except Exception:
+        pass
+
+
+class ConnectionManager:
+    """Manages active WebSocket connections, subscriptions, presence, and fan-out."""
+
+    def __init__(self):
+        # ws -> User
+        self._connections: dict[WebSocket, User] = {}
+        # ws -> event loop id
+        self._ws_loops: dict[WebSocket, int] = {}
+        # user_id -> set of active WebSockets
+        self._user_connections: dict[int, set[WebSocket]] = {}
+        # user_id -> cached friend user IDs
+        self._user_friend_ids: dict[int, set[int]] = {}
+        # world_id -> set of WebSockets
+        self._world_subs: dict[int, set[WebSocket]] = {}
+        # conversation_id -> set of WebSockets
+        self._dm_subs: dict[int, set[WebSocket]] = {}
+        # ws -> asyncio heartbeat task
+        self._heartbeat_tasks: dict[WebSocket, asyncio.Task] = {}
+        # Per-event-loop Redis pub/sub listener tasks and events
+        self._redis_tasks: dict[int, asyncio.Task] = {}
+        self._subscribed_events: dict[int, asyncio.Event] = {}
+
+    async def ensure_redis_listener(self):
+        """Ensure background Redis pub/sub listener is connected and subscribed for current loop."""
+        loop = asyncio.get_running_loop()
+        loop_key = id(loop)
+        task = self._redis_tasks.get(loop_key)
+        if task is None or task.done():
+            event = asyncio.Event()
+            self._subscribed_events[loop_key] = event
+            task = asyncio.create_task(self._redis_listener(loop_key, event))
+            self._redis_tasks[loop_key] = task
+        else:
+            event = self._subscribed_events.get(loop_key)
+
+        if event:
+            try:
+                await asyncio.wait_for(event.wait(), timeout=2.0)
+            except asyncio.TimeoutError:
+                pass
+
+    async def connect(self, websocket: WebSocket, user: User):
+        """Register an authenticated connection."""
+        await self.ensure_redis_listener()
+        loop_key = id(asyncio.get_running_loop())
+
+        self._connections[websocket] = user
+        self._ws_loops[websocket] = loop_key
+        self._user_connections.setdefault(user.id, set()).add(websocket)
+
+        # Cache friend IDs for instant presence dispatch
+        friend_ids = await get_friend_ids(user.id)
+        self._user_friend_ids[user.id] = friend_ids
+
+        # Mark user online in Redis and DB
+        await presence_store.heartbeat(user.id)
+        now = datetime.now(timezone.utc)
+        asyncio.create_task(_async_update_last_seen(user.id, now))
+
+        # Start periodic heartbeat task (every 20 seconds)
+        self._heartbeat_tasks[websocket] = asyncio.create_task(
+            self._run_periodic_heartbeat(user.id)
+        )
+
+        # Broadcast online presence to friends via Redis
+        await self.broadcast_presence(user.id, user.username, is_online=True, friend_ids=friend_ids)
+
+    async def disconnect(self, websocket: WebSocket):
+        """Unregister a connection and clean up subscriptions and presence."""
+        user = self._connections.pop(websocket, None)
+        self._ws_loops.pop(websocket, None)
+        task = self._heartbeat_tasks.pop(websocket, None)
+        if task:
+            task.cancel()
+
+        # Clean subscriptions
+        for world_id in list(self._world_subs.keys()):
+            self._world_subs[world_id].discard(websocket)
+            if not self._world_subs[world_id]:
+                self._world_subs.pop(world_id, None)
+
+        for conv_id in list(self._dm_subs.keys()):
+            self._dm_subs[conv_id].discard(websocket)
+            if not self._dm_subs[conv_id]:
+                self._dm_subs.pop(conv_id, None)
+
+        if user is None:
+            return
+
+        user_id = user.id
+        username = user.username
+        user_set = self._user_connections.get(user_id)
+        if user_set:
+            user_set.discard(websocket)
+            if not user_set:
+                self._user_connections.pop(user_id, None)
+
+        # If user has no more open connections, mark offline immediately
+        if user_id not in self._user_connections:
+            await presence_store.clear_heartbeat(user_id)
+            now = datetime.now(timezone.utc)
+            asyncio.create_task(_async_update_last_seen(user_id, now))
+            friend_ids = self._user_friend_ids.pop(user_id, set())
+            await self.broadcast_presence(
+                user_id, username, is_online=False, last_seen_at=now, friend_ids=friend_ids
+            )
+
+    async def _run_periodic_heartbeat(self, user_id: int):
+        """Keep Redis TTL alive while connection is open."""
+        try:
+            while True:
+                await asyncio.sleep(20)
+                await presence_store.heartbeat(user_id)
+        except asyncio.CancelledError:
+            pass
+
+    async def subscribe_world(self, websocket: WebSocket, world_id: int) -> bool:
+        user = self._connections.get(websocket)
+        if not user:
+            return False
+        allowed = await check_world_access(world_id, user.id)
+        if not allowed:
+            return False
+        self._world_subs.setdefault(world_id, set()).add(websocket)
+        return True
+
+    def unsubscribe_world(self, websocket: WebSocket, world_id: int):
+        if world_id in self._world_subs:
+            self._world_subs[world_id].discard(websocket)
+
+    async def subscribe_dm(self, websocket: WebSocket, conversation_id: int) -> bool:
+        user = self._connections.get(websocket)
+        if not user:
+            return False
+        allowed = await check_conversation_access(conversation_id, user.id)
+        if not allowed:
+            return False
+        self._dm_subs.setdefault(conversation_id, set()).add(websocket)
+        return True
+
+    def unsubscribe_dm(self, websocket: WebSocket, conversation_id: int):
+        if conversation_id in self._dm_subs:
+            self._dm_subs[conversation_id].discard(websocket)
+
+    async def send_to_ws(self, websocket: WebSocket, message: dict):
+        """Deliver frame to websocket if it belongs to current event loop."""
+        cur_loop = id(asyncio.get_running_loop())
+        if self._ws_loops.get(websocket) != cur_loop:
+            return
+        try:
+            await websocket.send_text(json.dumps(message, default=str))
+        except Exception:
+            pass
+
+    async def broadcast_world_chat(
+        self, world_id: int, message_payload: dict, room_id: int | None = None
+    ):
+        """Send world chat message to all connected clients on this loop subscribed to world_id."""
+        targets = list(self._world_subs.get(world_id, set()))
+        if not targets:
+            return
+        frame = {
+            "type": "world_chat",
+            "world_id": world_id,
+            "room_id": room_id,
+            "message": message_payload,
+        }
+        for ws in targets:
+            await self.send_to_ws(ws, frame)
+
+    async def broadcast_dm_chat(self, conversation_id: int, message_payload: dict):
+        """Send DM message to all connected clients on this loop subscribed to conversation_id."""
+        targets = list(self._dm_subs.get(conversation_id, set()))
+        frame = {
+            "type": "dm_chat",
+            "conversation_id": conversation_id,
+            "message": message_payload,
+        }
+        for ws in targets:
+            await self.send_to_ws(ws, frame)
+
+    async def broadcast_presence(
+        self,
+        user_id: int,
+        username: str,
+        is_online: bool,
+        last_seen_at: datetime | None = None,
+        friend_ids: set[int] | None = None,
+    ):
+        """Broadcast presence update to mutual friends via Redis."""
+        if friend_ids is None:
+            friend_ids = await get_friend_ids(user_id)
+        if not friend_ids:
+            return
+
+        frame = {
+            "type": "presence",
+            "user_id": user_id,
+            "username": username,
+            "is_online": is_online,
+            "last_seen_at": last_seen_at.isoformat() if last_seen_at else None,
+            "friend_ids": list(friend_ids),
+        }
+
+        # Redis broadcast for all loops/instances
+        try:
+            client = aioredis.from_url(settings.REDIS_URL, encoding="utf-8", decode_responses=True)
+            async with client:
+                await client.publish("presence:events", json.dumps(frame, default=str))
+        except Exception as exc:
+            logger.error("Failed to publish presence to Redis: %s", exc, exc_info=True)
+
+    async def _redis_listener(self, loop_key: int, event: asyncio.Event):
+        """Listen to Redis pub/sub channels for cross-instance message dispatch."""
+        while True:
+            try:
+                client = aioredis.from_url(settings.REDIS_URL, encoding="utf-8", decode_responses=True)
+                pubsub = client.pubsub()
+                await pubsub.psubscribe("world:*:chat", "dm:*:chat", "presence:events")
+                event.set()
+                logger.info("Gateway Redis pub/sub listener active for loop %s", loop_key)
+                async for message in pubsub.listen():
+                    if message["type"] != "pmessage":
+                        continue
+                    channel = message["channel"]
+                    raw_data = message["data"]
+                    try:
+                        data = json.loads(raw_data)
+                    except Exception:
+                        continue
+
+                    if channel.startswith("world:") and channel.endswith(":chat"):
+                        parts = channel.split(":")
+                        world_id = int(parts[1])
+                        await self.broadcast_world_chat(world_id, data, room_id=data.get("room_id"))
+                    elif channel.startswith("dm:") and channel.endswith(":chat"):
+                        parts = channel.split(":")
+                        conv_id = int(parts[1])
+                        await self.broadcast_dm_chat(conv_id, data)
+                    elif channel == "presence:events":
+                        logger.info("Redis presence event received: %s. Active users: %s", data, list(self._user_connections.keys()))
+                        for friend_id in data.get("friend_ids", []):
+                            targets = list(self._user_connections.get(friend_id, set()))
+                            logger.info("Friend %s has %s targets", friend_id, len(targets))
+                            for ws in targets:
+                                await self.send_to_ws(ws, data)
+            except asyncio.CancelledError:
+                break
+            except Exception as exc:
+                logger.debug("Redis listener encountered error, retrying in 2s: %s", exc)
+                event.clear()
+                await asyncio.sleep(2)
+
+
+connection_manager = ConnectionManager()
+
+
+# ──────────────────────────────── WebSocket Route ────────────────────────────
+
+
+@router.websocket("/ws")
+async def websocket_gateway(websocket: WebSocket, token: str | None = None):
+    """Main WebSocket gateway endpoint for real-time presence and chat."""
+    user: User | None = None
+    # 1. Check query parameter token
+    if token:
+        user = await authenticate_token(token)
+        if user is None:
+            await websocket.close(code=status.WS_1008_POLICY_VIOLATION)
+            return
+
+    await websocket.accept()
+
+    # 2. If not authenticated via query param, wait for first auth frame
+    if user is None:
+        try:
+            raw = await asyncio.wait_for(websocket.receive_text(), timeout=3.0)
+            data = json.loads(raw)
+            if data.get("type") == "auth" and data.get("token"):
+                user = await authenticate_token(data["token"])
+        except (asyncio.TimeoutError, json.JSONDecodeError, WebSocketDisconnect):
+            pass
+
+        if user is None:
+            try:
+                await websocket.send_text(json.dumps({"type": "error", "message": "Authentication failed"}))
+                await websocket.close(code=status.WS_1008_POLICY_VIOLATION)
+            except Exception:
+                pass
+            return
+
+    # Mark user online in Redis immediately upon successful auth
+    await presence_store.heartbeat(user.id)
+
+    # Send auth_ok handshake immediately upon successful authentication
+    await websocket.send_text(
+        json.dumps({
+            "type": "auth_ok",
+            "user_id": user.id,
+            "username": user.username,
+        })
+    )
+
+    # Register with connection manager for presence and real-time event delivery
+    await connection_manager.connect(websocket, user)
+
+    try:
+        while True:
+            text = await websocket.receive_text()
+            try:
+                msg = json.loads(text)
+            except json.JSONDecodeError:
+                await websocket.send_text(json.dumps({"type": "error", "message": "Invalid JSON"}))
+                continue
+
+            msg_type = msg.get("type")
+            if msg_type == "ping":
+                await websocket.send_text(json.dumps({"type": "pong"}))
+            elif msg_type == "heartbeat":
+                await presence_store.heartbeat(user.id)
+                await websocket.send_text(json.dumps({"type": "heartbeat_ack"}))
+            elif msg_type in ("subscribe_world", "subscribe") and (
+                msg.get("world_id") or msg.get("channel") == "world"
+            ):
+                world_id = msg.get("world_id") or msg.get("id")
+                if isinstance(world_id, int):
+                    ok = await connection_manager.subscribe_world(websocket, world_id)
+                    if ok:
+                        await websocket.send_text(
+                            json.dumps({"type": "subscribed", "channel": "world", "id": world_id})
+                        )
+                    else:
+                        await websocket.send_text(
+                            json.dumps({"type": "error", "message": f"Cannot subscribe to world {world_id}"})
+                        )
+            elif msg_type in ("unsubscribe_world", "unsubscribe") and (
+                msg.get("world_id") or msg.get("channel") == "world"
+            ):
+                world_id = msg.get("world_id") or msg.get("id")
+                if isinstance(world_id, int):
+                    connection_manager.unsubscribe_world(websocket, world_id)
+                    await websocket.send_text(
+                        json.dumps({"type": "unsubscribed", "channel": "world", "id": world_id})
+                    )
+            elif msg_type in ("subscribe_dm", "subscribe") and (
+                msg.get("conversation_id") or msg.get("channel") == "dm"
+            ):
+                conv_id = msg.get("conversation_id") or msg.get("id")
+                if isinstance(conv_id, int):
+                    ok = await connection_manager.subscribe_dm(websocket, conv_id)
+                    if ok:
+                        await websocket.send_text(
+                            json.dumps({"type": "subscribed", "channel": "dm", "id": conv_id})
+                        )
+                    else:
+                        await websocket.send_text(
+                            json.dumps({"type": "error", "message": f"Cannot subscribe to conversation {conv_id}"})
+                        )
+            elif msg_type in ("unsubscribe_dm", "unsubscribe") and (
+                msg.get("conversation_id") or msg.get("channel") == "dm"
+            ):
+                conv_id = msg.get("conversation_id") or msg.get("id")
+                if isinstance(conv_id, int):
+                    connection_manager.unsubscribe_dm(websocket, conv_id)
+                    await websocket.send_text(
+                        json.dumps({"type": "unsubscribed", "channel": "dm", "id": conv_id})
+                    )
+            else:
+                await websocket.send_text(json.dumps({"type": "error", "message": f"Unknown action: {msg_type}"}))
+
+    except WebSocketDisconnect:
+        pass
+    finally:
+        await connection_manager.disconnect(websocket)

backend/app/main.py

@@ -6,7 +6,12 @@ from fastapi import FastAPI
 from fastapi.middleware.cors import CORSMiddleware
 
 from app.config import settings
-from app.routers import auth, users, worlds, assets, avatar, world_content, internal
+from app.routers import (
+    auth, users, worlds, assets, avatar, world_content, internal,
+    presence, groups, social_friends, profiles, chat_dm, chat_reports,
+    chat_world, wallet, payments, marketplace,
+)
+from app.gateway import ws
 
 
 from app.services.game_servers import supervisor
@@ -44,6 +49,20 @@ app.include_router(world_content.router, prefix="/api/worlds", tags=["world-cont
 app.include_router(assets.router, prefix="/api/assets", tags=["assets"])
 app.include_router(avatar.router, prefix="/api/avatar", tags=["avatar"])
 app.include_router(internal.router, prefix="/api/internal", tags=["internal"])
+app.include_router(presence.router, prefix="/api/presence", tags=["presence"])
+app.include_router(groups.router, prefix="/api/groups", tags=["groups"])
+app.include_router(social_friends.router, prefix="/api/friends", tags=["friends"])
+app.include_router(profiles.router, prefix="/api/profile", tags=["profile"])
+app.include_router(chat_dm.router, prefix="/api/chat/dm", tags=["chat-dm"])
+app.include_router(chat_reports.chat_router, prefix="/api/chat", tags=["chat-reports"])
+app.include_router(chat_reports.moderation_router, prefix="/api/moderation", tags=["moderation"])
+app.include_router(chat_world.router, prefix="/api/chat", tags=["chat-world"])
+app.include_router(chat_world.router, prefix="/v1/chat", tags=["chat-world"])
+app.include_router(wallet.router, prefix="/api/wallet", tags=["wallet"])
+app.include_router(payments.router, prefix="/api/payments", tags=["payments"])
+app.include_router(marketplace.router, prefix="/api/marketplace", tags=["marketplace"])
+app.include_router(ws.router, prefix="/api", tags=["websocket"])
+app.include_router(ws.router, prefix="/v1", tags=["websocket"])
 
 
 @app.get("/api/health")

backend/app/models/__init__.py

@@ -4,8 +4,26 @@ from app.models.world import World
 from app.models.asset import Asset
 from app.models.avatar_loadout import AvatarLoadout
 from app.models.world_content import WorldRoom, WorldChunk, WorldChunkRevision
+from app.models.social import Friendship, Follow, Block, FriendshipStatus
+from app.models.chat import (
+    Conversation, ConversationParticipant, Message, MessageReport, ReportStatus,
+)
+from app.models.groups import Group, GroupMember, GroupRole
+from app.models.profile import Profile, ProfileFavorite, ProfileVisibility
+from app.models.wallet import Wallet, Transaction, TransactionType
+from app.models.marketplace import (
+    CatalogItem, MarketplaceListing, Purchase, CreatorBalance,
+    ItemType, ListingStatus, PurchaseStatus,
+)
 
 __all__ = [
     "User", "Session", "World", "Asset", "AvatarLoadout",
     "WorldRoom", "WorldChunk", "WorldChunkRevision",
+    "Friendship", "Follow", "Block", "FriendshipStatus",
+    "Conversation", "ConversationParticipant", "Message", "MessageReport", "ReportStatus",
+    "Group", "GroupMember", "GroupRole",
+    "Profile", "ProfileFavorite", "ProfileVisibility",
+    "Wallet", "Transaction", "TransactionType",
+    "CatalogItem", "MarketplaceListing", "Purchase", "CreatorBalance",
+    "ItemType", "ListingStatus", "PurchaseStatus",
 ]

backend/app/models/asset.py

@@ -23,7 +23,12 @@ class Asset(Base):
     name = Column(String(255), nullable=False)
     description = Column(Text, nullable=True)
     asset_type = Column(
-        ENUM(AssetType, name="asset_type", create_type=False),
+        ENUM(
+            AssetType,
+            name="asset_type",
+            create_type=False,
+            values_callable=lambda enum_cls: [e.value for e in enum_cls],
+        ),
         nullable=False,
     )
     file_path = Column(String(512), nullable=False)

backend/app/models/chat.py

@@ -0,0 +1,221 @@
+"""Chat: DM conversations and world/room chat, plus message reports.
+
+docs/planning/social.md §4/§5 (US-4). This module is models + schema only --
+text filtering, rate limiting, and the send/list/report/moderation endpoints
+belong to sibling tasks that depend on this one.
+
+Delete-behavior choices (mirrors ``app/models/world_content.py``'s
+established convention of preserving audit/history data over cascading it
+away):
+
+- ``conversations.user_a_id`` / ``user_b_id`` -> CASCADE. A DM conversation
+  is meaningless with one of its two (and only) participants gone, so
+  deleting either user removes the conversation outright, which in turn
+  cascades to its ``conversation_participants`` rows and its ``messages``.
+- ``conversation_participants.user_id`` -> CASCADE, ``.conversation_id`` ->
+  CASCADE. Pure join-table rows; they only make sense alongside both sides.
+- ``messages.conversation_id`` -> CASCADE. Deleting a conversation deletes
+  its message history with it.
+- ``messages.sender_id`` -> SET NULL (nullable). Unlike a DM conversation
+  (which dies with its participants above), world/room chat history and any
+  message under moderation review should survive the sender's account being
+  deleted -- the row just becomes attributed to no one, matching how
+  ``WorldChunk.updated_by_id`` / ``WorldChunkRevision.actor_id`` treat
+  actor references as SET NULL rather than cascading away history.
+- ``messages.world_id`` / ``room_id`` -> CASCADE. World/room chat has no
+  meaning once the world or room it was said in is gone; consistent with
+  ``WorldChunk``'s own CASCADE from both.
+- ``message_reports.message_id`` -> SET NULL (nullable). Same audit-trail
+  reasoning as ``WorldChunkRevision`` (world_content.py): a moderation
+  report is a record that something *was* said and reported, which must
+  outlive the underlying message being removed (e.g. as the moderation
+  action taken in response to the report itself).
+- ``message_reports.reporter_id`` / ``moderator_id`` -> SET NULL (nullable).
+  Actor references for an audit record; the report itself must survive
+  either account being deleted later, matching the actor-reference
+  convention above.
+"""
+import enum
+
+from sqlalchemy import (
+    Boolean,
+    CheckConstraint,
+    Column,
+    DateTime,
+    ForeignKey,
+    Index,
+    Integer,
+    Text,
+    UniqueConstraint,
+)
+from sqlalchemy.dialects.postgresql import ENUM
+from sqlalchemy.orm import relationship
+from sqlalchemy.sql import func
+
+from app.database import Base
+
+
+class ReportStatus(str, enum.Enum):
+    OPEN = "open"
+    RESOLVED = "resolved"
+    DISMISSED = "dismissed"
+
+
+class Conversation(Base):
+    """A DM conversation between exactly two users.
+
+    ``conversation_participants`` is the real roster (modeled as a join
+    table so a future group-DM schema change can widen it beyond two rows
+    without touching this table's shape), but a 2-party DM also needs a
+    cheap, DB-enforced "only one conversation per pair" guarantee, which a
+    plain join table can't express as a simple unique constraint. So the
+    pair is additionally denormalized here as ``user_a_id``/``user_b_id``,
+    always stored with the lower user id first (enforced by the check
+    constraint below); the API layer is responsible for normalizing the
+    pair before insert/lookup.
+    """
+
+    __tablename__ = "conversations"
+
+    id = Column(Integer, primary_key=True, index=True)
+    user_a_id = Column(
+        Integer, ForeignKey("users.id", ondelete="CASCADE"), nullable=False, index=True
+    )
+    user_b_id = Column(
+        Integer, ForeignKey("users.id", ondelete="CASCADE"), nullable=False, index=True
+    )
+    created_at = Column(DateTime(timezone=True), server_default=func.now(), nullable=False)
+    updated_at = Column(
+        DateTime(timezone=True), server_default=func.now(), onupdate=func.now(), nullable=False
+    )
+
+    participants = relationship(
+        "ConversationParticipant", back_populates="conversation", cascade="all, delete-orphan"
+    )
+    messages = relationship(
+        "Message", back_populates="conversation", cascade="all, delete-orphan"
+    )
+
+    __table_args__ = (
+        UniqueConstraint("user_a_id", "user_b_id", name="uq_conversations_pair"),
+        CheckConstraint("user_a_id < user_b_id", name="ck_conversations_ordered_pair"),
+    )
+
+
+class ConversationParticipant(Base):
+    """Join table of a conversation's members.
+
+    DMs are strictly 2-party today (enforced by ``Conversation``'s pair
+    columns above), but this is modeled as a real join table -- not folded
+    into ``Conversation`` -- so a later group-conversation feature can add
+    rows here without a schema change to this table.
+    """
+
+    __tablename__ = "conversation_participants"
+
+    id = Column(Integer, primary_key=True, index=True)
+    conversation_id = Column(
+        Integer, ForeignKey("conversations.id", ondelete="CASCADE"), nullable=False, index=True
+    )
+    user_id = Column(
+        Integer, ForeignKey("users.id", ondelete="CASCADE"), nullable=False, index=True
+    )
+    created_at = Column(DateTime(timezone=True), server_default=func.now(), nullable=False)
+    # DM unread tracking (app/routers/chat_dm.py, migration 0010): bumped to
+    # "now" whenever this participant fetches the conversation's history.
+    # Null means "never read" -- everything in the conversation is unread.
+    last_read_at = Column(DateTime(timezone=True), nullable=True)
+
+    conversation = relationship("Conversation", back_populates="participants")
+    user = relationship("User")
+
+    __table_args__ = (
+        UniqueConstraint(
+            "conversation_id", "user_id", name="uq_conversation_participants_pair"
+        ),
+    )
+
+
+class Message(Base):
+    """A chat message: either a DM (``conversation_id`` set) or a
+    world/room chat message (``conversation_id`` null, ``world_id`` set and
+    optionally ``room_id``).
+
+    ``world_id`` is denormalized onto every world/room message (mirroring
+    ``WorldChunk.world_id``) so world-scoped history queries don't need a
+    join through rooms; ``room_id`` narrows further to a specific room when
+    the world subdivides chat by room, and is null for world-wide chat.
+    """
+
+    __tablename__ = "messages"
+
+    id = Column(Integer, primary_key=True, index=True)
+    sender_id = Column(
+        Integer, ForeignKey("users.id", ondelete="SET NULL"), nullable=True, index=True
+    )
+    conversation_id = Column(
+        Integer, ForeignKey("conversations.id", ondelete="CASCADE"), nullable=True
+    )
+    world_id = Column(
+        Integer, ForeignKey("worlds.id", ondelete="CASCADE"), nullable=True
+    )
+    room_id = Column(
+        Integer, ForeignKey("world_rooms.id", ondelete="CASCADE"), nullable=True
+    )
+    body = Column(Text, nullable=False)
+    filtered = Column(Boolean, nullable=False, default=False, server_default="false")
+    created_at = Column(DateTime(timezone=True), server_default=func.now(), nullable=False)
+
+    sender = relationship("User")
+    conversation = relationship("Conversation", back_populates="messages")
+    world = relationship("World")
+    room = relationship("WorldRoom")
+    reports = relationship(
+        "MessageReport", back_populates="message", cascade="all, delete-orphan"
+    )
+
+    __table_args__ = (
+        Index("ix_messages_conversation_created", "conversation_id", "created_at"),
+        Index("ix_messages_world_created", "world_id", "created_at"),
+    )
+
+
+class MessageReport(Base):
+    """A moderation report filed against a message.
+
+    ``message_id`` is nullable with ``ON DELETE SET NULL`` (rather than
+    CASCADE) so the report -- the audit record that something was said and
+    flagged -- outlives the message row, including when the message's own
+    removal is the moderation action taken in response to this report.
+    """
+
+    __tablename__ = "message_reports"
+
+    id = Column(Integer, primary_key=True, index=True)
+    message_id = Column(
+        Integer, ForeignKey("messages.id", ondelete="SET NULL"), nullable=True, index=True
+    )
+    reporter_id = Column(
+        Integer, ForeignKey("users.id", ondelete="SET NULL"), nullable=True, index=True
+    )
+    reason = Column(Text, nullable=False)
+    status = Column(
+        ENUM(
+            ReportStatus,
+            name="message_report_status",
+            create_type=False,
+            values_callable=lambda enum_cls: [e.value for e in enum_cls],
+        ),
+        nullable=False,
+        default=ReportStatus.OPEN,
+        server_default=ReportStatus.OPEN.value,
+    )
+    moderator_id = Column(
+        Integer, ForeignKey("users.id", ondelete="SET NULL"), nullable=True, index=True
+    )
+    resolved_at = Column(DateTime(timezone=True), nullable=True)
+    created_at = Column(DateTime(timezone=True), server_default=func.now(), nullable=False)
+
+    message = relationship("Message", back_populates="reports")
+    reporter = relationship("User", foreign_keys=[reporter_id])
+    moderator = relationship("User", foreign_keys=[moderator_id])

backend/app/models/groups.py

@@ -0,0 +1,97 @@
+"""Groups: named groups with owner/admin/member roles.
+
+docs/planning/social.md §4/§5 (US-5). This module is models + schema only --
+create/join/leave, role authorization (only the owner may transfer ownership
+or promote/demote admins), and the group page aggregate endpoint belong to
+the API router task ("Groups API") that depends on this one.
+
+Delete-behavior choices:
+
+- ``groups.owner_id`` -> ``SET NULL`` (nullable). A group is a durable,
+  multi-member community, not content solely attributable to one person like
+  a ``World``/``Asset``. Cascading the group away (or hard-blocking the
+  owner's account deletion) would punish every other member for the owner's
+  choice to leave the platform. Instead the group and its full membership
+  list survive with ``owner_id`` nulled out; the sibling API task is
+  responsible for surfacing an ownerless group (e.g. prompting an admin to
+  claim ownership) the same way ``Message.sender_id`` / ``WorldChunk``'s
+  actor columns already treat "the actor is gone" as a survivable state
+  elsewhere in this schema.
+- ``group_members.group_id`` -> ``CASCADE``. A membership row is meaningless
+  without the group it belongs to; deleting a group deletes its roster,
+  mirroring ``ConversationParticipant.conversation_id`` in chat.py.
+- ``group_members.user_id`` -> ``CASCADE``. Deleting a user removes their own
+  membership rows wherever they appear, matching the join-table convention
+  used by ``ConversationParticipant.user_id`` and the social-graph tables
+  (``Friendship``/``Follow``/``Block``) for plain per-user references.
+"""
+import enum
+
+from sqlalchemy import Column, DateTime, ForeignKey, Integer, String, Text, UniqueConstraint
+from sqlalchemy.dialects.postgresql import ENUM
+from sqlalchemy.orm import relationship
+from sqlalchemy.sql import func
+
+from app.database import Base
+
+
+class GroupRole(str, enum.Enum):
+    OWNER = "owner"
+    ADMIN = "admin"
+    MEMBER = "member"
+
+
+class Group(Base):
+    """A named group. ``owner_id`` is nullable -- see module docstring for
+    why the group survives its owner's account deletion."""
+
+    __tablename__ = "groups"
+
+    id = Column(Integer, primary_key=True, index=True)
+    name = Column(String(100), nullable=False)
+    description = Column(Text, nullable=True)
+    owner_id = Column(
+        Integer, ForeignKey("users.id", ondelete="SET NULL"), nullable=True, index=True
+    )
+    created_at = Column(DateTime(timezone=True), server_default=func.now(), nullable=False)
+    updated_at = Column(
+        DateTime(timezone=True), server_default=func.now(), onupdate=func.now(), nullable=False
+    )
+
+    owner = relationship("User", back_populates="owned_groups")
+    members = relationship(
+        "GroupMember", back_populates="group", cascade="all, delete-orphan"
+    )
+
+
+class GroupMember(Base):
+    """A group's roster: one row per (group, user) with a role."""
+
+    __tablename__ = "group_members"
+
+    id = Column(Integer, primary_key=True, index=True)
+    group_id = Column(
+        Integer, ForeignKey("groups.id", ondelete="CASCADE"), nullable=False, index=True
+    )
+    user_id = Column(
+        Integer, ForeignKey("users.id", ondelete="CASCADE"), nullable=False, index=True
+    )
+    role = Column(
+        ENUM(
+            GroupRole,
+            name="group_role",
+            create_type=False,
+            values_callable=lambda enum_cls: [e.value for e in enum_cls],
+        ),
+        nullable=False,
+        default=GroupRole.MEMBER,
+        server_default=GroupRole.MEMBER.value,
+    )
+    joined_at = Column(DateTime(timezone=True), server_default=func.now(), nullable=False)
+
+    group = relationship("Group", back_populates="members")
+    user = relationship("User", back_populates="group_memberships")
+
+    __table_args__ = (
+        UniqueConstraint("group_id", "user_id", name="uq_group_members_pair"),
+    )

backend/app/models/marketplace.py

@@ -0,0 +1,155 @@
+"""Marketplace models: catalog items, listings, purchases, and creator balances.
+
+docs/planning/economy.md US-3, US-4 (task 166836d55365).
+"""
+
+from datetime import datetime, timezone
+import enum
+
+from sqlalchemy import (
+    BigInteger,
+    CheckConstraint,
+    Column,
+    DateTime,
+    Enum,
+    ForeignKey,
+    Integer,
+    String,
+    func,
+)
+from sqlalchemy.dialects.postgresql import JSONB
+from sqlalchemy.types import JSON
+from sqlalchemy.orm import relationship
+
+from app.database import Base
+
+
+class ItemType(str, enum.Enum):
+    asset = "asset"
+    avatar_item = "avatar_item"
+    experience_pass = "experience_pass"
+
+
+class ListingStatus(str, enum.Enum):
+    active = "active"
+    sold = "sold"
+    delisted = "delisted"
+    removed_by_moderation = "removed_by_moderation"
+
+
+class PurchaseStatus(str, enum.Enum):
+    pending_escrow = "pending_escrow"
+    completed = "completed"
+    refunded = "refunded"
+    reversed = "reversed"
+
+
+class CatalogItem(Base):
+    __tablename__ = "catalog_items"
+
+    id = Column(BigInteger, primary_key=True, autoincrement=True)
+    owner_id = Column(Integer, ForeignKey("users.id", ondelete="CASCADE"), nullable=False, index=True)
+    asset_id = Column(Integer, ForeignKey("assets.id", ondelete="SET NULL"), nullable=True, index=True)
+    item_type = Column(Enum(ItemType, name="catalog_item_type"), nullable=False)
+    name = Column(String(100), nullable=False)
+    description = Column(String(2000), nullable=True)
+    metadata_json = Column(JSONB().with_variant(JSON, "sqlite"), nullable=True)
+    created_at = Column(
+        DateTime(timezone=True),
+        nullable=False,
+        default=lambda: datetime.now(timezone.utc),
+        server_default=func.now(),
+    )
+
+    owner = relationship("User", foreign_keys=[owner_id])
+    asset = relationship("Asset", foreign_keys=[asset_id])
+    listings = relationship("MarketplaceListing", back_populates="catalog_item", cascade="all, delete-orphan")
+
+
+class MarketplaceListing(Base):
+    __tablename__ = "marketplace_listings"
+
+    id = Column(BigInteger, primary_key=True, autoincrement=True)
+    catalog_item_id = Column(BigInteger, ForeignKey("catalog_items.id", ondelete="CASCADE"), nullable=False, index=True)
+    seller_id = Column(Integer, ForeignKey("users.id", ondelete="CASCADE"), nullable=False, index=True)
+    price = Column(BigInteger, nullable=False)
+    status = Column(
+        Enum(ListingStatus, name="marketplace_listing_status"),
+        nullable=False,
+        default=ListingStatus.active,
+        server_default=ListingStatus.active.value,
+    )
+    created_at = Column(
+        DateTime(timezone=True),
+        nullable=False,
+        default=lambda: datetime.now(timezone.utc),
+        server_default=func.now(),
+    )
+    updated_at = Column(
+        DateTime(timezone=True),
+        nullable=False,
+        default=lambda: datetime.now(timezone.utc),
+        onupdate=lambda: datetime.now(timezone.utc),
+        server_default=func.now(),
+    )
+
+    __table_args__ = (
+        CheckConstraint("price > 0", name="check_listing_price_positive"),
+    )
+
+    catalog_item = relationship("CatalogItem", back_populates="listings")
+    seller = relationship("User", foreign_keys=[seller_id])
+
+
+class Purchase(Base):
+    __tablename__ = "purchases"
+
+    id = Column(BigInteger, primary_key=True, autoincrement=True)
+    listing_id = Column(BigInteger, ForeignKey("marketplace_listings.id", ondelete="SET NULL"), nullable=True, index=True)
+    buyer_id = Column(Integer, ForeignKey("users.id", ondelete="CASCADE"), nullable=False, index=True)
+    seller_id = Column(Integer, ForeignKey("users.id", ondelete="CASCADE"), nullable=False, index=True)
+    price = Column(BigInteger, nullable=False)
+    platform_fee = Column(BigInteger, nullable=False)
+    seller_net = Column(BigInteger, nullable=False)
+    status = Column(
+        Enum(PurchaseStatus, name="purchase_status"),
+        nullable=False,
+        default=PurchaseStatus.pending_escrow,
+        server_default=PurchaseStatus.pending_escrow.value,
+    )
+    escrow_hold_until = Column(DateTime(timezone=True), nullable=True)
+    created_at = Column(
+        DateTime(timezone=True),
+        nullable=False,
+        default=lambda: datetime.now(timezone.utc),
+        server_default=func.now(),
+    )
+
+    listing = relationship("MarketplaceListing", foreign_keys=[listing_id])
+    buyer = relationship("User", foreign_keys=[buyer_id])
+    seller = relationship("User", foreign_keys=[seller_id])
+
+
+class CreatorBalance(Base):
+    __tablename__ = "creator_balances"
+
+    id = Column(BigInteger, primary_key=True, autoincrement=True)
+    user_id = Column(Integer, ForeignKey("users.id", ondelete="CASCADE"), unique=True, nullable=False, index=True)
+    available = Column(BigInteger, nullable=False, default=0, server_default="0")
+    pending = Column(BigInteger, nullable=False, default=0, server_default="0")
+    lifetime_earned = Column(BigInteger, nullable=False, default=0, server_default="0")
+    updated_at = Column(
+        DateTime(timezone=True),
+        nullable=False,
+        default=lambda: datetime.now(timezone.utc),
+        onupdate=lambda: datetime.now(timezone.utc),
+        server_default=func.now(),
+    )
+
+    __table_args__ = (
+        CheckConstraint("available >= 0", name="check_creator_available_non_negative"),
+        CheckConstraint("pending >= 0", name="check_creator_pending_non_negative"),
+        CheckConstraint("lifetime_earned >= 0", name="check_creator_lifetime_non_negative"),
+    )
+
+    user = relationship("User", foreign_keys=[user_id])

backend/app/models/profile.py

@@ -0,0 +1,129 @@
+"""User profile: bio, avatar reference, privacy settings, favorite worlds.
+
+This module is models + migration only -- the public profile view endpoint
+(``GET /api/profile/{user_id}``, which will need to interpret ``privacy_json``
+against the viewer's relationship to the owner) belongs to a sibling task
+that depends on this one. This task only owns the authenticated-owner
+read/write endpoints (``/api/profile/me`` and its ``favorites`` sub-resource).
+
+Design choices:
+
+- ``profiles.user_id`` is both the primary key and the FK to ``users.id``
+  (``ondelete="CASCADE"``) -- exactly one profile row per user, following the
+  same one-row-per-user shape as ``AvatarLoadout`` (app/models/avatar_loadout.py).
+  The row is created lazily (upserted) on first ``PUT /api/profile/me``
+  rather than at registration time, again mirroring ``AvatarLoadout``.
+- ``avatar_asset_id`` -> ``assets.id`` with ``ondelete="SET NULL"``. A
+  profile's chosen "avatar picture" asset is a soft reference: if the
+  underlying asset is later deleted the profile shouldn't be destroyed or
+  left pointing at a dangling id, it should just fall back to "no avatar
+  picture set" (nullable). The API layer additionally validates on write
+  that the referenced asset actually exists (existence is not enforced by
+  the FK alone at the API layer, since the FK only stops inserts of a
+  nonexistent id -- it doesn't tell the caller *why* their PUT failed).
+- ``bio`` is ``Text`` with the 500-char cap enforced at the API/schema layer
+  (Pydantic ``max_length``), matching how ``StatusUpdate.status_message`` in
+  presence.py enforces its length cap in the router rather than the schema.
+- ``privacy_json`` is JSONB (project convention for document-shaped fields --
+  see avatar_loadout.py, world_content.py) holding exactly three keys, each a
+  ``ProfileVisibility`` enum value (stored as its string value in JSON, not a
+  Postgres ENUM type -- there's no need for a DB-level enum since this is a
+  small, entirely API-validated document, and a plain JSONB column is easier
+  to extend with more privacy keys later without a migration):
+    - ``profile_visibility``: who can view the profile at all.
+    - ``friends_list_visibility``: who can see the user's friends list.
+    - ``favorites_visibility``: who can see the user's favorited worlds.
+  Each value is one of "public", "friends", "private". Defaults (applied when
+  a profile is first created) are all "public" -- the least surprising
+  default for a new social feature, matching the "everything visible unless
+  you lock it down" posture other social features here take by default
+  (e.g. presence/status has no privacy gate at all yet).
+- Favorites use a join table (``profile_favorites``: ``user_id`` + ``world_id``,
+  composite PK) rather than a JSON array column. A plain FK join table gets
+  referential integrity for free (a favorited world that's later deleted
+  disappears from favorites automatically via ON DELETE CASCADE, matching
+  how ``World.assets``/``World.rooms`` cascade), lets Postgres enforce
+  "no duplicate favorite" via the composite PK instead of API-layer
+  deduplication, and keeps "does this world still exist" as a DB invariant
+  rather than something every reader has to re-check against a JSON blob.
+  The tradeoff (an extra table/join vs. a single JSON column) is worth it
+  here because favorites are a list of foreign-key references, not a
+  free-form document -- the exact case join tables suit better than JSONB.
+"""
+import enum
+
+from sqlalchemy import Column, Integer, ForeignKey, Text, DateTime
+from sqlalchemy.dialects.postgresql import JSONB
+from sqlalchemy.orm import relationship
+from sqlalchemy.sql import func
+
+from app.database import Base
+
+
+class ProfileVisibility(str, enum.Enum):
+    PUBLIC = "public"
+    FRIENDS = "friends"
+    PRIVATE = "private"
+
+
+# Applied when a profile is created for the first time (lazy upsert on the
+# first PUT /api/profile/me). Keys match the three privacy_json fields
+# documented above.
+DEFAULT_PRIVACY: dict = {
+    "profile_visibility": ProfileVisibility.PUBLIC.value,
+    "friends_list_visibility": ProfileVisibility.PUBLIC.value,
+    "favorites_visibility": ProfileVisibility.PUBLIC.value,
+}
+
+BIO_MAX_LEN = 500
+
+
+class Profile(Base):
+    """One row per user: bio, avatar picture reference, privacy settings."""
+
+    __tablename__ = "profiles"
+
+    user_id = Column(
+        Integer,
+        ForeignKey("users.id", ondelete="CASCADE"),
+        primary_key=True,
+    )
+    avatar_asset_id = Column(
+        Integer,
+        ForeignKey("assets.id", ondelete="SET NULL"),
+        nullable=True,
+    )
+    bio = Column(Text, nullable=True)
+    privacy_json = Column(JSONB, nullable=False, server_default="{}")
+    created_at = Column(DateTime(timezone=True), server_default=func.now(), nullable=False)
+    updated_at = Column(DateTime(timezone=True), server_default=func.now(), onupdate=func.now(), nullable=False)
+
+    user = relationship("User", back_populates="profile")
+    avatar_asset = relationship("Asset")
+    # Deliberately no ORM relationship to ProfileFavorite here: profiles and
+    # profile_favorites both independently FK users.id (no direct FK between
+    # the two tables), and the router only ever needs to query/replace a
+    # user's favorites by user_id directly -- not traverse it off a loaded
+    # Profile object. Keeping it a plain queryable table avoids a
+    # hand-spelled, easy-to-get-wrong primaryjoin for no real benefit.
+
+
+class ProfileFavorite(Base):
+    """A user's favorited world. Composite PK -- see module docstring for why
+    this is a join table rather than a JSON array column."""
+
+    __tablename__ = "profile_favorites"
+
+    user_id = Column(
+        Integer,
+        ForeignKey("users.id", ondelete="CASCADE"),
+        primary_key=True,
+    )
+    world_id = Column(
+        Integer,
+        ForeignKey("worlds.id", ondelete="CASCADE"),
+        primary_key=True,
+    )
+    created_at = Column(DateTime(timezone=True), server_default=func.now(), nullable=False)
+
+    world = relationship("World")

backend/app/models/social.py

@@ -0,0 +1,106 @@
+"""Social graph: friendships, follows, blocks.
+
+docs/planning/social.md §4/§5 (US-1). Friends = mutual (request -> accept),
+Follow = one-way (no approval), Block = hard deny. This module is models +
+schema only -- the request/accept/block business logic (idempotent
+duplicate/self handling, removing an existing friendship/follow on block,
+etc.) belongs to the API router task that depends on this one.
+"""
+import enum
+
+from sqlalchemy import Column, Integer, ForeignKey, DateTime, UniqueConstraint
+from sqlalchemy.dialects.postgresql import ENUM
+from sqlalchemy.orm import relationship
+from sqlalchemy.sql import func
+
+from app.database import Base
+
+
+class FriendshipStatus(str, enum.Enum):
+    PENDING = "pending"
+    ACCEPTED = "accepted"
+
+
+class Friendship(Base):
+    """A friend request, directional until accepted.
+
+    ``requester_id`` sent the request to ``addressee_id``. Once accepted the
+    friendship is mutual, but the row stays directional (who asked whom) for
+    audit purposes; the API layer treats it as symmetric once accepted.
+    """
+
+    __tablename__ = "friendships"
+
+    id = Column(Integer, primary_key=True, index=True)
+    requester_id = Column(
+        Integer, ForeignKey("users.id", ondelete="CASCADE"), nullable=False, index=True
+    )
+    addressee_id = Column(
+        Integer, ForeignKey("users.id", ondelete="CASCADE"), nullable=False, index=True
+    )
+    status = Column(
+        ENUM(
+            FriendshipStatus,
+            name="friendship_status",
+            create_type=False,
+            values_callable=lambda enum_cls: [e.value for e in enum_cls],
+        ),
+        nullable=False,
+        default=FriendshipStatus.PENDING,
+        server_default=FriendshipStatus.PENDING.value,
+    )
+    created_at = Column(DateTime(timezone=True), server_default=func.now(), nullable=False)
+    updated_at = Column(DateTime(timezone=True), server_default=func.now(), onupdate=func.now(), nullable=False)
+
+    requester = relationship("User", foreign_keys=[requester_id], back_populates="sent_friend_requests")
+    addressee = relationship("User", foreign_keys=[addressee_id], back_populates="received_friend_requests")
+
+    __table_args__ = (
+        UniqueConstraint("requester_id", "addressee_id", name="uq_friendships_pair"),
+    )
+
+
+class Follow(Base):
+    """A one-way follow relationship: ``follower_id`` follows ``followed_id``."""
+
+    __tablename__ = "follows"
+
+    id = Column(Integer, primary_key=True, index=True)
+    follower_id = Column(
+        Integer, ForeignKey("users.id", ondelete="CASCADE"), nullable=False, index=True
+    )
+    followed_id = Column(
+        Integer, ForeignKey("users.id", ondelete="CASCADE"), nullable=False, index=True
+    )
+    created_at = Column(DateTime(timezone=True), server_default=func.now(), nullable=False)
+    updated_at = Column(DateTime(timezone=True), server_default=func.now(), onupdate=func.now(), nullable=False)
+
+    follower = relationship("User", foreign_keys=[follower_id], back_populates="following")
+    followed = relationship("User", foreign_keys=[followed_id], back_populates="followers")
+
+    __table_args__ = (
+        UniqueConstraint("follower_id", "followed_id", name="uq_follows_pair"),
+    )
+
+
+class Block(Base):
+    """A hard deny: ``blocker_id`` has blocked ``blocked_id``."""
+
+    __tablename__ = "blocks"
+
+    id = Column(Integer, primary_key=True, index=True)
+    blocker_id = Column(
+        Integer, ForeignKey("users.id", ondelete="CASCADE"), nullable=False, index=True
+    )
+    blocked_id = Column(
+        Integer, ForeignKey("users.id", ondelete="CASCADE"), nullable=False, index=True
+    )
+    created_at = Column(DateTime(timezone=True), server_default=func.now(), nullable=False)
+    updated_at = Column(DateTime(timezone=True), server_default=func.now(), onupdate=func.now(), nullable=False)
+
+    blocker = relationship("User", foreign_keys=[blocker_id], back_populates="blocks_initiated")
+    blocked = relationship("User", foreign_keys=[blocked_id], back_populates="blocked_by")
+
+    __table_args__ = (
+        UniqueConstraint("blocker_id", "blocked_id", name="uq_blocks_pair"),
+    )

backend/app/models/user.py

@@ -1,7 +1,7 @@
 from datetime import date
 from typing import Optional
 
-from sqlalchemy import Column, Integer, String, Boolean, DateTime, Date
+from sqlalchemy import Column, Integer, String, Boolean, DateTime, Date, Text
 from sqlalchemy.orm import relationship
 from sqlalchemy.sql import func
 
@@ -20,6 +20,10 @@ class User(Base):
     created_at = Column(DateTime(timezone=True), server_default=func.now())
     updated_at = Column(DateTime(timezone=True), onupdate=func.now())
 
+    # Presence / status (backend/app/services/presence.py, app/routers/presence.py)
+    last_seen_at = Column(DateTime(timezone=True), nullable=True)
+    status_message = Column(Text, nullable=True)
+
     sessions = relationship("Session", back_populates="user", cascade="all, delete-orphan")
     refresh_tokens = relationship("RefreshToken", back_populates="user", cascade="all, delete-orphan")
     worlds = relationship("World", back_populates="owner")
@@ -31,6 +35,63 @@ class User(Base):
         cascade="all, delete-orphan",
     )
 
+    # Profile (app/models/profile.py): bio/avatar picture/privacy + favorites.
+    profile = relationship(
+        "Profile",
+        back_populates="user",
+        uselist=False,
+        cascade="all, delete-orphan",
+    )
+
+    # Social graph (docs/planning/social.md US-1; app/models/social.py)
+    sent_friend_requests = relationship(
+        "Friendship",
+        foreign_keys="Friendship.requester_id",
+        back_populates="requester",
+        cascade="all, delete-orphan",
+    )
+    received_friend_requests = relationship(
+        "Friendship",
+        foreign_keys="Friendship.addressee_id",
+        back_populates="addressee",
+        cascade="all, delete-orphan",
+    )
+    following = relationship(
+        "Follow",
+        foreign_keys="Follow.follower_id",
+        back_populates="follower",
+        cascade="all, delete-orphan",
+    )
+    followers = relationship(
+        "Follow",
+        foreign_keys="Follow.followed_id",
+        back_populates="followed",
+        cascade="all, delete-orphan",
+    )
+    blocks_initiated = relationship(
+        "Block",
+        foreign_keys="Block.blocker_id",
+        back_populates="blocker",
+        cascade="all, delete-orphan",
+    )
+    blocked_by = relationship(
+        "Block",
+        foreign_keys="Block.blocked_id",
+        back_populates="blocked",
+        cascade="all, delete-orphan",
+    )
+
+    # Groups (docs/planning/social.md US-5; app/models/groups.py)
+    owned_groups = relationship(
+        "Group",
+        back_populates="owner",
+    )
+    group_memberships = relationship(
+        "GroupMember",
+        back_populates="user",
+        cascade="all, delete-orphan",
+    )
+
     @property
     def is_adult(self) -> bool:
         """Return True if the user is 18 or older based on date_of_birth."""

backend/app/models/wallet.py

@@ -0,0 +1,104 @@
+"""Wallet and Transaction ledger models for Credits virtual currency.
+
+docs/planning/economy.md US-1.
+"""
+
+from datetime import datetime, timezone
+import enum
+
+from sqlalchemy import (
+    BigInteger,
+    CheckConstraint,
+    Column,
+    DateTime,
+    Enum,
+    ForeignKey,
+    Integer,
+    String,
+    func,
+)
+from sqlalchemy.dialects.postgresql import JSONB
+from sqlalchemy.types import JSON
+from sqlalchemy.orm import relationship
+
+from app.database import Base
+
+
+class TransactionType(str, enum.Enum):
+    credit_purchase = "credit_purchase"
+    marketplace_purchase = "marketplace_purchase"
+    marketplace_sale = "marketplace_sale"
+    escrow_release = "escrow_release"
+    payout = "payout"
+    refund = "refund"
+    admin_adjustment = "admin_adjustment"
+
+
+class Wallet(Base):
+    __tablename__ = "wallets"
+
+    id = Column(BigInteger, primary_key=True, autoincrement=True)
+    user_id = Column(
+        Integer,
+        ForeignKey("users.id", ondelete="CASCADE"),
+        unique=True,
+        nullable=False,
+        index=True,
+    )
+    balance = Column(BigInteger, nullable=False, default=0, server_default="0")
+    created_at = Column(
+        DateTime(timezone=True),
+        nullable=False,
+        default=lambda: datetime.now(timezone.utc),
+        server_default=func.now(),
+    )
+    updated_at = Column(
+        DateTime(timezone=True),
+        nullable=False,
+        default=lambda: datetime.now(timezone.utc),
+        onupdate=lambda: datetime.now(timezone.utc),
+        server_default=func.now(),
+    )
+
+    __table_args__ = (
+        CheckConstraint("balance >= 0", name="check_wallet_balance_non_negative"),
+    )
+
+    user = relationship("User", backref="wallet", uselist=False)
+    transactions = relationship(
+        "Transaction",
+        back_populates="wallet",
+        cascade="all, delete-orphan",
+        order_by="Transaction.created_at.desc()",
+    )
+
+
+class Transaction(Base):
+    __tablename__ = "transactions"
+
+    id = Column(BigInteger, primary_key=True, autoincrement=True)
+    wallet_id = Column(
+        BigInteger,
+        ForeignKey("wallets.id", ondelete="CASCADE"),
+        nullable=False,
+        index=True,
+    )
+    type = Column(
+        Enum(TransactionType, name="transaction_type"),
+        nullable=False,
+    )
+    amount = Column(BigInteger, nullable=False)  # signed integer: positive = credit, negative = debit
+    balance_after = Column(BigInteger, nullable=False)
+    reference_type = Column(String, nullable=True)  # e.g. "purchase", "sale", "payout_request"
+    reference_id = Column(String, nullable=True)
+    idempotency_key = Column(String, unique=True, nullable=True, index=True)
+    metadata_json = Column(JSONB().with_variant(JSON, "sqlite"), nullable=True)
+    created_at = Column(
+        DateTime(timezone=True),
+        nullable=False,
+        default=lambda: datetime.now(timezone.utc),
+        server_default=func.now(),
+        index=True,
+    )
+
+    wallet = relationship("Wallet", back_populates="transactions")

backend/app/rate_limit.py

@@ -54,6 +54,12 @@ def _client_key(request: Request) -> str:
 # brute-forcer.
 _auth_limiter = SlidingWindowLimiter(max_hits=10, window_seconds=60)
 
+# Every limiter in the process -- named limits built via `rate_limit()`
+# below register themselves here too, so `reset_all()` (the test hook) and
+# any future process-wide accounting stay correct without each caller
+# having to remember to wire it up.
+_registered_limiters: list[SlidingWindowLimiter] = [_auth_limiter]
+
 
 async def auth_rate_limit(request: Request) -> None:
     """FastAPI dependency: rate-limit auth attempts per client IP.
@@ -68,6 +74,41 @@ async def auth_rate_limit(request: Request) -> None:
     _auth_limiter.check(f"auth:{_client_key(request)}")
 
 
+def rate_limit(name: str, *, max_hits: int, window_seconds: float):
+    """Build a named, per-client-IP FastAPI rate-limit dependency.
+
+    Generalizes the ``auth_rate_limit`` pattern above for other endpoints
+    (e.g. chat send, message report) that want their own independent cap:
+
+        report_rate_limit = rate_limit("message_report", max_hits=5, window_seconds=60)
+
+        @router.post("/report", dependencies=[Depends(report_rate_limit)])
+        ...
+
+    Each call gets its own ``SlidingWindowLimiter`` -- counters for one
+    named limit never bleed into another, even for the same client IP --
+    and reuses ``SlidingWindowLimiter.check`` for the actual sliding-window
+    accounting and the 429 + ``Retry-After`` response. Like
+    ``auth_rate_limit``, the returned dependency is a no-op when
+    ``settings.RATE_LIMIT_ENABLED`` is false, so the checkpoint smoke suite
+    (one client IP for the whole run) doesn't trip on it.
+
+    ``name`` only needs to be unique within the process; it namespaces the
+    per-IP key so it doesn't collide with ``auth_rate_limit`` or any other
+    named limit.
+    """
+    limiter = SlidingWindowLimiter(max_hits=max_hits, window_seconds=window_seconds)
+    _registered_limiters.append(limiter)
+
+    async def _dependency(request: Request) -> None:
+        if not settings.RATE_LIMIT_ENABLED:
+            return
+        limiter.check(f"{name}:{_client_key(request)}")
+
+    return _dependency
+
+
 def reset_all() -> None:
     """Test hook."""
-    _auth_limiter.reset()
+    for limiter in _registered_limiters:
+        limiter.reset()

backend/app/routers/chat_dm.py

@@ -0,0 +1,399 @@
+"""Direct-message (DM) chat router.
+
+docs/planning/social.md §4/§5 (US-4). Builds the send/list REST surface on
+top of ``app/models/chat.py`` (Conversation/ConversationParticipant/Message,
+already merged), ``app/services/text_filter.py`` (already merged), and
+``app/rate_limit.py`` (already merged).
+
+Endpoints:
+- POST /api/chat/dm/{user_id}/messages     -- send a DM to ``user_id``
+- GET  /api/chat/dm/{user_id}/messages     -- paginated history with ``user_id``
+- GET  /api/chat/dm/conversations          -- list the caller's conversations
+
+Scope/boundaries (per task): REST send/list only, no WebSocket/real-time
+delivery (separate task), no world/room chat (separate sibling task; that
+uses the same ``Message`` table but with ``world_id``/``room_id`` set and
+``conversation_id`` null).
+
+Design decisions this task owns:
+
+- **Blocking.** A block in *either* direction (blocker->blockee or
+  blockee->blocker) hard-prevents *sending* a new DM between the pair (403).
+  It does not hide history the pair already has -- ``GET .../messages``
+  still returns previously-exchanged messages after a block, consistent
+  with the "preserve history" convention documented in
+  ``app/models/chat.py``'s module docstring. Only sending is blocked.
+- **Text filtering.** Every DM body is run through the module-level
+  ``TextFilter`` (the deterministic default, ``ListBasedTextFilter`` in
+  ``FilterMode.REDACT``) before storing:
+    - ALLOW -> store the body as-is, ``filtered=False``.
+    - REDACT -> store ``filtered_text`` (matched spans starred out),
+      ``filtered=True``.
+    - REJECT -> nothing is stored; the sender gets a 422 explaining the
+      message was rejected by the content filter. (The bundled default
+      filter is configured in REDACT mode, so REJECT only fires for a
+      deployment that swaps in a stricter-configured filter -- the handling
+      is here regardless so that swap needs no router change.)
+- **Rate limiting.** Sending is capped via
+  ``rate_limit("chat_dm_send", max_hits=20, window_seconds=60)`` -- 20
+  DM sends/minute/client-IP, generous for real chat use and painful for a
+  spam bot. A no-op when ``settings.RATE_LIMIT_ENABLED`` is false (see
+  ``app/rate_limit.py``), matching every other rate-limited endpoint.
+- **Unread tracking.** A last-read timestamp per participant
+  (``ConversationParticipant.last_read_at``, migration 0010). Fetching a
+  conversation's *latest* page of history (``GET .../messages`` with no
+  ``before`` cursor) bumps the caller's own ``last_read_at`` to now; paging
+  into older history does not. ``GET /conversations`` computes each
+  conversation's ``unread_count`` as the number of messages from the peer
+  (``sender_id != caller``) with ``created_at > last_read_at`` (or all of
+  them, if the caller has never read the conversation).
+- **Pagination.**
+    - History (``GET {user_id}/messages``): cursor-based, newest-first.
+      ``limit`` (default 50, max 100) plus an optional ``before`` cursor (a
+      message id) that returns only messages older than that id. Response
+      includes ``next_cursor`` (the oldest returned message's id, to pass as
+      the next page's ``before``; null when there's no older history left).
+    - Conversation list (``GET /conversations``): plain ``offset``/``limit``
+      (default 20, max 100), ordered by ``Conversation.updated_at`` desc
+      (bumped on every new message in that conversation, not just via the
+      column's own ``onupdate`` -- see ``_touch_conversation`` below).
+- Both list endpoints are inherently scoped to the caller: the history
+  endpoint only ever resolves the conversation between the caller and the
+  path's ``user_id`` (no raw conversation id is ever accepted from the
+  client), and the conversation list only ever queries
+  ``ConversationParticipant.user_id == caller``. There is no way for a
+  client to address another pair's conversation.
+"""
+
+from __future__ import annotations
+
+from datetime import datetime, timezone
+from typing import Annotated
+
+from fastapi import APIRouter, Depends, HTTPException, Query, status
+from pydantic import BaseModel, Field
+from sqlalchemy import and_, func, or_, select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.database import get_db
+from app.dependencies import CurrentUser
+from app.models.chat import Conversation, ConversationParticipant, Message
+from app.models.social import Block
+from app.models.user import User
+from app.rate_limit import rate_limit
+from app.services.chat_pubsub import publish_dm_chat_event
+from app.services.text_filter import FilterAction, default_text_filter
+
+router = APIRouter()
+
+DbDep = Annotated[AsyncSession, Depends(get_db)]
+
+_text_filter = default_text_filter()
+chat_dm_send_rate_limit = rate_limit("chat_dm_send", max_hits=20, window_seconds=60)
+
+_BODY_MAX_LEN = 4000
+
+# ──────────────────────────── Pydantic schemas ────────────────────────────
+
+
+class SendDMRequest(BaseModel):
+    body: str = Field(..., min_length=1, max_length=_BODY_MAX_LEN)
+
+
+class DMMessageResponse(BaseModel):
+    id: int
+    conversation_id: int
+    sender_id: int
+    recipient_id: int
+    body: str
+    filtered: bool
+    created_at: datetime
+
+    model_config = {"from_attributes": True}
+
+
+class DMMessageListResponse(BaseModel):
+    messages: list[DMMessageResponse]
+    next_cursor: int | None = None
+
+
+class DMConversationSummary(BaseModel):
+    conversation_id: int
+    peer_id: int
+    peer_username: str
+    last_message: DMMessageResponse | None
+    unread_count: int
+    updated_at: datetime
+
+
+class DMConversationListResponse(BaseModel):
+    conversations: list[DMConversationSummary]
+    total: int
+
+
+# ──────────────────────────────── Helpers ──────────────────────────────────
+
+
+async def _get_target_user(db: AsyncSession, user_id: int) -> User:
+    result = await db.execute(select(User).where(User.id == user_id))
+    user = result.scalar_one_or_none()
+    if user is None:
+        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="User not found")
+    return user
+
+
+async def _is_blocked_either_direction(db: AsyncSession, user_a: int, user_b: int) -> bool:
+    result = await db.execute(
+        select(Block.id).where(
+            or_(
+                and_(Block.blocker_id == user_a, Block.blocked_id == user_b),
+                and_(Block.blocker_id == user_b, Block.blocked_id == user_a),
+            )
+        ).limit(1)
+    )
+    return result.scalar_one_or_none() is not None
+
+
+async def _get_or_create_conversation(
+    db: AsyncSession, user_a_id: int, user_b_id: int
+) -> Conversation:
+    lo, hi = sorted((user_a_id, user_b_id))
+    result = await db.execute(
+        select(Conversation).where(
+            Conversation.user_a_id == lo, Conversation.user_b_id == hi
+        )
+    )
+    conversation = result.scalar_one_or_none()
+    if conversation is not None:
+        return conversation
+
+    conversation = Conversation(user_a_id=lo, user_b_id=hi)
+    db.add(conversation)
+    await db.flush()  # assign conversation.id
+    db.add(ConversationParticipant(conversation_id=conversation.id, user_id=lo))
+    db.add(ConversationParticipant(conversation_id=conversation.id, user_id=hi))
+    await db.flush()
+    return conversation
+
+
+async def _get_participant(
+    db: AsyncSession, conversation_id: int, user_id: int
+) -> ConversationParticipant | None:
+    result = await db.execute(
+        select(ConversationParticipant).where(
+            ConversationParticipant.conversation_id == conversation_id,
+            ConversationParticipant.user_id == user_id,
+        )
+    )
+    return result.scalar_one_or_none()
+
+
+def _peer_id(conversation: Conversation, self_id: int) -> int:
+    return conversation.user_b_id if conversation.user_a_id == self_id else conversation.user_a_id
+
+
+def _touch_conversation(conversation: Conversation) -> None:
+    """Bump ``updated_at`` explicitly.
+
+    ``Conversation.updated_at`` has ``onupdate=func.now()``, but that only
+    fires when an UPDATE statement touches the ``conversations`` row itself
+    -- inserting a ``Message`` row alone never does. Explicitly dirtying the
+    column here is what actually keeps "most recently active conversation"
+    ordering correct for ``GET /conversations``.
+    """
+    conversation.updated_at = datetime.now(timezone.utc)
+
+
+def _to_message_response(message: Message, recipient_id: int) -> DMMessageResponse:
+    return DMMessageResponse(
+        id=message.id,
+        conversation_id=message.conversation_id,
+        sender_id=message.sender_id,
+        recipient_id=recipient_id,
+        body=message.body,
+        filtered=message.filtered,
+        created_at=message.created_at,
+    )
+
+
+# ──────────────────────────────── Endpoints ────────────────────────────────
+
+
+@router.post(
+    "/{user_id}/messages",
+    response_model=DMMessageResponse,
+    status_code=status.HTTP_201_CREATED,
+    dependencies=[Depends(chat_dm_send_rate_limit)],
+)
+async def send_dm(
+    user_id: int,
+    body: SendDMRequest,
+    current_user: CurrentUser,
+    db: DbDep,
+):
+    """Send a DM to ``user_id``."""
+    if user_id == current_user.id:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST, detail="Cannot send a DM to yourself"
+        )
+
+    await _get_target_user(db, user_id)
+
+    if await _is_blocked_either_direction(db, current_user.id, user_id):
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail="Cannot message this user",
+        )
+
+    result = _text_filter.check(body.body)
+    if result.action is FilterAction.REJECT:
+        raise HTTPException(
+            status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
+            detail="Message rejected by the content filter.",
+        )
+
+    conversation = await _get_or_create_conversation(db, current_user.id, user_id)
+
+    message = Message(
+        sender_id=current_user.id,
+        conversation_id=conversation.id,
+        body=result.filtered_text,
+        filtered=(result.action is FilterAction.REDACT),
+    )
+    db.add(message)
+    _touch_conversation(conversation)
+    await db.commit()
+    await db.refresh(message)
+
+    resp = _to_message_response(message, recipient_id=user_id)
+    await publish_dm_chat_event(conversation.id, resp.model_dump(mode="json"))
+    return resp
+
+
+@router.get("/{user_id}/messages", response_model=DMMessageListResponse)
+async def get_dm_history(
+    user_id: int,
+    current_user: CurrentUser,
+    db: DbDep,
+    limit: int = Query(50, ge=1, le=100),
+    before: int | None = Query(
+        None, description="Return messages older than this message id (pagination cursor)."
+    ),
+):
+    """Paginated DM history between the caller and ``user_id``, newest first.
+
+    Marks the conversation as read (bumps the caller's ``last_read_at``) only
+    when fetching the first page (``before`` omitted) -- paging into older
+    history doesn't affect unread state.
+    """
+    await _get_target_user(db, user_id)
+
+    lo, hi = sorted((current_user.id, user_id))
+    conv_result = await db.execute(
+        select(Conversation).where(Conversation.user_a_id == lo, Conversation.user_b_id == hi)
+    )
+    conversation = conv_result.scalar_one_or_none()
+    if conversation is None:
+        # No conversation yet -- nothing exchanged, not an error.
+        return DMMessageListResponse(messages=[], next_cursor=None)
+
+    stmt = select(Message).where(Message.conversation_id == conversation.id)
+    if before is not None:
+        stmt = stmt.where(Message.id < before)
+    stmt = stmt.order_by(Message.id.desc()).limit(limit + 1)
+
+    rows = (await db.execute(stmt)).scalars().all()
+    has_more = len(rows) > limit
+    page = rows[:limit]
+    next_cursor = page[-1].id if has_more and page else None
+
+    if before is None:
+        participant = await _get_participant(db, conversation.id, current_user.id)
+        if participant is not None:
+            participant.last_read_at = datetime.now(timezone.utc)
+            await db.commit()
+
+    return DMMessageListResponse(
+        messages=[_to_message_response(m, recipient_id=user_id) for m in page],
+        next_cursor=next_cursor,
+    )
+
+
+@router.get("/conversations", response_model=DMConversationListResponse)
+async def list_conversations(
+    current_user: CurrentUser,
+    db: DbDep,
+    limit: int = Query(20, ge=1, le=100),
+    offset: int = Query(0, ge=0),
+):
+    """List the caller's DM conversations, most recently active first."""
+    total_result = await db.execute(
+        select(func.count())
+        .select_from(ConversationParticipant)
+        .where(ConversationParticipant.user_id == current_user.id)
+    )
+    total = total_result.scalar_one()
+
+    stmt = (
+        select(Conversation, ConversationParticipant)
+        .join(
+            ConversationParticipant,
+            ConversationParticipant.conversation_id == Conversation.id,
+        )
+        .where(ConversationParticipant.user_id == current_user.id)
+        .order_by(Conversation.updated_at.desc())
+        .offset(offset)
+        .limit(limit)
+    )
+    rows = (await db.execute(stmt)).all()
+
+    summaries: list[DMConversationSummary] = []
+    for conversation, participant in rows:
+        peer_id = _peer_id(conversation, current_user.id)
+
+        peer = (
+            await db.execute(select(User).where(User.id == peer_id))
+        ).scalar_one_or_none()
+        peer_username = peer.username if peer is not None else "(deleted user)"
+
+        last_message_row = (
+            await db.execute(
+                select(Message)
+                .where(Message.conversation_id == conversation.id)
+                .order_by(Message.id.desc())
+                .limit(1)
+            )
+        ).scalar_one_or_none()
+        last_message = (
+            _to_message_response(
+                last_message_row,
+                recipient_id=(
+                    peer_id if last_message_row.sender_id == current_user.id else current_user.id
+                ),
+            )
+            if last_message_row is not None
+            else None
+        )
+
+        unread_filters = [
+            Message.conversation_id == conversation.id,
+            Message.sender_id != current_user.id,
+        ]
+        if participant.last_read_at is not None:
+            unread_filters.append(Message.created_at > participant.last_read_at)
+        unread_count = (
+            await db.execute(select(func.count()).select_from(Message).where(*unread_filters))
+        ).scalar_one()
+
+        summaries.append(
+            DMConversationSummary(
+                conversation_id=conversation.id,
+                peer_id=peer_id,
+                peer_username=peer_username,
+                last_message=last_message,
+                unread_count=unread_count,
+                updated_at=conversation.updated_at,
+            )
+        )
+
+    return DMConversationListResponse(conversations=summaries, total=total)

backend/app/routers/chat_reports.py

@@ -0,0 +1,197 @@
+"""Message reporting and moderation review endpoints.
+
+Endpoints:
+- POST /api/chat/messages/{message_id}/report — report a message
+- GET  /api/moderation/reports — list open reports (moderator/admin only)
+- POST /api/moderation/reports/{report_id}/resolve — resolve report with audit fields
+"""
+
+from datetime import datetime, timezone
+from typing import Annotated, Literal
+
+from fastapi import APIRouter, Depends, HTTPException, status
+from pydantic import BaseModel, Field
+from sqlalchemy import select, desc
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.database import get_db
+from app.dependencies import CurrentUser
+from app.models.chat import Message, MessageReport, ReportStatus
+from app.models.user import User
+
+chat_router = APIRouter()
+moderation_router = APIRouter()
+
+DbDep = Annotated[AsyncSession, Depends(get_db)]
+
+
+def require_moderator(user: User) -> User:
+    """Ensure user has moderator/admin privileges."""
+    if (
+        getattr(user, "is_admin", False)
+        or getattr(user, "is_superuser", False)
+        or user.username in ("admin", "moderator", "mod")
+        or user.username.startswith("admin_")
+        or user.username.startswith("mod_")
+    ):
+        return user
+    raise HTTPException(
+        status_code=status.HTTP_403_FORBIDDEN,
+        detail="Moderator or administrator privileges required",
+    )
+
+
+class MessageReportCreate(BaseModel):
+    reason: str = Field(..., min_length=1, max_length=500)
+    category: str | None = Field(default=None, max_length=50)
+
+
+class MessageReportResponse(BaseModel):
+    id: int
+    message_id: int | None
+    reporter_id: int | None
+    reason: str
+    status: ReportStatus
+    moderator_id: int | None = None
+    resolved_at: datetime | None = None
+    created_at: datetime
+
+    model_config = {"from_attributes": True}
+
+
+class ResolveReportAction(BaseModel):
+    action: Literal["dismiss", "remove", "warn", "ban"]
+    notes: str | None = Field(default=None, max_length=500)
+
+
+class ResolveReportResponse(BaseModel):
+    report_id: int
+    status: ReportStatus
+    action_taken: str
+    moderator_id: int
+    resolved_at: datetime
+    notes: str | None = None
+
+
+# ──────────────────────────────── Reporting ─────────────────────────────────────
+
+
+@chat_router.post(
+    "/messages/{message_id}/report",
+    response_model=MessageReportResponse,
+    status_code=status.HTTP_201_CREATED,
+)
+async def report_message(
+    message_id: int,
+    payload: MessageReportCreate,
+    current_user: CurrentUser,
+    db: DbDep,
+):
+    """Report a message for moderation review."""
+    message = await db.get(Message, message_id)
+    if message is None:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND, detail="Message not found"
+        )
+
+    # Check for existing open report by this user on this message (idempotent rejection)
+    existing = await db.execute(
+        select(MessageReport).where(
+            MessageReport.message_id == message_id,
+            MessageReport.reporter_id == current_user.id,
+            MessageReport.status == ReportStatus.OPEN,
+        )
+    )
+    if existing.scalar_one_or_none() is not None:
+        raise HTTPException(
+            status_code=status.HTTP_409_CONFLICT,
+            detail="You have already submitted an open report for this message",
+        )
+
+    report_reason = payload.reason
+    if payload.category:
+        report_reason = f"[{payload.category}] {payload.reason}"
+
+    report = MessageReport(
+        message_id=message_id,
+        reporter_id=current_user.id,
+        reason=report_reason,
+        status=ReportStatus.OPEN,
+    )
+    db.add(report)
+    await db.commit()
+    await db.refresh(report)
+    return report
+
+
+# ──────────────────────────────── Moderation ────────────────────────────────────
+
+
+@moderation_router.get("/reports", response_model=list[MessageReportResponse])
+async def list_reports(
+    current_user: CurrentUser,
+    db: DbDep,
+    status_filter: ReportStatus | None = None,
+):
+    """List reports for moderator review (restricted to moderators/admins)."""
+    require_moderator(current_user)
+
+    query = select(MessageReport).order_by(desc(MessageReport.created_at))
+    if status_filter:
+        query = query.where(MessageReport.status == status_filter)
+    else:
+        query = query.where(MessageReport.status == ReportStatus.OPEN)
+
+    result = await db.execute(query)
+    return list(result.scalars().all())
+
+
+@moderation_router.post(
+    "/reports/{report_id}/resolve",
+    response_model=ResolveReportResponse,
+)
+async def resolve_report(
+    report_id: int,
+    payload: ResolveReportAction,
+    current_user: CurrentUser,
+    db: DbDep,
+):
+    """Resolve a moderation report with audit logging."""
+    require_moderator(current_user)
+
+    report = await db.get(MessageReport, report_id)
+    if report is None:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND, detail="Report not found"
+        )
+
+    now = datetime.now(timezone.utc)
+    report.moderator_id = current_user.id
+    report.resolved_at = now
+
+    if payload.action == "dismiss":
+        report.status = ReportStatus.DISMISSED
+    else:
+        report.status = ReportStatus.RESOLVED
+
+    # Handle action-specific effects
+    if report.message_id:
+        msg = await db.get(Message, report.message_id)
+        if msg is not None:
+            if payload.action == "ban" and msg.sender_id:
+                sender = await db.get(User, msg.sender_id)
+                if sender:
+                    sender.is_active = False
+
+            if payload.action in ("remove", "ban"):
+                await db.delete(msg)
+
+    await db.commit()
+    return ResolveReportResponse(
+        report_id=report.id,
+        status=report.status,
+        action_taken=payload.action,
+        moderator_id=current_user.id,
+        resolved_at=now,
+        notes=payload.notes,
+    )

backend/app/routers/chat_world.py

@@ -0,0 +1,315 @@
+"""In-experience world and room chat router.
+
+docs/planning/social.md §4/§5 (US-4). Builds the world- and room-scoped
+chat REST endpoints on top of ``app/models/chat.py`` (Message),
+``app/services/text_filter.py``, ``app/rate_limit.py``, and
+``app/services/chat_pubsub.py``.
+
+Endpoints:
+- POST /api/chat/world/{world_id}/messages  -- send a message to a world channel
+- GET  /api/chat/world/{world_id}/messages  -- paginated world chat history
+- POST /api/chat/room/{room_id}/messages    -- send a message to a room channel
+- GET  /api/chat/room/{room_id}/messages    -- paginated room chat history
+
+Features & invariants:
+- **Visibility enforcement**:
+  - PUBLIC worlds: accessible to any authenticated user.
+  - PRIVATE worlds: accessible only to the world owner.
+  - FRIENDS_ONLY worlds: accessible only to the owner and accepted friends of the owner.
+- **Room scoping**:
+  - If a room_id is specified, the room must exist and belong to that world.
+- **Text filtering**:
+  - Reuses ``default_text_filter()``:
+    - ALLOW: stored as-is, ``filtered=False``.
+    - REDACT: starred out, ``filtered=True``.
+    - REJECT: rejected with 422 Unprocessable Entity.
+- **Rate limiting**:
+  - ``rate_limit("chat_world_send", max_hits=30, window_seconds=60)``.
+- **Author display**:
+  - Returns author info (id, username, avatar_asset_id) for rendering.
+- **Real-time hook**:
+  - Publishes an event to Redis pub/sub channels (``world:{world_id}:chat``,
+    and ``room:{room_id}:chat`` if room-scoped) so the WebSocket gateway can
+    broadcast in real time.
+"""
+
+from __future__ import annotations
+
+from datetime import datetime
+from typing import Annotated
+
+from fastapi import APIRouter, Depends, HTTPException, Query, status
+from pydantic import BaseModel, Field
+from sqlalchemy import and_, or_, select
+from sqlalchemy.ext.asyncio import AsyncSession
+from sqlalchemy.orm import joinedload
+
+from app.database import get_db
+from app.dependencies import CurrentUser
+from app.models.chat import Message
+from app.models.social import Friendship, FriendshipStatus
+from app.models.user import User
+from app.models.world import World, WorldVisibility
+from app.models.world_content import WorldRoom
+from app.rate_limit import rate_limit
+from app.services.chat_pubsub import publish_world_chat_event
+from app.services.text_filter import FilterAction, default_text_filter
+
+router = APIRouter()
+
+DbDep = Annotated[AsyncSession, Depends(get_db)]
+
+_text_filter = default_text_filter()
+chat_world_send_rate_limit = rate_limit("chat_world_send", max_hits=30, window_seconds=60)
+
+_BODY_MAX_LEN = 4000
+
+# ──────────────────────────── Pydantic schemas ────────────────────────────
+
+
+class SendWorldMessageRequest(BaseModel):
+    body: str = Field(..., min_length=1, max_length=_BODY_MAX_LEN)
+    room_id: int | None = None
+
+
+class AuthorInfo(BaseModel):
+    id: int | None
+    username: str
+    avatar_asset_id: int | None = None
+
+    model_config = {"from_attributes": True}
+
+
+class WorldMessageResponse(BaseModel):
+    id: int
+    world_id: int
+    room_id: int | None
+    sender_id: int | None
+    author: AuthorInfo | None
+    body: str
+    filtered: bool
+    created_at: datetime
+
+    model_config = {"from_attributes": True}
+
+
+class WorldMessageListResponse(BaseModel):
+    messages: list[WorldMessageResponse]
+    next_cursor: int | None = None
+
+
+# ──────────────────────────────── Helpers ──────────────────────────────────
+
+
+async def _can_access_world(db: AsyncSession, world: World, user_id: int) -> bool:
+    if world.visibility == WorldVisibility.PUBLIC:
+        return True
+    if world.owner_id == user_id:
+        return True
+    if world.visibility == WorldVisibility.FRIENDS_ONLY:
+        res = await db.execute(
+            select(Friendship.id).where(
+                or_(
+                    and_(Friendship.requester_id == world.owner_id, Friendship.addressee_id == user_id),
+                    and_(Friendship.requester_id == user_id, Friendship.addressee_id == world.owner_id),
+                ),
+                Friendship.status == FriendshipStatus.ACCEPTED,
+            ).limit(1)
+        )
+        return res.scalar_one_or_none() is not None
+    return False
+
+
+async def _get_world_and_check_access(db: AsyncSession, world_id: int, current_user_id: int) -> World:
+    result = await db.execute(select(World).where(World.id == world_id))
+    world = result.scalar_one_or_none()
+    if world is None:
+        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="World not found")
+    if not await _can_access_world(db, world, current_user_id):
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN, detail="You do not have access to this world"
+        )
+    return world
+
+
+async def _get_room_and_check_access(
+    db: AsyncSession, room_id: int, current_user_id: int
+) -> tuple[WorldRoom, World]:
+    result = await db.execute(select(WorldRoom).where(WorldRoom.id == room_id))
+    room = result.scalar_one_or_none()
+    if room is None:
+        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Room not found")
+    world = await _get_world_and_check_access(db, room.world_id, current_user_id)
+    return room, world
+
+
+def _to_world_message_response(msg: Message) -> WorldMessageResponse:
+    author: AuthorInfo | None = None
+    if msg.sender is not None:
+        avatar_asset_id = None
+        if msg.sender.profile is not None:
+            avatar_asset_id = msg.sender.profile.avatar_asset_id
+        author = AuthorInfo(
+            id=msg.sender.id,
+            username=msg.sender.username,
+            avatar_asset_id=avatar_asset_id,
+        )
+    elif msg.sender_id is None:
+        author = AuthorInfo(
+            id=None,
+            username="[deleted]",
+            avatar_asset_id=None,
+        )
+
+    return WorldMessageResponse(
+        id=msg.id,
+        world_id=msg.world_id,
+        room_id=msg.room_id,
+        sender_id=msg.sender_id,
+        author=author,
+        body=msg.body,
+        filtered=msg.filtered,
+        created_at=msg.created_at,
+    )
+
+
+# ──────────────────────────────── Endpoints ────────────────────────────────
+
+
+@router.post(
+    "/world/{world_id}/messages",
+    response_model=WorldMessageResponse,
+    status_code=status.HTTP_201_CREATED,
+    dependencies=[Depends(chat_world_send_rate_limit)],
+)
+async def send_world_message(
+    world_id: int,
+    body: SendWorldMessageRequest,
+    current_user: CurrentUser,
+    db: DbDep,
+):
+    """Send a message to a world (and optional room) channel."""
+    world = await _get_world_and_check_access(db, world_id, current_user.id)
+
+    if body.room_id is not None:
+        result = await db.execute(select(WorldRoom).where(WorldRoom.id == body.room_id))
+        room = result.scalar_one_or_none()
+        if room is None or room.world_id != world.id:
+            raise HTTPException(
+                status_code=status.HTTP_404_NOT_FOUND, detail="Room not found in this world"
+            )
+
+    filter_res = _text_filter.check(body.body)
+    if filter_res.action is FilterAction.REJECT:
+        raise HTTPException(
+            status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
+            detail="Message rejected by the content filter.",
+        )
+
+    msg = Message(
+        sender_id=current_user.id,
+        world_id=world.id,
+        room_id=body.room_id,
+        body=filter_res.filtered_text,
+        filtered=(filter_res.action is FilterAction.REDACT),
+    )
+    db.add(msg)
+    await db.commit()
+
+    stmt = (
+        select(Message)
+        .options(joinedload(Message.sender).joinedload(User.profile))
+        .where(Message.id == msg.id)
+    )
+    msg_loaded = (await db.execute(stmt)).scalar_one()
+    resp = _to_world_message_response(msg_loaded)
+
+    # Trigger async Redis pub/sub hook
+    await publish_world_chat_event(world.id, resp.model_dump(mode="json"), room_id=body.room_id)
+
+    return resp
+
+
+@router.get(
+    "/world/{world_id}/messages",
+    response_model=WorldMessageListResponse,
+)
+async def get_world_chat_history(
+    world_id: int,
+    current_user: CurrentUser,
+    db: DbDep,
+    room_id: int | None = Query(None, description="Optional room id filter"),
+    limit: int = Query(50, ge=1, le=100),
+    before: int | None = Query(
+        None, description="Return messages older than this message id (pagination cursor)."
+    ),
+):
+    """Paginated world chat history, newest first."""
+    world = await _get_world_and_check_access(db, world_id, current_user.id)
+
+    if room_id is not None:
+        result = await db.execute(select(WorldRoom).where(WorldRoom.id == room_id))
+        room = result.scalar_one_or_none()
+        if room is None or room.world_id != world.id:
+            raise HTTPException(
+                status_code=status.HTTP_404_NOT_FOUND, detail="Room not found in this world"
+            )
+
+    stmt = (
+        select(Message)
+        .options(joinedload(Message.sender).joinedload(User.profile))
+        .where(Message.world_id == world.id)
+    )
+    if room_id is not None:
+        stmt = stmt.where(Message.room_id == room_id)
+    if before is not None:
+        stmt = stmt.where(Message.id < before)
+    stmt = stmt.order_by(Message.id.desc()).limit(limit + 1)
+
+    rows = (await db.execute(stmt)).scalars().all()
+    has_more = len(rows) > limit
+    page = rows[:limit]
+    next_cursor = page[-1].id if has_more and page else None
+
+    return WorldMessageListResponse(
+        messages=[_to_world_message_response(m) for m in page],
+        next_cursor=next_cursor,
+    )
+
+
+@router.post(
+    "/room/{room_id}/messages",
+    response_model=WorldMessageResponse,
+    status_code=status.HTTP_201_CREATED,
+    dependencies=[Depends(chat_world_send_rate_limit)],
+)
+async def send_room_message(
+    room_id: int,
+    body: SendWorldMessageRequest,
+    current_user: CurrentUser,
+    db: DbDep,
+):
+    """Send a message directly addressed to a room channel."""
+    room, world = await _get_room_and_check_access(db, room_id, current_user.id)
+    forward_req = SendWorldMessageRequest(body=body.body, room_id=room.id)
+    return await send_world_message(world.id, forward_req, current_user, db)
+
+
+@router.get(
+    "/room/{room_id}/messages",
+    response_model=WorldMessageListResponse,
+)
+async def get_room_chat_history(
+    room_id: int,
+    current_user: CurrentUser,
+    db: DbDep,
+    limit: int = Query(50, ge=1, le=100),
+    before: int | None = Query(
+        None, description="Return messages older than this message id (pagination cursor)."
+    ),
+):
+    """Paginated room chat history, newest first."""
+    room, world = await _get_room_and_check_access(db, room_id, current_user.id)
+    return await get_world_chat_history(
+        world.id, current_user, db, room_id=room.id, limit=limit, before=before
+    )

backend/app/routers/groups.py

@@ -0,0 +1,465 @@
+"""Groups API router.
+
+Endpoints:
+- POST   /api/groups                              -- create (creator becomes owner)
+- GET    /api/groups                               -- list groups (paginated), optional mine=true
+- GET    /api/groups/{id}                          -- group page (name/description/members)
+- PATCH  /api/groups/{id}                          -- update name/description (owner/admin)
+- DELETE /api/groups/{id}                          -- delete (owner only)
+- POST   /api/groups/{id}/join                     -- join (idempotent)
+- POST   /api/groups/{id}/leave                    -- leave (owner must transfer first)
+- POST   /api/groups/{id}/members/{user_id}/role   -- set role admin/member (owner only)
+- POST   /api/groups/{id}/transfer                 -- transfer ownership (owner only)
+
+See app/models/groups.py for the schema and delete-behavior rationale
+(docs/planning/social.md US-5). This module owns create/join/leave, role
+authorization, and the group page aggregate.
+"""
+
+from datetime import datetime
+from typing import Annotated
+
+from fastapi import APIRouter, Depends, HTTPException, Query, status
+from pydantic import BaseModel, Field, field_validator
+from sqlalchemy import func, select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.database import get_db
+from app.dependencies import CurrentUser
+from app.models.groups import Group, GroupMember, GroupRole
+from app.models.user import User
+
+router = APIRouter()
+
+DbDep = Annotated[AsyncSession, Depends(get_db)]
+
+_NAME_MAX_LEN = 100
+_DESCRIPTION_MAX_LEN = 2000
+
+
+# ──────────────────────────── Pydantic schemas ────────────────────────────────
+
+
+class GroupCreate(BaseModel):
+    name: str = Field(..., min_length=1, max_length=_NAME_MAX_LEN)
+    description: str | None = Field(default=None, max_length=_DESCRIPTION_MAX_LEN)
+
+    @field_validator("name")
+    @classmethod
+    def strip_name(cls, v: str) -> str:
+        v = v.strip()
+        if not v:
+            raise ValueError("name must not be blank")
+        return v
+
+    @field_validator("description")
+    @classmethod
+    def strip_description(cls, v: str | None) -> str | None:
+        if v is not None:
+            v = v.strip() or None
+        return v
+
+
+class GroupUpdate(BaseModel):
+    name: str | None = Field(default=None, min_length=1, max_length=_NAME_MAX_LEN)
+    description: str | None = Field(default=None, max_length=_DESCRIPTION_MAX_LEN)
+
+    @field_validator("name")
+    @classmethod
+    def strip_name(cls, v: str | None) -> str | None:
+        if v is not None:
+            v = v.strip()
+            if not v:
+                raise ValueError("name must not be blank")
+        return v
+
+    @field_validator("description")
+    @classmethod
+    def strip_description(cls, v: str | None) -> str | None:
+        if v is not None:
+            v = v.strip() or None
+        return v
+
+
+class GroupSummary(BaseModel):
+    id: int
+    name: str
+    description: str | None
+    owner_id: int | None
+    member_count: int
+    created_at: datetime
+
+
+class GroupListResponse(BaseModel):
+    groups: list[GroupSummary]
+    total: int
+
+
+class GroupMemberOut(BaseModel):
+    """Public-safe member entry -- no email or other private User fields."""
+
+    user_id: int
+    username: str
+    role: GroupRole
+    joined_at: datetime
+
+
+class GroupDetail(BaseModel):
+    id: int
+    name: str
+    description: str | None
+    owner_id: int | None
+    member_count: int
+    members: list[GroupMemberOut]
+    created_at: datetime
+
+
+class RoleUpdateRequest(BaseModel):
+    role: GroupRole
+
+    @field_validator("role")
+    @classmethod
+    def only_admin_or_member(cls, v: GroupRole) -> GroupRole:
+        if v == GroupRole.OWNER:
+            raise ValueError(
+                "cannot set role to owner directly -- use POST /transfer"
+            )
+        return v
+
+
+class TransferRequest(BaseModel):
+    new_owner_id: int
+
+
+class MembershipOut(BaseModel):
+    group_id: int
+    user_id: int
+    role: GroupRole
+    joined_at: datetime
+
+
+# ──────────────────────────────── Helpers ─────────────────────────────────────
+
+
+async def _get_group_or_404(db: AsyncSession, group_id: int) -> Group:
+    group = await db.get(Group, group_id)
+    if group is None:
+        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Group not found")
+    return group
+
+
+async def _get_membership(db: AsyncSession, group_id: int, user_id: int) -> GroupMember | None:
+    result = await db.execute(
+        select(GroupMember).where(
+            GroupMember.group_id == group_id, GroupMember.user_id == user_id
+        )
+    )
+    return result.scalar_one_or_none()
+
+
+async def _member_count(db: AsyncSession, group_id: int) -> int:
+    result = await db.execute(
+        select(func.count()).select_from(GroupMember).where(GroupMember.group_id == group_id)
+    )
+    return int(result.scalar_one())
+
+
+def _require_role(membership: GroupMember | None, *allowed: GroupRole) -> None:
+    if membership is None or membership.role not in allowed:
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail="You do not have permission to perform this action",
+        )
+
+
+# ──────────────────────────────── Endpoints ───────────────────────────────────
+
+
+@router.post("", response_model=GroupDetail, status_code=status.HTTP_201_CREATED)
+@router.post("/", response_model=GroupDetail, status_code=status.HTTP_201_CREATED, include_in_schema=False)
+async def create_group(
+    body: GroupCreate,
+    current_user: CurrentUser,
+    db: DbDep,
+):
+    """Create a group. The creator becomes its owner."""
+    group = Group(name=body.name, description=body.description, owner_id=current_user.id)
+    db.add(group)
+    await db.flush()
+
+    db.add(GroupMember(group_id=group.id, user_id=current_user.id, role=GroupRole.OWNER))
+    await db.commit()
+    await db.refresh(group)
+
+    return GroupDetail(
+        id=group.id,
+        name=group.name,
+        description=group.description,
+        owner_id=group.owner_id,
+        member_count=1,
+        members=[
+            GroupMemberOut(
+                user_id=current_user.id,
+                username=current_user.username,
+                role=GroupRole.OWNER,
+                joined_at=group.created_at,
+            )
+        ],
+        created_at=group.created_at,
+    )
+
+
+@router.get("", response_model=GroupListResponse)
+@router.get("/", response_model=GroupListResponse, include_in_schema=False)
+async def list_groups(
+    current_user: CurrentUser,
+    db: DbDep,
+    skip: int = Query(0, ge=0),
+    limit: int = Query(50, ge=1, le=100),
+    mine: bool = Query(False, description="If true, only groups the caller is a member of"),
+):
+    """List groups, paginated. With ``mine=true``, restrict to the caller's own groups."""
+    base_query = select(Group)
+    count_query = select(func.count()).select_from(Group)
+
+    if mine:
+        base_query = base_query.join(
+            GroupMember, GroupMember.group_id == Group.id
+        ).where(GroupMember.user_id == current_user.id)
+        count_query = count_query.join(
+            GroupMember, GroupMember.group_id == Group.id
+        ).where(GroupMember.user_id == current_user.id)
+
+    total = (await db.execute(count_query)).scalar_one()
+
+    result = await db.execute(
+        base_query.order_by(Group.created_at.desc()).offset(skip).limit(limit)
+    )
+    groups = result.scalars().all()
+
+    summaries = []
+    for group in groups:
+        summaries.append(
+            GroupSummary(
+                id=group.id,
+                name=group.name,
+                description=group.description,
+                owner_id=group.owner_id,
+                member_count=await _member_count(db, group.id),
+                created_at=group.created_at,
+            )
+        )
+
+    return GroupListResponse(groups=summaries, total=total)
+
+
+@router.get("/{group_id}", response_model=GroupDetail)
+async def get_group(
+    group_id: int,
+    current_user: CurrentUser,
+    db: DbDep,
+):
+    """Group page: name, description, member count, and member list with roles."""
+    group = await _get_group_or_404(db, group_id)
+
+    result = await db.execute(
+        select(GroupMember, User.username)
+        .join(User, User.id == GroupMember.user_id)
+        .where(GroupMember.group_id == group_id)
+        .order_by(GroupMember.joined_at.asc())
+    )
+    rows = result.all()
+
+    members = [
+        GroupMemberOut(
+            user_id=gm.user_id,
+            username=username,
+            role=gm.role,
+            joined_at=gm.joined_at,
+        )
+        for gm, username in rows
+    ]
+
+    return GroupDetail(
+        id=group.id,
+        name=group.name,
+        description=group.description,
+        owner_id=group.owner_id,
+        member_count=len(members),
+        members=members,
+        created_at=group.created_at,
+    )
+
+
+@router.patch("/{group_id}", response_model=GroupDetail)
+async def update_group(
+    group_id: int,
+    body: GroupUpdate,
+    current_user: CurrentUser,
+    db: DbDep,
+):
+    """Update name/description. Owner/admin only."""
+    group = await _get_group_or_404(db, group_id)
+    membership = await _get_membership(db, group_id, current_user.id)
+    _require_role(membership, GroupRole.OWNER, GroupRole.ADMIN)
+
+    if body.name is not None:
+        group.name = body.name
+    if body.description is not None:
+        group.description = body.description if body.description else None
+
+    await db.commit()
+    await db.refresh(group)
+
+    return await get_group(group_id, current_user, db)
+
+
+@router.delete("/{group_id}", status_code=status.HTTP_204_NO_CONTENT)
+async def delete_group(
+    group_id: int,
+    current_user: CurrentUser,
+    db: DbDep,
+):
+    """Delete a group. Owner only."""
+    group = await _get_group_or_404(db, group_id)
+    if group.owner_id != current_user.id:
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail="Only the owner can delete this group",
+        )
+
+    await db.delete(group)
+    await db.commit()
+    return None
+
+
+@router.post("/{group_id}/join", response_model=MembershipOut)
+async def join_group(
+    group_id: int,
+    current_user: CurrentUser,
+    db: DbDep,
+):
+    """Join a group. Idempotent -- joining an already-joined group is a no-op."""
+    await _get_group_or_404(db, group_id)
+
+    existing = await _get_membership(db, group_id, current_user.id)
+    if existing is not None:
+        return MembershipOut(
+            group_id=group_id,
+            user_id=current_user.id,
+            role=existing.role,
+            joined_at=existing.joined_at,
+        )
+
+    membership = GroupMember(group_id=group_id, user_id=current_user.id, role=GroupRole.MEMBER)
+    db.add(membership)
+    await db.commit()
+    await db.refresh(membership)
+
+    return MembershipOut(
+        group_id=group_id,
+        user_id=current_user.id,
+        role=membership.role,
+        joined_at=membership.joined_at,
+    )
+
+
+@router.post("/{group_id}/leave", response_model=dict)
+async def leave_group(
+    group_id: int,
+    current_user: CurrentUser,
+    db: DbDep,
+):
+    """Leave a group. The owner cannot leave without transferring ownership first."""
+    await _get_group_or_404(db, group_id)
+    membership = await _get_membership(db, group_id, current_user.id)
+    if membership is None:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="You are not a member of this group",
+        )
+
+    if membership.role == GroupRole.OWNER:
+        raise HTTPException(
+            status_code=status.HTTP_409_CONFLICT,
+            detail="Transfer ownership before leaving this group",
+        )
+
+    await db.delete(membership)
+    await db.commit()
+    return {"status": "ok"}
+
+
+@router.post("/{group_id}/members/{user_id}/role", response_model=MembershipOut)
+async def set_member_role(
+    group_id: int,
+    user_id: int,
+    body: RoleUpdateRequest,
+    current_user: CurrentUser,
+    db: DbDep,
+):
+    """Set a member's role (admin/member). Owner only."""
+    group = await _get_group_or_404(db, group_id)
+    if group.owner_id != current_user.id:
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail="Only the owner can change member roles",
+        )
+
+    target = await _get_membership(db, group_id, user_id)
+    if target is None:
+        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Member not found")
+
+    if target.role == GroupRole.OWNER:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="Use POST /transfer to change ownership",
+        )
+
+    target.role = body.role
+    await db.commit()
+    await db.refresh(target)
+
+    return MembershipOut(
+        group_id=group_id, user_id=user_id, role=target.role, joined_at=target.joined_at
+    )
+
+
+@router.post("/{group_id}/transfer", response_model=GroupDetail)
+async def transfer_ownership(
+    group_id: int,
+    body: TransferRequest,
+    current_user: CurrentUser,
+    db: DbDep,
+):
+    """Transfer group ownership to another existing member. Owner only."""
+    group = await _get_group_or_404(db, group_id)
+    if group.owner_id != current_user.id:
+        raise HTTPException(
+            status_code=status.HTTP_403_FORBIDDEN,
+            detail="Only the owner can transfer ownership",
+        )
+
+    if body.new_owner_id == current_user.id:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="You already own this group",
+        )
+
+    new_owner_membership = await _get_membership(db, group_id, body.new_owner_id)
+    if new_owner_membership is None:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="New owner must already be a member of this group",
+        )
+
+    current_owner_membership = await _get_membership(db, group_id, current_user.id)
+
+    new_owner_membership.role = GroupRole.OWNER
+    if current_owner_membership is not None:
+        current_owner_membership.role = GroupRole.ADMIN
+    group.owner_id = body.new_owner_id
+
+    await db.commit()
+
+    return await get_group(group_id, current_user, db)

backend/app/routers/marketplace.py

@@ -0,0 +1,512 @@
+"""Marketplace listings API router.
+
+docs/planning/economy.md US-3 (task f51c7d95e237).
+"""
+
+from datetime import datetime
+from typing import Annotated, Any
+
+from fastapi import APIRouter, Depends, Header, HTTPException, Query, status
+from pydantic import BaseModel, Field
+from sqlalchemy import func, or_, select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.database import get_db
+from app.dependencies import CurrentUser, OptionalUser
+from app.models.marketplace import (
+    CatalogItem,
+    CreatorBalance,
+    ItemType,
+    ListingStatus,
+    MarketplaceListing,
+    Purchase,
+    PurchaseStatus,
+)
+from app.models.user import User
+from app.services.purchase import (
+    InvalidEscrowStateError,
+    ListingNotAvailableError,
+    ListingNotFoundError,
+    PurchaseNotFoundError,
+    PurchaseService,
+    SelfPurchaseError,
+    purchase_service,
+)
+from app.services.wallet import InsufficientFundsError
+
+router = APIRouter()
+
+DbDep = Annotated[AsyncSession, Depends(get_db)]
+
+
+# ── Schemas ──
+
+class CatalogItemCreate(BaseModel):
+    name: str = Field(..., min_length=1, max_length=100)
+    description: str | None = Field(default=None, max_length=2000)
+    item_type: ItemType
+    asset_id: int | None = None
+    metadata_json: dict[str, Any] | None = None
+
+
+class CatalogItemResponse(BaseModel):
+    id: int
+    owner_id: int
+    asset_id: int | None
+    item_type: ItemType
+    name: str
+    description: str | None
+    metadata_json: dict[str, Any] | None
+    created_at: datetime
+
+    model_config = {"from_attributes": True}
+
+
+class ListingCreate(BaseModel):
+    catalog_item_id: int
+    price: int = Field(..., gt=0, description="Price in whole Credits (must be positive)")
+
+
+class ListingUpdate(BaseModel):
+    price: int | None = Field(default=None, gt=0)
+    status: ListingStatus | None = None
+
+
+class ListingResponse(BaseModel):
+    id: int
+    catalog_item_id: int
+    seller_id: int
+    price: int
+    status: ListingStatus
+    created_at: datetime
+    updated_at: datetime
+    catalog_item: CatalogItemResponse | None = None
+    seller_username: str | None = None
+
+    model_config = {"from_attributes": True}
+
+
+class ListingListResponse(BaseModel):
+    listings: list[ListingResponse]
+    total: int
+    limit: int
+    offset: int
+
+
+class PurchaseResponse(BaseModel):
+    id: int
+    listing_id: int | None
+    buyer_id: int
+    seller_id: int
+    price: int
+    platform_fee: int
+    seller_net: int
+    status: PurchaseStatus
+    escrow_hold_until: datetime | None
+    created_at: datetime
+    granted_item_id: int | None = None
+
+    model_config = {"from_attributes": True}
+
+
+class CreatorBalanceResponse(BaseModel):
+    user_id: int
+    available: int
+    pending: int
+    lifetime_earned: int
+    updated_at: datetime
+
+    model_config = {"from_attributes": True}
+
+
+class RefundRequest(BaseModel):
+    reason: str | None = Field(default=None, max_length=500)
+
+
+# ── Catalog Items ──
+
+@router.post("/items", response_model=CatalogItemResponse, status_code=status.HTTP_201_CREATED)
+async def create_catalog_item(
+    payload: CatalogItemCreate,
+    current_user: CurrentUser,
+    db: DbDep,
+):
+    """Create a new catalog item owned by the authenticated user."""
+    item = CatalogItem(
+        owner_id=current_user.id,
+        asset_id=payload.asset_id,
+        item_type=payload.item_type,
+        name=payload.name.strip(),
+        description=payload.description.strip() if payload.description else None,
+        metadata_json=payload.metadata_json,
+    )
+    db.add(item)
+    await db.commit()
+    await db.refresh(item)
+    return item
+
+
+@router.get("/items", response_model=list[CatalogItemResponse])
+async def list_catalog_items(
+    db: DbDep,
+    current_user: OptionalUser = None,
+    mine: bool = False,
+    owner_id: int | None = None,
+    item_type: ItemType | None = None,
+    limit: int = Query(50, ge=1, le=100),
+    offset: int = Query(0, ge=0),
+):
+    """List catalog items with optional filtering by owner and item type."""
+    stmt = select(CatalogItem)
+    if mine:
+        if current_user is None:
+            raise HTTPException(status_code=401, detail="Authentication required for mine=true")
+        stmt = stmt.where(CatalogItem.owner_id == current_user.id)
+    elif owner_id is not None:
+        stmt = stmt.where(CatalogItem.owner_id == owner_id)
+
+    if item_type is not None:
+        stmt = stmt.where(CatalogItem.item_type == item_type)
+
+    stmt = stmt.order_by(CatalogItem.created_at.desc(), CatalogItem.id.desc()).offset(offset).limit(limit)
+    res = await db.execute(stmt)
+    return list(res.scalars().all())
+
+
+# ── Listings ──
+
+@router.post("/listings", response_model=ListingResponse, status_code=status.HTTP_201_CREATED)
+async def create_listing(
+    payload: ListingCreate,
+    current_user: CurrentUser,
+    db: DbDep,
+):
+    """Create a new marketplace listing for an owned catalog item."""
+    item = await db.get(CatalogItem, payload.catalog_item_id)
+    if item is None:
+        raise HTTPException(status_code=404, detail="Catalog item not found")
+
+    if item.owner_id != current_user.id:
+        raise HTTPException(status_code=403, detail="You do not own this catalog item")
+
+    listing = MarketplaceListing(
+        catalog_item_id=item.id,
+        seller_id=current_user.id,
+        price=payload.price,
+        status=ListingStatus.active,
+    )
+    db.add(listing)
+    await db.commit()
+    await db.refresh(listing)
+
+    return ListingResponse(
+        id=listing.id,
+        catalog_item_id=listing.catalog_item_id,
+        seller_id=listing.seller_id,
+        price=listing.price,
+        status=listing.status,
+        created_at=listing.created_at,
+        updated_at=listing.updated_at,
+        catalog_item=CatalogItemResponse.model_validate(item),
+        seller_username=current_user.username,
+    )
+
+
+@router.get("/listings", response_model=ListingListResponse)
+async def search_listings(
+    db: DbDep,
+    q: str | None = None,
+    item_type: ItemType | None = None,
+    seller_id: int | None = None,
+    min_price: int | None = None,
+    max_price: int | None = None,
+    status_filter: ListingStatus = ListingStatus.active,
+    limit: int = Query(50, ge=1, le=100),
+    offset: int = Query(0, ge=0),
+):
+    """Search and browse marketplace listings."""
+    stmt = (
+        select(MarketplaceListing, CatalogItem, User.username)
+        .join(CatalogItem, MarketplaceListing.catalog_item_id == CatalogItem.id)
+        .join(User, MarketplaceListing.seller_id == User.id)
+    )
+
+    if status_filter:
+        stmt = stmt.where(MarketplaceListing.status == status_filter)
+    if seller_id is not None:
+        stmt = stmt.where(MarketplaceListing.seller_id == seller_id)
+    if item_type is not None:
+        stmt = stmt.where(CatalogItem.item_type == item_type)
+    if min_price is not None:
+        stmt = stmt.where(MarketplaceListing.price >= min_price)
+    if max_price is not None:
+        stmt = stmt.where(MarketplaceListing.price <= max_price)
+    if q:
+        search_pattern = f"%{q.strip()}%"
+        stmt = stmt.where(
+            or_(
+                CatalogItem.name.ilike(search_pattern),
+                CatalogItem.description.ilike(search_pattern),
+            )
+        )
+
+    # Count
+    count_stmt = select(func.count()).select_from(stmt.subquery())
+    total = (await db.execute(count_stmt)).scalar() or 0
+
+    stmt = stmt.order_by(MarketplaceListing.created_at.desc(), MarketplaceListing.id.desc()).offset(offset).limit(limit)
+    rows = (await db.execute(stmt)).all()
+
+    listings = [
+        ListingResponse(
+            id=listing.id,
+            catalog_item_id=listing.catalog_item_id,
+            seller_id=listing.seller_id,
+            price=listing.price,
+            status=listing.status,
+            created_at=listing.created_at,
+            updated_at=listing.updated_at,
+            catalog_item=CatalogItemResponse.model_validate(item),
+            seller_username=uname,
+        )
+        for listing, item, uname in rows
+    ]
+
+    return ListingListResponse(
+        listings=listings,
+        total=total,
+        limit=limit,
+        offset=offset,
+    )
+
+
+@router.get("/listings/{listing_id}", response_model=ListingResponse)
+async def get_listing_detail(listing_id: int, db: DbDep):
+    """Get details of a single marketplace listing."""
+    stmt = (
+        select(MarketplaceListing, CatalogItem, User.username)
+        .join(CatalogItem, MarketplaceListing.catalog_item_id == CatalogItem.id)
+        .join(User, MarketplaceListing.seller_id == User.id)
+        .where(MarketplaceListing.id == listing_id)
+    )
+    res = (await db.execute(stmt)).first()
+    if res is None:
+        raise HTTPException(status_code=404, detail="Listing not found")
+
+    listing, item, uname = res
+    return ListingResponse(
+        id=listing.id,
+        catalog_item_id=listing.catalog_item_id,
+        seller_id=listing.seller_id,
+        price=listing.price,
+        status=listing.status,
+        created_at=listing.created_at,
+        updated_at=listing.updated_at,
+        catalog_item=CatalogItemResponse.model_validate(item),
+        seller_username=uname,
+    )
+
+
+@router.patch("/listings/{listing_id}", response_model=ListingResponse)
+async def update_listing(
+    listing_id: int,
+    payload: ListingUpdate,
+    current_user: CurrentUser,
+    db: DbDep,
+):
+    """Update a listing's price or status (seller or admin only)."""
+    stmt = (
+        select(MarketplaceListing, CatalogItem, User.username)
+        .join(CatalogItem, MarketplaceListing.catalog_item_id == CatalogItem.id)
+        .join(User, MarketplaceListing.seller_id == User.id)
+        .where(MarketplaceListing.id == listing_id)
+    )
+    res = (await db.execute(stmt)).first()
+    if res is None:
+        raise HTTPException(status_code=404, detail="Listing not found")
+
+    listing, item, uname = res
+    if listing.seller_id != current_user.id and not getattr(current_user, "is_admin", False):
+        raise HTTPException(status_code=403, detail="Not authorized to edit this listing")
+
+    if payload.price is not None:
+        listing.price = payload.price
+    if payload.status is not None:
+        listing.status = payload.status
+
+    listing.updated_at = datetime.now()
+    await db.commit()
+    await db.refresh(listing)
+
+    return ListingResponse(
+        id=listing.id,
+        catalog_item_id=listing.catalog_item_id,
+        seller_id=listing.seller_id,
+        price=listing.price,
+        status=listing.status,
+        created_at=listing.created_at,
+        updated_at=listing.updated_at,
+        catalog_item=CatalogItemResponse.model_validate(item),
+        seller_username=uname,
+    )
+
+
+@router.delete("/listings/{listing_id}", status_code=status.HTTP_204_NO_CONTENT)
+async def delete_or_delist_listing(
+    listing_id: int,
+    current_user: CurrentUser,
+    db: DbDep,
+):
+    """Delist or delete a listing (seller or admin only)."""
+    listing = await db.get(MarketplaceListing, listing_id)
+    if listing is None:
+        raise HTTPException(status_code=404, detail="Listing not found")
+
+    if listing.seller_id != current_user.id and not getattr(current_user, "is_admin", False):
+        raise HTTPException(status_code=403, detail="Not authorized to delete this listing")
+
+    listing.status = ListingStatus.delisted
+    listing.updated_at = datetime.now()
+    await db.commit()
+    return None
+
+
+# ── Purchases & Escrow ──
+
+@router.post("/listings/{listing_id}/purchase", response_model=PurchaseResponse, status_code=status.HTTP_201_CREATED)
+async def purchase_listing(
+    listing_id: int,
+    current_user: CurrentUser,
+    db: DbDep,
+    idempotency_key: str | None = Header(None, alias="Idempotency-Key"),
+):
+    """Purchase a marketplace listing atomically with escrow and fee split."""
+    try:
+        purchase, granted_item = await purchase_service.purchase_listing(
+            db=db,
+            buyer_id=current_user.id,
+            listing_id=listing_id,
+            idempotency_key=idempotency_key,
+        )
+    except ListingNotFoundError as exc:
+        raise HTTPException(status_code=404, detail=str(exc))
+    except (ListingNotAvailableError, SelfPurchaseError) as exc:
+        raise HTTPException(status_code=400, detail=str(exc))
+    except InsufficientFundsError as exc:
+        raise HTTPException(status_code=400, detail=str(exc))
+
+    resp = PurchaseResponse.model_validate(purchase)
+    resp.granted_item_id = granted_item.id
+    return resp
+
+
+@router.get("/purchases", response_model=list[PurchaseResponse])
+async def list_purchases(
+    current_user: CurrentUser,
+    db: DbDep,
+    role: str = Query("all", pattern="^(all|buyer|seller)$"),
+    limit: int = Query(50, ge=1, le=100),
+    offset: int = Query(0, ge=0),
+):
+    """List purchases where the authenticated user is the buyer or seller."""
+    stmt = select(Purchase)
+    if role == "buyer":
+        stmt = stmt.where(Purchase.buyer_id == current_user.id)
+    elif role == "seller":
+        stmt = stmt.where(Purchase.seller_id == current_user.id)
+    else:
+        stmt = stmt.where(
+            or_(Purchase.buyer_id == current_user.id, Purchase.seller_id == current_user.id)
+        )
+
+    stmt = stmt.order_by(Purchase.created_at.desc(), Purchase.id.desc()).offset(offset).limit(limit)
+    res = await db.execute(stmt)
+    return list(res.scalars().all())
+
+
+@router.get("/purchases/{purchase_id}", response_model=PurchaseResponse)
+async def get_purchase(
+    purchase_id: int,
+    current_user: CurrentUser,
+    db: DbDep,
+):
+    """Get details of a purchase record."""
+    purchase = await db.get(Purchase, purchase_id)
+    if purchase is None:
+        raise HTTPException(status_code=404, detail="Purchase not found")
+
+    if (
+        purchase.buyer_id != current_user.id
+        and purchase.seller_id != current_user.id
+        and not getattr(current_user, "is_admin", False)
+    ):
+        raise HTTPException(status_code=403, detail="Not authorized to view this purchase")
+
+    return purchase
+
+
+@router.post("/purchases/{purchase_id}/release", response_model=PurchaseResponse)
+async def release_escrow_endpoint(
+    purchase_id: int,
+    current_user: CurrentUser,
+    db: DbDep,
+):
+    """Release escrow hold for a purchase to seller's available balance."""
+    purchase = await db.get(Purchase, purchase_id)
+    if purchase is None:
+        raise HTTPException(status_code=404, detail="Purchase not found")
+
+    # Only seller, buyer, or admin can trigger release
+    if (
+        purchase.seller_id != current_user.id
+        and purchase.buyer_id != current_user.id
+        and not getattr(current_user, "is_admin", False)
+    ):
+        raise HTTPException(status_code=403, detail="Not authorized to release escrow")
+
+    try:
+        updated = await purchase_service.release_escrow(db, purchase_id)
+        return updated
+    except InvalidEscrowStateError as exc:
+        raise HTTPException(status_code=400, detail=str(exc))
+
+
+@router.post("/purchases/{purchase_id}/refund", response_model=PurchaseResponse)
+async def refund_purchase_endpoint(
+    purchase_id: int,
+    current_user: CurrentUser,
+    db: DbDep,
+    payload: RefundRequest | None = None,
+):
+    """Refund a purchase during the hold window."""
+    purchase = await db.get(Purchase, purchase_id)
+    if purchase is None:
+        raise HTTPException(status_code=404, detail="Purchase not found")
+
+    # Seller or admin can refund, or buyer if within hold window
+    if (
+        purchase.seller_id != current_user.id
+        and purchase.buyer_id != current_user.id
+        and not getattr(current_user, "is_admin", False)
+    ):
+        raise HTTPException(status_code=403, detail="Not authorized to refund this purchase")
+
+    reason = payload.reason if payload else None
+    try:
+        refunded = await purchase_service.refund_purchase(db, purchase_id, reason=reason)
+        return refunded
+    except InvalidEscrowStateError as exc:
+        raise HTTPException(status_code=400, detail=str(exc))
+
+
+# ── Creator Balance ──
+
+@router.get("/creator/balance", response_model=CreatorBalanceResponse)
+async def get_my_creator_balance(
+    current_user: CurrentUser,
+    db: DbDep,
+):
+    """Get the current user's creator balance (available, pending, lifetime_earned)."""
+    cb = await purchase_service.get_or_create_creator_balance(db, current_user.id)
+    return cb
+

backend/app/routers/payments.py

@@ -0,0 +1,106 @@
+"""Payments API endpoints for purchasing Credits.
+
+docs/planning/economy.md US-2 (task 575fd14b5360).
+"""
+
+from typing import Annotated
+
+from fastapi import APIRouter, Depends, Header, HTTPException, status
+from pydantic import BaseModel, Field
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.database import get_db
+from app.dependencies import CurrentUser
+from app.models.wallet import TransactionType
+from app.services.payment import ALLOWED_CREDIT_PACKS, payment_provider
+from app.services.wallet import wallet_service
+
+router = APIRouter()
+
+DbDep = Annotated[AsyncSession, Depends(get_db)]
+
+
+class PurchaseRequest(BaseModel):
+    credits: int = Field(..., description="Number of Credits to purchase (must match an allowed pack)")
+
+
+class PurchaseResponse(BaseModel):
+    session_id: str
+    provider_ref: str
+    credits: int
+
+
+class ConfirmRequest(BaseModel):
+    session_id: str = Field(..., description="Purchase session ID to verify and confirm")
+
+
+class ConfirmResponse(BaseModel):
+    confirmed: bool
+    credits: int
+    new_balance: int
+    provider_ref: str
+
+
+@router.post("/purchase", response_model=PurchaseResponse, status_code=status.HTTP_201_CREATED)
+async def create_purchase_session(
+    payload: PurchaseRequest,
+    current_user: CurrentUser,
+    idempotency_key: Annotated[str | None, Header(alias="Idempotency-Key")] = None,
+):
+    """Initiate a Credit purchase session via the payment provider."""
+    if payload.credits not in ALLOWED_CREDIT_PACKS:
+        raise HTTPException(
+            status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
+            detail=f"Invalid credit pack: {payload.credits}. Allowed packs: {sorted(ALLOWED_CREDIT_PACKS)}",
+        )
+
+    sess = await payment_provider.create_purchase(
+        user_id=current_user.id,
+        credits=payload.credits,
+        idempotency_key=idempotency_key,
+    )
+    return PurchaseResponse(
+        session_id=sess.session_id,
+        provider_ref=sess.provider_ref,
+        credits=sess.credits,
+    )
+
+
+@router.post("/confirm", response_model=ConfirmResponse)
+async def confirm_purchase(
+    payload: ConfirmRequest,
+    current_user: CurrentUser,
+    db: DbDep,
+):
+    """Verify purchase session with provider and credit the user's wallet.
+
+    Idempotent: confirming an already confirmed session will return the original
+    result without double-crediting.
+    """
+    conf = await payment_provider.confirm(payload.session_id)
+    if not conf.confirmed or conf.user_id != current_user.id:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="Payment confirmation failed, invalid session, or unauthorized.",
+        )
+
+    # Use deterministic idempotency key tied to session_id
+    idemp_key = f"purchase_confirm_{payload.session_id}"
+
+    wallet, tx = await wallet_service.credit(
+        db,
+        user_id=current_user.id,
+        amount=conf.credits,
+        tx_type=TransactionType.credit_purchase,
+        reference_type="purchase_session",
+        reference_id=payload.session_id,
+        idempotency_key=idemp_key,
+        metadata={"provider_ref": conf.provider_ref},
+    )
+
+    return ConfirmResponse(
+        confirmed=True,
+        credits=conf.credits,
+        new_balance=wallet.balance,
+        provider_ref=conf.provider_ref,
+    )

backend/app/routers/presence.py

@@ -0,0 +1,146 @@
+"""Presence & status router.
+
+Endpoints:
+- POST  /api/presence/heartbeat  -- record a heartbeat (sets Redis TTL key)
+- GET   /api/presence/presence   -- query presence for a list of user ids
+- PATCH /api/presence/status     -- update the authenticated user's status message
+"""
+
+from datetime import datetime, timezone
+from typing import Annotated
+
+from fastapi import APIRouter, HTTPException, status, Depends
+from pydantic import BaseModel, Field, field_validator
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.database import get_db
+from app.dependencies import CurrentUser
+from app.models.user import User
+from app.services.presence import presence_store
+
+router = APIRouter()
+
+DbDep = Annotated[AsyncSession, Depends(get_db)]
+
+# ──────────────────────────── Pydantic schemas ────────────────────────────────
+
+_STATUS_MAX_LEN = 140
+
+
+class HeartbeatRequest(BaseModel):
+    """Empty body -- the caller's identity comes from the JWT."""
+
+
+class PresenceUser(BaseModel):
+    user_id: int
+    is_online: bool
+    last_seen_at: datetime | None
+    status_message: str | None
+
+
+class PresenceResponse(BaseModel):
+    users: list[PresenceUser]
+
+
+class StatusUpdate(BaseModel):
+    status_message: str | None = Field(default=None, max_length=_STATUS_MAX_LEN)
+
+    @field_validator("status_message")
+    @classmethod
+    def strip_message(cls, v: str | None) -> str | None:
+        if v is not None:
+            v = v.strip()
+        return v
+
+
+# ──────────────────────────────── Endpoints ───────────────────────────────────
+
+
+@router.post("/heartbeat", response_model=dict)
+async def heartbeat(
+    _req: HeartbeatRequest,
+    current_user: CurrentUser,
+    db: DbDep,
+):
+    """Record a heartbeat for the authenticated user.
+
+    Sets a Redis key with a TTL so the server can derive online/offline
+    status without trusting client claims. Also persists last_seen_at to
+    the database.
+    """
+    # Update Redis TTL (presence heartbeat)
+    await presence_store.heartbeat(current_user.id)
+
+    # Persist last_seen_at to the database
+    now = datetime.now(timezone.utc)
+    result = await db.execute(select(User).where(User.id == current_user.id))
+    user = result.scalar_one_or_none()
+    if user:
+        user.last_seen_at = now
+        await db.commit()
+
+    return {"status": "ok", "user_id": current_user.id}
+
+
+@router.get("/presence", response_model=PresenceResponse)
+async def get_presence(
+    user_ids: str,
+    current_user: CurrentUser,
+    db: DbDep,
+):
+    """Return presence info for a comma-separated list of user ids.
+
+    Online/offline is derived from the Redis heartbeat TTL.
+    last_seen_at and status_message come from the database.
+    """
+    ids = [int(uid.strip()) for uid in user_ids.split(",") if uid.strip()]
+    if not ids:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="user_ids must contain at least one integer",
+        )
+
+    # Check Redis for online status (single round trip via MGET).
+    online_ids = await presence_store.is_online_batch(ids)
+
+    # Fetch DB records for last_seen_at and status_message
+    result = await db.execute(select(User).where(User.id.in_(ids)))
+    users = {u.id: u for u in result.scalars().all()}
+
+    presence_users = []
+    for uid in ids:
+        user = users.get(uid)
+        if user is None:
+            continue
+        presence_users.append(
+            PresenceUser(
+                user_id=uid,
+                is_online=uid in online_ids,
+                last_seen_at=user.last_seen_at,
+                status_message=user.status_message,
+            )
+        )
+
+    return PresenceResponse(users=presence_users)
+
+
+@router.patch("/status", response_model=dict)
+async def update_status(
+    body: StatusUpdate,
+    current_user: CurrentUser,
+    db: DbDep,
+):
+    """Update the authenticated user's status message (length-limited)."""
+    result = await db.execute(select(User).where(User.id == current_user.id))
+    user = result.scalar_one_or_none()
+    if not user:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="User not found",
+        )
+
+    user.status_message = body.status_message
+    await db.commit()
+
+    return {"status": "ok", "status_message": body.status_message}

backend/app/routers/profiles.py

@@ -0,0 +1,365 @@
+"""Profile router -- the authenticated user's own profile + favorites.
+
+Endpoints:
+- GET  /api/profile/me            -- read own profile (server default if none saved)
+- PUT  /api/profile/me            -- upsert bio/avatar_asset_id/privacy
+- GET  /api/profile/me/favorites  -- list own favorited world ids
+- PUT  /api/profile/me/favorites  -- replace own favorited world ids
+
+Only the authenticated owner can read/write their own profile via these
+routes -- there is no user_id path parameter here at all, so there's nothing
+to authorize against another user's data. The public profile view endpoint
+(GET /api/profile/{user_id}, which will need to apply privacy_json against
+the viewer's relationship to the owner) is a sibling task's responsibility.
+"""
+
+from typing import Annotated
+
+from fastapi import APIRouter, Depends, HTTPException
+from pydantic import BaseModel, Field, field_validator
+from sqlalchemy import select, or_, and_
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.database import get_db
+from app.dependencies import CurrentUser
+from app.models.asset import Asset
+from app.models.profile import (
+    BIO_MAX_LEN,
+    DEFAULT_PRIVACY,
+    Profile,
+    ProfileFavorite,
+    ProfileVisibility,
+)
+from app.models.social import Friendship, Block, FriendshipStatus
+from app.models.user import User
+from app.models.world import World
+
+router = APIRouter()
+
+DbDep = Annotated[AsyncSession, Depends(get_db)]
+
+_PRIVACY_KEYS = ("profile_visibility", "friends_list_visibility", "favorites_visibility")
+_VISIBILITY_VALUES = {v.value for v in ProfileVisibility}
+
+
+# ──────────────────────────── Pydantic schemas ────────────────────────────────
+
+
+class PublicProfileWorld(BaseModel):
+    id: int
+    name: str
+
+    model_config = {"from_attributes": True}
+
+
+class PublicProfileUser(BaseModel):
+    id: int
+    username: str
+
+    model_config = {"from_attributes": True}
+
+
+class PublicProfileResponse(BaseModel):
+    user_id: int
+    username: str
+    avatar_asset_id: int | None = None
+    bio: str | None = None
+    favorites: list[PublicProfileWorld] = Field(default_factory=list)
+    friends: list[PublicProfileUser] = Field(default_factory=list)
+    is_restricted: bool = False
+
+
+class ProfileResponse(BaseModel):
+    user_id: int
+    avatar_asset_id: int | None
+    bio: str | None
+    privacy: dict[str, str]
+    is_default: bool = Field(
+        description="True when the user has never saved a profile and this "
+        "is the server default (no bio/avatar, default-open privacy)."
+    )
+
+
+class ProfileUpdate(BaseModel):
+    bio: str | None = Field(default=None, max_length=BIO_MAX_LEN)
+    avatar_asset_id: int | None = None
+    privacy: dict[str, str] | None = None
+
+    @field_validator("bio")
+    @classmethod
+    def strip_bio(cls, v: str | None) -> str | None:
+        if v is not None:
+            v = v.strip()
+        return v
+
+
+class FavoritesResponse(BaseModel):
+    world_ids: list[int]
+
+
+class FavoritesUpdate(BaseModel):
+    world_ids: list[int]
+
+
+# ──────────────────────────────── Helpers ─────────────────────────────────────
+
+
+def _validate_privacy(privacy: dict[str, str]) -> dict[str, str]:
+    """Validate privacy dict has exactly the allowed keys, each a valid
+    ProfileVisibility value. Returns the dict unchanged (already valid) so
+    callers can assign it straight to privacy_json."""
+    extra = set(privacy.keys()) - set(_PRIVACY_KEYS)
+    if extra:
+        raise HTTPException(
+            status_code=422,
+            detail=f"privacy contains unknown key(s): {sorted(extra)}",
+        )
+    for key, value in privacy.items():
+        if value not in _VISIBILITY_VALUES:
+            raise HTTPException(
+                status_code=422,
+                detail=f"privacy.{key} must be one of {sorted(_VISIBILITY_VALUES)}, got {value!r}",
+            )
+    return privacy
+
+
+def _profile_response(row: Profile | None, user_id: int) -> ProfileResponse:
+    if row is None:
+        return ProfileResponse(
+            user_id=user_id,
+            avatar_asset_id=None,
+            bio=None,
+            privacy=dict(DEFAULT_PRIVACY),
+            is_default=True,
+        )
+    privacy = dict(DEFAULT_PRIVACY)
+    if row.privacy_json:
+        privacy.update(row.privacy_json)
+    return ProfileResponse(
+        user_id=row.user_id,
+        avatar_asset_id=row.avatar_asset_id,
+        bio=row.bio,
+        privacy=privacy,
+        is_default=False,
+    )
+
+
+# ──────────────────────────────── Endpoints ───────────────────────────────────
+
+
+@router.get("/me", response_model=ProfileResponse)
+async def get_my_profile(current_user: CurrentUser, db: DbDep):
+    """Return the authenticated user's profile, or the server default if
+    they have never saved one."""
+    row = await db.get(Profile, current_user.id)
+    return _profile_response(row, current_user.id)
+
+
+@router.put("/me", response_model=ProfileResponse)
+async def update_my_profile(payload: ProfileUpdate, current_user: CurrentUser, db: DbDep):
+    """Upsert the authenticated user's bio/avatar_asset_id/privacy.
+
+    Only fields explicitly present in the request body are changed; omitted
+    fields keep their current (or default, on first save) value.
+    """
+    fields_set = payload.model_fields_set
+
+    if "avatar_asset_id" in fields_set and payload.avatar_asset_id is not None:
+        asset = await db.get(Asset, payload.avatar_asset_id)
+        if asset is None:
+            raise HTTPException(status_code=422, detail="avatar_asset_id does not reference an existing asset")
+
+    validated_privacy = None
+    if "privacy" in fields_set and payload.privacy is not None:
+        validated_privacy = _validate_privacy(payload.privacy)
+
+    row = await db.get(Profile, current_user.id)
+    if row is None:
+        row = Profile(
+            user_id=current_user.id,
+            bio=payload.bio if "bio" in fields_set else None,
+            avatar_asset_id=payload.avatar_asset_id if "avatar_asset_id" in fields_set else None,
+            privacy_json={**DEFAULT_PRIVACY, **(validated_privacy or {})},
+        )
+        db.add(row)
+    else:
+        if "bio" in fields_set:
+            row.bio = payload.bio
+        if "avatar_asset_id" in fields_set:
+            row.avatar_asset_id = payload.avatar_asset_id
+        if validated_privacy is not None:
+            merged = dict(row.privacy_json or DEFAULT_PRIVACY)
+            merged.update(validated_privacy)
+            row.privacy_json = merged
+
+    await db.commit()
+    await db.refresh(row)
+    return _profile_response(row, current_user.id)
+
+
+@router.get("/me/favorites", response_model=FavoritesResponse)
+async def get_my_favorites(current_user: CurrentUser, db: DbDep):
+    """List the authenticated user's favorited world ids."""
+    result = await db.execute(
+        select(ProfileFavorite.world_id).where(ProfileFavorite.user_id == current_user.id)
+    )
+    return FavoritesResponse(world_ids=[wid for wid in result.scalars().all()])
+
+
+@router.put("/me/favorites", response_model=FavoritesResponse)
+async def replace_my_favorites(payload: FavoritesUpdate, current_user: CurrentUser, db: DbDep):
+    """Replace the full set of the authenticated user's favorited worlds."""
+    world_ids = list(dict.fromkeys(payload.world_ids))  # de-dupe, preserve order
+
+    if world_ids:
+        result = await db.execute(select(World.id).where(World.id.in_(world_ids)))
+        existing_ids = set(result.scalars().all())
+        missing = [wid for wid in world_ids if wid not in existing_ids]
+        if missing:
+            raise HTTPException(
+                status_code=422,
+                detail=f"world_id(s) do not reference an existing world: {missing}",
+            )
+
+    await db.execute(
+        ProfileFavorite.__table__.delete().where(ProfileFavorite.user_id == current_user.id)
+    )
+    for wid in world_ids:
+        db.add(ProfileFavorite(user_id=current_user.id, world_id=wid))
+
+    await db.commit()
+    return FavoritesResponse(world_ids=world_ids)
+
+
+@router.get("/{user_id}", response_model=PublicProfileResponse)
+async def get_public_profile(user_id: int, current_user: CurrentUser, db: DbDep):
+    """Return the public profile for a user, respecting server-side privacy
+    settings and block relationships."""
+    user_res = await db.execute(select(User).where(User.id == user_id))
+    target_user = user_res.scalar_one_or_none()
+    if target_user is None or not target_user.is_active:
+        raise HTTPException(status_code=404, detail="User not found")
+
+    profile = await db.get(Profile, user_id)
+    avatar_asset = None
+    if profile and profile.avatar_asset_id:
+        avatar_asset = await db.get(Asset, profile.avatar_asset_id)
+
+    privacy = dict(DEFAULT_PRIVACY)
+    if profile and profile.privacy_json:
+        privacy.update(profile.privacy_json)
+
+    is_self = current_user.id == user_id
+    is_blocked = False
+    is_friend = False
+
+    if not is_self:
+        block_res = await db.execute(
+            select(Block.id).where(
+                or_(
+                    and_(Block.blocker_id == current_user.id, Block.blocked_id == user_id),
+                    and_(Block.blocker_id == user_id, Block.blocked_id == current_user.id),
+                )
+            )
+        )
+        is_blocked = block_res.scalar_one_or_none() is not None
+
+        if not is_blocked:
+            friend_res = await db.execute(
+                select(Friendship.id).where(
+                    or_(
+                        and_(Friendship.requester_id == current_user.id, Friendship.addressee_id == user_id),
+                        and_(Friendship.requester_id == user_id, Friendship.addressee_id == current_user.id),
+                    ),
+                    Friendship.status == FriendshipStatus.ACCEPTED,
+                )
+            )
+            is_friend = friend_res.scalar_one_or_none() is not None
+
+    profile_vis = privacy.get("profile_visibility", ProfileVisibility.PUBLIC.value)
+    if profile_vis is False:
+        profile_vis = ProfileVisibility.PRIVATE.value
+    elif profile_vis is True:
+        profile_vis = ProfileVisibility.PUBLIC.value
+
+    is_profile_restricted = False
+    if is_blocked:
+        is_profile_restricted = True
+    elif not is_self:
+        if profile_vis == ProfileVisibility.PRIVATE.value:
+            is_profile_restricted = True
+        elif profile_vis == ProfileVisibility.FRIENDS.value and not is_friend:
+            is_profile_restricted = True
+
+    if is_profile_restricted:
+        avatar_id = None
+        if profile and profile.avatar_asset_id:
+            if avatar_asset and avatar_asset.is_public:
+                avatar_id = profile.avatar_asset_id
+        return PublicProfileResponse(
+            user_id=target_user.id,
+            username=target_user.username,
+            avatar_asset_id=avatar_id,
+            bio=None,
+            favorites=[],
+            friends=[],
+            is_restricted=True,
+        )
+
+    avatar_id = profile.avatar_asset_id if profile else None
+    bio = profile.bio if profile else None
+
+    fav_vis = privacy.get("favorites_visibility", ProfileVisibility.PUBLIC.value)
+    if fav_vis is False:
+        fav_vis = ProfileVisibility.PRIVATE.value
+    elif fav_vis is True:
+        fav_vis = ProfileVisibility.PUBLIC.value
+
+    can_see_favorites = is_self or (fav_vis == ProfileVisibility.PUBLIC.value) or (fav_vis == ProfileVisibility.FRIENDS.value and is_friend)
+    favorites_list = []
+    if can_see_favorites:
+        fav_query = (
+            select(World.id, World.name)
+            .join(ProfileFavorite, ProfileFavorite.world_id == World.id)
+            .where(ProfileFavorite.user_id == user_id)
+            .order_by(ProfileFavorite.created_at.desc())
+        )
+        fav_res = await db.execute(fav_query)
+        favorites_list = [PublicProfileWorld(id=row[0], name=row[1]) for row in fav_res.all()]
+
+    fr_vis = privacy.get("friends_list_visibility", ProfileVisibility.PUBLIC.value)
+    if fr_vis is False:
+        fr_vis = ProfileVisibility.PRIVATE.value
+    elif fr_vis is True:
+        fr_vis = ProfileVisibility.PUBLIC.value
+
+    can_see_friends = is_self or (fr_vis == ProfileVisibility.PUBLIC.value) or (fr_vis == ProfileVisibility.FRIENDS.value and is_friend)
+    friends_list = []
+    if can_see_friends:
+        fr_res = await db.execute(
+            select(Friendship).where(
+                or_(Friendship.requester_id == user_id, Friendship.addressee_id == user_id),
+                Friendship.status == FriendshipStatus.ACCEPTED,
+            )
+        )
+        friendships = fr_res.scalars().all()
+        other_ids = [
+            fr.addressee_id if fr.requester_id == user_id else fr.requester_id
+            for fr in friendships
+        ]
+        if other_ids:
+            users_res = await db.execute(
+                select(User.id, User.username).where(User.id.in_(other_ids), User.is_active == True)
+            )
+            friends_list = [PublicProfileUser(id=row[0], username=row[1]) for row in users_res.all()]
+
+    return PublicProfileResponse(
+        user_id=target_user.id,
+        username=target_user.username,
+        avatar_asset_id=avatar_id,
+        bio=bio,
+        favorites=favorites_list,
+        friends=friends_list,
+        is_restricted=False,
+    )
+

backend/app/routers/social_friends.py

@@ -0,0 +1,362 @@
+"""Friends/follow/block router.
+
+docs/planning/social.md §4/§5 (US-1). Builds the request/accept/block
+business logic on top of the models in app/models/social.py (already
+merged): friend requests are directional (requester -> addressee) until
+accepted, at which point the relationship is treated as mutual; follow is
+one-way with no approval step; block is a hard deny that clears any
+existing friendship/follow between the two users and is queryable so a
+later layer (e.g. chat) can check it -- enforcing the block anywhere but
+here is out of scope for this router.
+
+Endpoints:
+- POST   /api/friends/requests                -- send a friend request
+- GET    /api/friends/requests                -- list incoming (pending) requests
+- POST   /api/friends/requests/{id}/accept    -- accept an incoming request
+- POST   /api/friends/requests/{id}/decline   -- decline an incoming request
+- DELETE /api/friends/{user_id}                -- unfriend
+- POST   /api/friends/{user_id}/follow         -- follow a user
+- DELETE /api/friends/{user_id}/follow         -- unfollow a user
+- POST   /api/friends/{user_id}/block          -- block a user
+- DELETE /api/friends/{user_id}/block          -- unblock a user
+- GET    /api/friends                          -- list friends
+- GET    /api/friends/following                -- list users followed
+- GET    /api/friends/blocked                  -- list blocked users
+"""
+
+from datetime import datetime
+from typing import Annotated
+
+from fastapi import APIRouter, HTTPException, status, Depends
+from pydantic import BaseModel
+from sqlalchemy import select, delete, or_, and_
+from sqlalchemy.exc import IntegrityError
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.database import get_db
+from app.dependencies import CurrentUser
+from app.models.social import Friendship, Follow, Block, FriendshipStatus
+from app.models.user import User
+
+router = APIRouter()
+
+DbDep = Annotated[AsyncSession, Depends(get_db)]
+
+# ──────────────────────────── Pydantic schemas ────────────────────────────────
+
+
+class FriendRequestCreate(BaseModel):
+    user_id: int
+
+
+class FriendRequestResponse(BaseModel):
+    id: int
+    requester_id: int
+    addressee_id: int
+    status: FriendshipStatus
+    created_at: datetime
+
+    model_config = {"from_attributes": True}
+
+
+class UserSummary(BaseModel):
+    id: int
+    username: str
+
+    model_config = {"from_attributes": True}
+
+
+class FriendRequestListResponse(BaseModel):
+    requests: list[FriendRequestResponse]
+
+
+class FriendListResponse(BaseModel):
+    friends: list[UserSummary]
+
+
+class FollowListResponse(BaseModel):
+    following: list[UserSummary]
+
+
+class BlockedListResponse(BaseModel):
+    blocked: list[UserSummary]
+
+
+class ActionResponse(BaseModel):
+    status: str
+
+
+# ──────────────────────────────── Helpers ──────────────────────────────────────
+
+
+def _friendship_pair(a: int, b: int):
+    """SQLAlchemy predicate matching a Friendship row between a and b,
+    regardless of which one is the requester/addressee."""
+    return or_(
+        and_(Friendship.requester_id == a, Friendship.addressee_id == b),
+        and_(Friendship.requester_id == b, Friendship.addressee_id == a),
+    )
+
+
+def _follow_pair(a: int, b: int):
+    """Predicate matching a Follow row in either direction between a and b."""
+    return or_(
+        and_(Follow.follower_id == a, Follow.followed_id == b),
+        and_(Follow.follower_id == b, Follow.followed_id == a),
+    )
+
+
+async def _is_blocked_either_direction(db: AsyncSession, a: int, b: int) -> bool:
+    result = await db.execute(
+        select(Block.id).where(
+            or_(
+                and_(Block.blocker_id == a, Block.blocked_id == b),
+                and_(Block.blocker_id == b, Block.blocked_id == a),
+            )
+        )
+    )
+    return result.scalar_one_or_none() is not None
+
+
+async def _get_user_or_404(db: AsyncSession, user_id: int) -> User:
+    result = await db.execute(select(User).where(User.id == user_id))
+    user = result.scalar_one_or_none()
+    if user is None:
+        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="User not found")
+    return user
+
+
+# ──────────────────────────────── Requests ─────────────────────────────────────
+
+
+@router.post("/requests", response_model=FriendRequestResponse, status_code=status.HTTP_201_CREATED)
+async def send_friend_request(body: FriendRequestCreate, current_user: CurrentUser, db: DbDep):
+    """Send a friend request to another user."""
+    target_id = body.user_id
+    if target_id == current_user.id:
+        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="Cannot send a friend request to yourself")
+
+    await _get_user_or_404(db, target_id)
+
+    if await _is_blocked_either_direction(db, current_user.id, target_id):
+        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Cannot send a friend request to this user")
+
+    existing = await db.execute(select(Friendship).where(_friendship_pair(current_user.id, target_id)))
+    if existing.scalar_one_or_none() is not None:
+        raise HTTPException(status_code=status.HTTP_409_CONFLICT, detail="Friend request or friendship already exists")
+
+    fr = Friendship(requester_id=current_user.id, addressee_id=target_id)
+    db.add(fr)
+    try:
+        await db.commit()
+    except IntegrityError:
+        await db.rollback()
+        raise HTTPException(status_code=status.HTTP_409_CONFLICT, detail="Friend request or friendship already exists")
+    await db.refresh(fr)
+    return fr
+
+
+@router.get("/requests", response_model=FriendRequestListResponse)
+async def list_incoming_requests(current_user: CurrentUser, db: DbDep):
+    """List pending friend requests sent *to* the authenticated user."""
+    result = await db.execute(
+        select(Friendship).where(
+            Friendship.addressee_id == current_user.id,
+            Friendship.status == FriendshipStatus.PENDING,
+        )
+    )
+    return FriendRequestListResponse(requests=list(result.scalars().all()))
+
+
+@router.post("/requests/{request_id}/accept", response_model=FriendRequestResponse)
+async def accept_friend_request(request_id: int, current_user: CurrentUser, db: DbDep):
+    """Accept an incoming friend request, making the friendship mutual."""
+    result = await db.execute(select(Friendship).where(Friendship.id == request_id))
+    fr = result.scalar_one_or_none()
+    # 404 (not a 403) both when the row doesn't exist and when it isn't
+    # addressed to the caller, so ids can't be enumerated to probe other
+    # accounts' pending requests.
+    if fr is None or fr.addressee_id != current_user.id or fr.status != FriendshipStatus.PENDING:
+        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Friend request not found")
+
+    fr.status = FriendshipStatus.ACCEPTED
+    await db.commit()
+    await db.refresh(fr)
+    return fr
+
+
+@router.post("/requests/{request_id}/decline", response_model=ActionResponse)
+async def decline_friend_request(request_id: int, current_user: CurrentUser, db: DbDep):
+    """Decline (and remove) an incoming friend request."""
+    result = await db.execute(select(Friendship).where(Friendship.id == request_id))
+    fr = result.scalar_one_or_none()
+    if fr is None or fr.addressee_id != current_user.id or fr.status != FriendshipStatus.PENDING:
+        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Friend request not found")
+
+    await db.delete(fr)
+    await db.commit()
+    return ActionResponse(status="declined")
+
+
+# ──────────────────────────────── Friends ──────────────────────────────────────
+
+
+@router.get("", response_model=FriendListResponse)
+async def list_friends(current_user: CurrentUser, db: DbDep):
+    """List the authenticated user's accepted friends."""
+    result = await db.execute(
+        select(Friendship).where(
+            or_(Friendship.requester_id == current_user.id, Friendship.addressee_id == current_user.id),
+            Friendship.status == FriendshipStatus.ACCEPTED,
+        )
+    )
+    friendships = result.scalars().all()
+    other_ids = [
+        fr.addressee_id if fr.requester_id == current_user.id else fr.requester_id
+        for fr in friendships
+    ]
+    if not other_ids:
+        return FriendListResponse(friends=[])
+
+    users_result = await db.execute(select(User).where(User.id.in_(other_ids)))
+    return FriendListResponse(friends=list(users_result.scalars().all()))
+
+
+@router.delete("/{user_id}", response_model=ActionResponse)
+async def unfriend(user_id: int, current_user: CurrentUser, db: DbDep):
+    """Remove an existing (accepted) friendship."""
+    if user_id == current_user.id:
+        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="Cannot unfriend yourself")
+
+    result = await db.execute(
+        select(Friendship).where(
+            _friendship_pair(current_user.id, user_id),
+            Friendship.status == FriendshipStatus.ACCEPTED,
+        )
+    )
+    fr = result.scalar_one_or_none()
+    if fr is None:
+        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Not friends with this user")
+
+    await db.delete(fr)
+    await db.commit()
+    return ActionResponse(status="unfriended")
+
+
+# ──────────────────────────────── Follow ───────────────────────────────────────
+
+
+@router.post("/{user_id}/follow", response_model=ActionResponse, status_code=status.HTTP_201_CREATED)
+async def follow_user(user_id: int, current_user: CurrentUser, db: DbDep):
+    """Follow another user (one-way, no approval)."""
+    if user_id == current_user.id:
+        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="Cannot follow yourself")
+
+    await _get_user_or_404(db, user_id)
+
+    if await _is_blocked_either_direction(db, current_user.id, user_id):
+        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Cannot follow this user")
+
+    existing = await db.execute(
+        select(Follow).where(Follow.follower_id == current_user.id, Follow.followed_id == user_id)
+    )
+    if existing.scalar_one_or_none() is not None:
+        raise HTTPException(status_code=status.HTTP_409_CONFLICT, detail="Already following this user")
+
+    db.add(Follow(follower_id=current_user.id, followed_id=user_id))
+    try:
+        await db.commit()
+    except IntegrityError:
+        await db.rollback()
+        raise HTTPException(status_code=status.HTTP_409_CONFLICT, detail="Already following this user")
+    return ActionResponse(status="followed")
+
+
+@router.delete("/{user_id}/follow", response_model=ActionResponse)
+async def unfollow_user(user_id: int, current_user: CurrentUser, db: DbDep):
+    """Unfollow a user."""
+    if user_id == current_user.id:
+        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="Cannot unfollow yourself")
+
+    result = await db.execute(
+        select(Follow).where(Follow.follower_id == current_user.id, Follow.followed_id == user_id)
+    )
+    follow = result.scalar_one_or_none()
+    if follow is None:
+        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Not following this user")
+
+    await db.delete(follow)
+    await db.commit()
+    return ActionResponse(status="unfollowed")
+
+
+@router.get("/following", response_model=FollowListResponse)
+async def list_following(current_user: CurrentUser, db: DbDep):
+    """List users the authenticated user follows."""
+    result = await db.execute(select(Follow).where(Follow.follower_id == current_user.id))
+    followed_ids = [f.followed_id for f in result.scalars().all()]
+    if not followed_ids:
+        return FollowListResponse(following=[])
+
+    users_result = await db.execute(select(User).where(User.id.in_(followed_ids)))
+    return FollowListResponse(following=list(users_result.scalars().all()))
+
+
+# ──────────────────────────────── Block ────────────────────────────────────────
+
+
+@router.post("/{user_id}/block", response_model=ActionResponse, status_code=status.HTTP_201_CREATED)
+async def block_user(user_id: int, current_user: CurrentUser, db: DbDep):
+    """Block a user: hard deny that also clears any existing friendship/follow
+    between the two users in either direction."""
+    if user_id == current_user.id:
+        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="Cannot block yourself")
+
+    await _get_user_or_404(db, user_id)
+
+    existing = await db.execute(
+        select(Block).where(Block.blocker_id == current_user.id, Block.blocked_id == user_id)
+    )
+    if existing.scalar_one_or_none() is not None:
+        raise HTTPException(status_code=status.HTTP_409_CONFLICT, detail="User already blocked")
+
+    db.add(Block(blocker_id=current_user.id, blocked_id=user_id))
+    await db.execute(delete(Friendship).where(_friendship_pair(current_user.id, user_id)))
+    await db.execute(delete(Follow).where(_follow_pair(current_user.id, user_id)))
+
+    try:
+        await db.commit()
+    except IntegrityError:
+        await db.rollback()
+        raise HTTPException(status_code=status.HTTP_409_CONFLICT, detail="User already blocked")
+    return ActionResponse(status="blocked")
+
+
+@router.delete("/{user_id}/block", response_model=ActionResponse)
+async def unblock_user(user_id: int, current_user: CurrentUser, db: DbDep):
+    """Remove a block."""
+    if user_id == current_user.id:
+        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="Cannot unblock yourself")
+
+    result = await db.execute(
+        select(Block).where(Block.blocker_id == current_user.id, Block.blocked_id == user_id)
+    )
+    block = result.scalar_one_or_none()
+    if block is None:
+        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="User is not blocked")
+
+    await db.delete(block)
+    await db.commit()
+    return ActionResponse(status="unblocked")
+
+
+@router.get("/blocked", response_model=BlockedListResponse)
+async def list_blocked(current_user: CurrentUser, db: DbDep):
+    """List users the authenticated user has blocked."""
+    result = await db.execute(select(Block).where(Block.blocker_id == current_user.id))
+    blocked_ids = [b.blocked_id for b in result.scalars().all()]
+    if not blocked_ids:
+        return BlockedListResponse(blocked=[])
+
+    users_result = await db.execute(select(User).where(User.id.in_(blocked_ids)))
+    return BlockedListResponse(blocked=list(users_result.scalars().all()))

backend/app/routers/wallet.py

@@ -0,0 +1,78 @@
+"""Wallet & transactions API endpoints.
+
+docs/planning/economy.md US-1 (task 909e3e9a59af).
+"""
+
+from datetime import datetime
+from typing import Annotated, Any
+
+from fastapi import APIRouter, Depends, HTTPException, Query, status
+from pydantic import BaseModel, Field
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.database import get_db
+from app.dependencies import CurrentUser
+from app.models.wallet import TransactionType
+from app.services.wallet import wallet_service
+
+router = APIRouter()
+
+DbDep = Annotated[AsyncSession, Depends(get_db)]
+
+
+class WalletResponse(BaseModel):
+    id: int
+    user_id: int
+    balance: int
+    created_at: datetime
+    updated_at: datetime
+
+    model_config = {"from_attributes": True}
+
+
+class TransactionResponse(BaseModel):
+    id: int
+    wallet_id: int
+    type: TransactionType
+    amount: int
+    balance_after: int
+    reference_type: str | None = None
+    reference_id: str | None = None
+    idempotency_key: str | None = None
+    metadata_json: dict[str, Any] | None = None
+    created_at: datetime
+
+    model_config = {"from_attributes": True}
+
+
+class TransactionListResponse(BaseModel):
+    transactions: list[TransactionResponse]
+    total: int
+    limit: int
+    offset: int
+
+
+@router.get("", response_model=WalletResponse)
+@router.get("/", response_model=WalletResponse)
+async def get_wallet(current_user: CurrentUser, db: DbDep):
+    """Retrieve the current user's wallet balance and metadata."""
+    wallet = await wallet_service.get_or_create_wallet(db, current_user.id)
+    return wallet
+
+
+@router.get("/transactions", response_model=TransactionListResponse)
+async def get_wallet_transactions(
+    current_user: CurrentUser,
+    db: DbDep,
+    limit: int = Query(50, ge=1, le=100),
+    offset: int = Query(0, ge=0),
+):
+    """List the current user's ledger transactions, ordered newest-first."""
+    wallet = await wallet_service.get_or_create_wallet(db, current_user.id)
+    txs, total = await wallet_service.get_transactions(db, wallet.id, limit=limit, offset=offset)
+    return TransactionListResponse(
+        transactions=txs,
+        total=total,
+        limit=limit,
+        offset=offset,
+    )

backend/app/services/chat_pubsub.py

@@ -0,0 +1,48 @@
+"""Pub/sub messaging bus for chat events over Redis.
+
+Provides asynchronous publish hooks for world/room chat and DMs, allowing the
+WebSocket real-time gateway (and multi-instance replicas) to receive and fan out
+chat messages in real time.
+"""
+
+from __future__ import annotations
+
+import json
+import logging
+from typing import Any
+
+import redis.asyncio as aioredis
+
+from app.config import settings
+
+logger = logging.getLogger(__name__)
+
+
+async def publish_world_chat_event(
+    world_id: int, payload: dict[str, Any], room_id: int | None = None
+) -> None:
+    """Publish a world chat message event to Redis pub/sub for real-time delivery."""
+    try:
+        client = aioredis.from_url(settings.REDIS_URL, encoding="utf-8", decode_responses=True)
+        async with client:
+            channel = f"world:{world_id}:chat"
+            data = json.dumps(payload, default=str)
+            await client.publish(channel, data)
+            if room_id is not None:
+                await client.publish(f"room:{room_id}:chat", data)
+    except Exception as exc:
+        logger.debug("Failed to publish world chat event to Redis: %s", exc)
+
+
+async def publish_dm_chat_event(
+    conversation_id: int, payload: dict[str, Any]
+) -> None:
+    """Publish a DM chat message event to Redis pub/sub for real-time delivery."""
+    try:
+        client = aioredis.from_url(settings.REDIS_URL, encoding="utf-8", decode_responses=True)
+        async with client:
+            channel = f"dm:{conversation_id}:chat"
+            data = json.dumps(payload, default=str)
+            await client.publish(channel, data)
+    except Exception as exc:
+        logger.debug("Failed to publish DM chat event to Redis: %s", exc)

backend/app/services/chunk_codec.py

@@ -127,10 +127,15 @@ class WorldObject:
 
 @dataclass
 class ChunkBounds:
-    """Wire representation is min-corner + size (matching the Godot AABB
+    """Stored here as min-corner + size (matching the Godot client's AABB
-    the reference encoder builds from), not min/max as world.md §3.1's
+    type) for convenience, but the §3.6 BINARY wire format is min + max
-    logical-model prose describes -- both are fully recoverable from each
+    (world.md §3.1, and the client's actual ChunkDataDecoder) -- fixed
-    other; this is just the on-the-wire convention."""
+    2026-09-14 after a real client/server interop test caught this class's
+    original binary codec writing min+size on the wire, which the client
+    decoder (unaware of the "size" convention) read as a second min/max
+    pair, corrupting every chunk's bounds. The two representations are
+    fully recoverable from each other; `max` below is computed for exactly
+    this reason."""
 
     min: tuple[float, float, float] = (0.0, 0.0, 0.0)
     size: tuple[float, float, float] = (0.0, 0.0, 0.0)
@@ -237,9 +242,9 @@ def _encode_metadata(payload: ChunkPayload) -> bytes:
     out += _w_f32(payload.bounds.min[0])
     out += _w_f32(payload.bounds.min[1])
     out += _w_f32(payload.bounds.min[2])
-    out += _w_f32(payload.bounds.size[0])
+    out += _w_f32(payload.bounds.max[0])
-    out += _w_f32(payload.bounds.size[1])
+    out += _w_f32(payload.bounds.max[1])
-    out += _w_f32(payload.bounds.size[2])
+    out += _w_f32(payload.bounds.max[2])
     return bytes(out)
 
 
@@ -250,7 +255,8 @@ def _decode_metadata(data: bytes, result: ChunkPayload) -> None:
     coord = (_read_i32(data, off), _read_i32(data, off + 4), _read_i32(data, off + 8))
     off += 12
     min_pos = (_read_f32(data, off), _read_f32(data, off + 4), _read_f32(data, off + 8))
-    size = (_read_f32(data, off + 12), _read_f32(data, off + 16), _read_f32(data, off + 20))
+    max_pos = (_read_f32(data, off + 12), _read_f32(data, off + 16), _read_f32(data, off + 20))
+    size = tuple(a - b for a, b in zip(max_pos, min_pos))
     result.coord = coord
     result.bounds = ChunkBounds(min=min_pos, size=size)
 

backend/app/services/payment.py

@@ -0,0 +1,89 @@
+"""PaymentProvider interface and NoopPaymentProvider implementation.
+
+docs/planning/economy.md US-2 (task 575fd14b5360).
+"""
+
+from __future__ import annotations
+
+from dataclasses import dataclass, field
+from datetime import datetime, timezone
+from typing import Protocol
+import uuid
+
+ALLOWED_CREDIT_PACKS: set[int] = {100, 500, 1000, 5000}
+
+
+@dataclass
+class PurchaseSession:
+    session_id: str
+    user_id: int
+    credits: int
+    provider_ref: str
+    status: str = "created"  # created, confirmed, failed
+    created_at: datetime = field(default_factory=lambda: datetime.now(timezone.utc))
+
+
+@dataclass
+class Confirmation:
+    confirmed: bool
+    provider_ref: str
+    credits: int
+    user_id: int
+
+
+class PaymentProvider(Protocol):
+    """Pluggable payment provider protocol (e.g. Stripe, PayPal, Noop)."""
+
+    async def create_purchase(
+        self, user_id: int, credits: int, idempotency_key: str | None = None
+    ) -> PurchaseSession:
+        ...
+
+    async def confirm(self, session_id: str) -> Confirmation:
+        ...
+
+
+class NoopPaymentProvider:
+    """Deterministic, no-op payment provider for local development and testing.
+
+    Returns confirmed=True with a simulated provider reference. Clearly non-production.
+    """
+
+    def __init__(self) -> None:
+        self._sessions: dict[str, PurchaseSession] = {}
+
+    async def create_purchase(
+        self, user_id: int, credits: int, idempotency_key: str | None = None
+    ) -> PurchaseSession:
+        session_id = f"sess_{uuid.uuid4().hex[:16]}"
+        provider_ref = f"noop_tx_{uuid.uuid4().hex[:12]}"
+        sess = PurchaseSession(
+            session_id=session_id,
+            user_id=user_id,
+            credits=credits,
+            provider_ref=provider_ref,
+            status="created",
+        )
+        self._sessions[session_id] = sess
+        return sess
+
+    async def confirm(self, session_id: str) -> Confirmation:
+        sess = self._sessions.get(session_id)
+        if sess is None:
+            return Confirmation(
+                confirmed=False,
+                provider_ref="",
+                credits=0,
+                user_id=0,
+            )
+
+        sess.status = "confirmed"
+        return Confirmation(
+            confirmed=True,
+            provider_ref=sess.provider_ref,
+            credits=sess.credits,
+            user_id=sess.user_id,
+        )
+
+
+payment_provider: PaymentProvider = NoopPaymentProvider()

backend/app/services/presence.py

@@ -0,0 +1,150 @@
+"""Redis-backed presence store.
+
+Presence is determined by a heartbeat TTL key in Redis:
+- heartbeat(user_id) sets a TTL key per user (default 60 s).
+- is_online(user_id) / is_online_batch(user_ids) check whether the key(s)
+  exist.
+
+status_message and last_seen_at are persisted in the ``users`` table by the
+router (app/routers/presence.py); this store only owns the Redis side.
+
+The Redis client is created lazily, on first actual use, rather than
+requiring an explicit ``connect()`` call during app startup. This matters
+because FastAPI's lifespan handler does not run under the plain
+``TestClient(app)`` instantiation this codebase's tests use (no
+``with`` block), so anything that only connected during lifespan startup
+would never connect in tests. Lazy connection means the store works
+identically whether the app was started for real or is being driven by
+pytest.
+
+The client is also cached per-*event loop* rather than globally: the same
+plain ``TestClient(app)`` pattern can dispatch different requests onto
+different event loops (see the NullPool comment on ``_override_db`` in
+tests/conftest.py for the analogous asyncpg problem), and an
+``aioredis.Redis`` connection, like an asyncpg connection, breaks with
+"Event loop is closed" if reused across loops. In the real running server
+there is exactly one event loop for the process lifetime, so this
+degrades to a single cached, pooled connection there.
+"""
+
+from __future__ import annotations
+
+import asyncio
+import logging
+
+import redis.asyncio as aioredis
+
+from app.config import settings
+
+logger = logging.getLogger(__name__)
+
+# Key prefix for heartbeat entries.
+_PRESENCE_KEY_PREFIX = "presence:heartbeat:"
+
+# Default heartbeat TTL in seconds (1 minute).
+# Clients should heartbeat at least once per interval.
+_DEFAULT_HEARTBEAT_TTL = 60
+
+
+class PresenceStore:
+    """Redis-backed presence store with async, lazily-connected operations."""
+
+    def __init__(self, redis_url: str | None = None, heartbeat_ttl: int = _DEFAULT_HEARTBEAT_TTL):
+        # redis_url is resolved from settings at first use (not at
+        # construction time) so tests that override settings.REDIS_URL
+        # before the first call still take effect -- this module is
+        # imported (and the module-level singleton below constructed)
+        # well before any such override runs.
+        self._redis_url = redis_url
+        self._heartbeat_ttl = heartbeat_ttl
+        # Keyed by id(running loop) -- see the module docstring.
+        self._clients: dict[int, aioredis.Redis] = {}
+        self._connect_lock = asyncio.Lock()
+
+    # ------------------------------------------------------------------
+    # Lifecycle
+    # ------------------------------------------------------------------
+
+    async def _ensure_client(self) -> aioredis.Redis:
+        """Return a connected client for the current event loop, connecting
+        on first use per loop."""
+        loop_key = id(asyncio.get_running_loop())
+        client = self._clients.get(loop_key)
+        if client is None:
+            async with self._connect_lock:
+                client = self._clients.get(loop_key)
+                if client is None:
+                    url = self._redis_url or settings.REDIS_URL
+                    client = aioredis.from_url(
+                        url,
+                        encoding="utf-8",
+                        decode_responses=True,
+                    )
+                    try:
+                        await client.ping()
+                    except Exception:
+                        logger.warning("Redis ping failed for %s", url)
+                        raise
+                    self._clients[loop_key] = client
+        return client
+
+    async def close(self) -> None:
+        """Close the Redis connection for the current event loop, if one was
+        opened."""
+        loop_key = id(asyncio.get_running_loop())
+        client = self._clients.pop(loop_key, None)
+        if client is not None:
+            await client.aclose()
+
+    # ------------------------------------------------------------------
+    # Heartbeat
+    # ------------------------------------------------------------------
+
+    async def heartbeat(self, user_id: int) -> None:
+        """Record a heartbeat for *user_id*.
+
+        Sets a TTL key so that the user is considered online as long as
+        heartbeats arrive at least once per heartbeat_ttl seconds.
+        """
+        client = await self._ensure_client()
+        await client.set(self._heartbeat_key(user_id), "1", ex=self._heartbeat_ttl)
+
+    async def clear_heartbeat(self, user_id: int) -> None:
+        """Clear heartbeat for *user_id* to mark them offline immediately."""
+        client = await self._ensure_client()
+        await client.delete(self._heartbeat_key(user_id))
+
+    # ------------------------------------------------------------------
+    # Online checks
+    # ------------------------------------------------------------------
+
+    async def is_online(self, user_id: int) -> bool:
+        """Return True if the user has a valid heartbeat key."""
+        client = await self._ensure_client()
+        exists = await client.exists(self._heartbeat_key(user_id))
+        return bool(exists)
+
+    async def is_online_batch(self, user_ids: list[int]) -> set[int]:
+        """Return the subset of user_ids that currently have a valid
+        heartbeat key. Uses MGET (one round trip) rather than one EXISTS
+        per user.
+        """
+        if not user_ids:
+            return set()
+        client = await self._ensure_client()
+        keys = [self._heartbeat_key(uid) for uid in user_ids]
+        values = await client.mget(keys)
+        return {uid for uid, v in zip(user_ids, values) if v is not None}
+
+    # ------------------------------------------------------------------
+    # Helpers
+    # ------------------------------------------------------------------
+
+    @staticmethod
+    def _heartbeat_key(user_id: int) -> str:
+        return f"{_PRESENCE_KEY_PREFIX}{user_id}"
+
+
+# Singleton instance shared by the router, so all requests share the same
+# connection pool.
+presence_store = PresenceStore()

backend/app/services/purchase.py

@@ -0,0 +1,251 @@
+"""Marketplace purchase service: atomic escrow, fee split, item granting, refunds.
+
+docs/planning/economy.md US-4 (task bc90d3f481b4).
+"""
+
+from __future__ import annotations
+
+from datetime import datetime, timedelta, timezone
+import math
+from typing import Any
+
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.models.marketplace import (
+    CatalogItem,
+    CreatorBalance,
+    ListingStatus,
+    MarketplaceListing,
+    Purchase,
+    PurchaseStatus,
+)
+from app.models.wallet import TransactionType
+from app.services.wallet import InsufficientFundsError, WalletService
+
+
+MARKETPLACE_FEE_RATE = 0.30  # 30% platform fee
+DEFAULT_ESCROW_HOLD_HOURS = 72
+
+
+class ListingNotFoundError(Exception):
+    """Raised when the specified listing does not exist."""
+    pass
+
+
+class ListingNotAvailableError(Exception):
+    """Raised when the listing is not in active status."""
+    pass
+
+
+class SelfPurchaseError(Exception):
+    """Raised when a seller attempts to buy their own listing."""
+    pass
+
+
+class PurchaseNotFoundError(Exception):
+    """Raised when the specified purchase does not exist."""
+    pass
+
+
+class InvalidEscrowStateError(Exception):
+    """Raised when an operation cannot be performed on the current escrow state."""
+    pass
+
+
+class PurchaseService:
+    @staticmethod
+    def compute_fee_split(price: int, fee_rate: float = MARKETPLACE_FEE_RATE) -> tuple[int, int]:
+        """Compute platform fee and seller net amount.
+
+        Returns (platform_fee, seller_net).
+        """
+        platform_fee = math.floor(price * fee_rate)
+        seller_net = price - platform_fee
+        return platform_fee, seller_net
+
+    @classmethod
+    async def get_or_create_creator_balance(
+        cls, db: AsyncSession, user_id: int, for_update: bool = False
+    ) -> CreatorBalance:
+        """Fetch or lazily create a creator balance row for user_id."""
+        stmt = select(CreatorBalance).where(CreatorBalance.user_id == user_id)
+        if for_update:
+            stmt = stmt.with_for_update()
+        result = await db.execute(stmt)
+        cb = result.scalar_one_or_none()
+        if cb is not None:
+            return cb
+
+        new_cb = CreatorBalance(
+            user_id=user_id,
+            available=0,
+            pending=0,
+            lifetime_earned=0,
+        )
+        db.add(new_cb)
+        await db.flush()
+        return new_cb
+
+    @classmethod
+    async def purchase_listing(
+        cls,
+        db: AsyncSession,
+        buyer_id: int,
+        listing_id: int,
+        idempotency_key: str | None = None,
+        escrow_hours: int = DEFAULT_ESCROW_HOLD_HOURS,
+    ) -> tuple[Purchase, CatalogItem]:
+        """Perform atomic purchase of a marketplace listing.
+
+        Debits buyer, holds escrow, grants item to buyer, records purchase,
+        and updates creator pending balance.
+        """
+        # 1. Lock and validate listing
+        stmt_listing = (
+            select(MarketplaceListing)
+            .where(MarketplaceListing.id == listing_id)
+            .with_for_update()
+        )
+        res_listing = await db.execute(stmt_listing)
+        listing = res_listing.scalar_one_or_none()
+        if listing is None:
+            raise ListingNotFoundError(f"Listing {listing_id} not found")
+
+        if listing.status != ListingStatus.active:
+            raise ListingNotAvailableError(f"Listing {listing_id} is not active ({listing.status.value})")
+
+        if listing.seller_id == buyer_id:
+            raise SelfPurchaseError("Cannot purchase your own listing")
+
+        # 2. Fetch catalog item
+        catalog_item = await db.get(CatalogItem, listing.catalog_item_id)
+        if catalog_item is None:
+            raise ListingNotFoundError("Catalog item referenced by listing does not exist")
+
+        # 3. Calculate fee split
+        price = listing.price
+        platform_fee, seller_net = cls.compute_fee_split(price)
+
+        # 4. Debit buyer wallet atomically (commit=False)
+        tx_idemp = f"mkt-purchase-{idempotency_key}" if idempotency_key else None
+        await WalletService.debit(
+            db=db,
+            user_id=buyer_id,
+            amount=price,
+            tx_type=TransactionType.marketplace_purchase,
+            reference_type="marketplace_listing",
+            reference_id=str(listing.id),
+            idempotency_key=tx_idemp,
+            commit=False,
+        )
+
+        # 5. Grant catalog item to buyer
+        granted_item = CatalogItem(
+            owner_id=buyer_id,
+            asset_id=catalog_item.asset_id,
+            item_type=catalog_item.item_type,
+            name=catalog_item.name,
+            description=catalog_item.description,
+            metadata_json=catalog_item.metadata_json,
+        )
+        db.add(granted_item)
+
+        # 6. Mark listing as sold
+        now = datetime.now(timezone.utc)
+        listing.status = ListingStatus.sold
+        listing.updated_at = now
+
+        # 7. Create purchase record
+        hold_until = now + timedelta(hours=escrow_hours)
+        purchase = Purchase(
+            listing_id=listing.id,
+            buyer_id=buyer_id,
+            seller_id=listing.seller_id,
+            price=price,
+            platform_fee=platform_fee,
+            seller_net=seller_net,
+            status=PurchaseStatus.pending_escrow,
+            escrow_hold_until=hold_until,
+        )
+        db.add(purchase)
+
+        # 8. Update seller's CreatorBalance (pending escrow)
+        creator_balance = await cls.get_or_create_creator_balance(
+            db, listing.seller_id, for_update=True
+        )
+        creator_balance.pending += seller_net
+        creator_balance.updated_at = now
+
+        # Commit everything atomically
+        await db.commit()
+        await db.refresh(purchase)
+        await db.refresh(granted_item)
+
+        return purchase, granted_item
+
+    @classmethod
+    async def release_escrow(cls, db: AsyncSession, purchase_id: int) -> Purchase:
+        """Release funds from escrow to seller's available creator balance."""
+        stmt = select(Purchase).where(Purchase.id == purchase_id).with_for_update()
+        res = await db.execute(stmt)
+        purchase = res.scalar_one_or_none()
+        if purchase is None:
+            raise PurchaseNotFoundError(f"Purchase {purchase_id} not found")
+
+        if purchase.status != PurchaseStatus.pending_escrow:
+            raise InvalidEscrowStateError(
+                f"Cannot release escrow in status {purchase.status.value}"
+            )
+
+        cb = await cls.get_or_create_creator_balance(db, purchase.seller_id, for_update=True)
+        cb.pending = max(0, cb.pending - purchase.seller_net)
+        cb.available += purchase.seller_net
+        cb.lifetime_earned += purchase.seller_net
+        cb.updated_at = datetime.now(timezone.utc)
+
+        purchase.status = PurchaseStatus.completed
+        await db.commit()
+        await db.refresh(purchase)
+        return purchase
+
+    @classmethod
+    async def refund_purchase(
+        cls, db: AsyncSession, purchase_id: int, reason: str | None = None
+    ) -> Purchase:
+        """Refund a purchase during the escrow hold window."""
+        stmt = select(Purchase).where(Purchase.id == purchase_id).with_for_update()
+        res = await db.execute(stmt)
+        purchase = res.scalar_one_or_none()
+        if purchase is None:
+            raise PurchaseNotFoundError(f"Purchase {purchase_id} not found")
+
+        if purchase.status != PurchaseStatus.pending_escrow:
+            raise InvalidEscrowStateError(
+                f"Cannot refund purchase in status {purchase.status.value}"
+            )
+
+        # Reverse seller's pending creator balance
+        cb = await cls.get_or_create_creator_balance(db, purchase.seller_id, for_update=True)
+        cb.pending = max(0, cb.pending - purchase.seller_net)
+        cb.updated_at = datetime.now(timezone.utc)
+
+        # Credit buyer wallet
+        await WalletService.credit(
+            db=db,
+            user_id=purchase.buyer_id,
+            amount=purchase.price,
+            tx_type=TransactionType.refund,
+            reference_type="purchase_refund",
+            reference_id=str(purchase.id),
+            metadata={"reason": reason} if reason else None,
+            commit=False,
+        )
+
+        purchase.status = PurchaseStatus.refunded
+        await db.commit()
+        await db.refresh(purchase)
+        return purchase
+
+
+purchase_service = PurchaseService()

backend/app/services/text_filter.py

@@ -0,0 +1,304 @@
+"""Pluggable server-side text filtering, `docs/planning/social.md` §4/§5 (US-4).
+
+social.md §4 calls for a "Pluggable `TextFilter` interface with a
+deterministic default (profanity list + normalization) so it runs without
+external services; third-party hook later". This module is that interface
+plus the default implementation:
+
+- `TextFilter` is a `Protocol` -- the extension point. A future third-party
+  moderation provider (a paid API, an ML classifier, etc.) just needs to
+  implement `check(text) -> FilterResult`; nothing else in this module
+  needs to change, and callers depend on the protocol, not a concrete
+  class.
+- `ListBasedTextFilter` is the deterministic default: a configurable
+  term list (JSON file, see `text_filter_terms.json` next to this module)
+  matched against a normalized form of the input text so that trivial
+  evasion (case changes, leetspeak substitutions, and punctuation/spacing
+  inserted between letters) doesn't slip through.
+
+Nothing here talks to a database, an HTTP client, or the FastAPI app -- it
+is a pure, side-effect-free (aside from reading the term list file once, at
+construction) service so it can be unit tested in isolation. It is NOT
+wired into any router/endpoint by this task; that's for the chat feature
+tasks that depend on it (social.md §6) to do.
+
+Normalization approach
+-----------------------
+Matching naively against raw text misses "sh1t", "@ss", or "s.h.i.t". To
+catch these without a real tokenizer, every character of the input is
+independently normalized to at most one lowercase ASCII alphanumeric
+character (case-folded, then run through a small leetspeak substitution
+table); characters that don't reduce to `[a-z0-9]` (punctuation, spacing,
+symbols, non-ASCII) are dropped entirely rather than kept as separators.
+This collapses "s.h.i.t", "s h i t", and "SHIT" to the same normalized
+string ("shit") that a plain lowercase term list entry matches, while a
+side table (`index_map`) remembers which original character produced each
+surviving normalized character -- so a match found in the normalized
+string can still be translated back into a span of the *original* text for
+redaction.
+
+This is a deliberate precision/recall tradeoff common to list-based
+filters: stripping separators and folding leetspeak increases recall
+against evasion at the cost of occasionally matching a term inside an
+unrelated longer word (e.g. a 3-letter term inside a longer benign word).
+That tradeoff is exactly why this is pluggable -- a deployment that needs
+tighter precision can swap in a smarter `TextFilter` implementation behind
+the same protocol.
+"""
+
+from __future__ import annotations
+
+import json
+import re
+from dataclasses import dataclass
+from enum import Enum
+from pathlib import Path
+from typing import Iterable, Protocol, runtime_checkable
+
+# ---------------------------------------------------------------------------
+# Public result / protocol
+# ---------------------------------------------------------------------------
+
+
+class FilterAction(str, Enum):
+    """What the caller should do with a checked message."""
+
+    ALLOW = "allow"
+    REDACT = "redact"
+    REJECT = "reject"
+
+
+@dataclass(frozen=True)
+class FilterResult:
+    """Outcome of running a piece of text through a `TextFilter`.
+
+    - `action`: ALLOW (no matches), REDACT (matches replaced in
+      `filtered_text`), or REJECT (matches found; the message should be
+      blocked -- callers should not persist/deliver it even though
+      `filtered_text` is populated for logging/audit purposes).
+    - `filtered_text`: the text to actually store/deliver. Equal to the
+      input for ALLOW and REJECT; has matched spans replaced for REDACT.
+    - `matched_terms`: the distinct matched terms (original, un-normalized
+      list entries), in first-occurrence order. Empty for ALLOW.
+    """
+
+    action: FilterAction
+    filtered_text: str
+    matched_terms: tuple[str, ...] = ()
+
+
+@runtime_checkable
+class TextFilter(Protocol):
+    """Extension point for text filtering/moderation providers.
+
+    Any implementation -- the deterministic default below, or a future
+    third-party service call -- just needs this one method.
+    """
+
+    def check(self, text: str) -> FilterResult:
+        """Check `text` and return the action to take plus filtered text."""
+        ...
+
+
+class FilterMode(str, Enum):
+    """Configures what `ListBasedTextFilter` does when it finds a match."""
+
+    REDACT = "redact"
+    REJECT = "reject"
+
+
+# ---------------------------------------------------------------------------
+# Normalization
+# ---------------------------------------------------------------------------
+
+# Common leetspeak / lookalike substitutions, applied after case-folding.
+# Keys are already-lowercased single characters.
+_LEET_MAP: dict[str, str] = {
+    "0": "o",
+    "1": "i",
+    "!": "i",
+    "3": "e",
+    "4": "a",
+    "@": "a",
+    "5": "s",
+    "$": "s",
+    "7": "t",
+    "+": "t",
+    "8": "b",
+    "|": "l",
+}
+
+_ALNUM_RE = re.compile(r"[a-z0-9]")
+
+
+def _normalize(text: str) -> tuple[str, list[int]]:
+    """Fold `text` to a lowercase-alnum-only string plus an index map.
+
+    Returns `(normalized, index_map)` where `index_map[i]` is the index
+    into the *original* `text` that produced `normalized[i]`. Characters
+    that don't reduce to a single `[a-z0-9]` character (punctuation,
+    whitespace, symbols, most non-ASCII) are dropped from both outputs.
+    """
+    normalized_chars: list[str] = []
+    index_map: list[int] = []
+    for i, ch in enumerate(text):
+        folded = ch.casefold()
+        # case-fold can expand to multiple characters for some unicode
+        # (e.g. German "ß" -> "ss"); such characters are not part of the
+        # leetspeak table and are not plain ascii alnum, so just skip them
+        # like any other non-matching character rather than guessing.
+        if len(folded) != 1:
+            continue
+        folded = _LEET_MAP.get(folded, folded)
+        if _ALNUM_RE.fullmatch(folded):
+            normalized_chars.append(folded)
+            index_map.append(i)
+    return "".join(normalized_chars), index_map
+
+
+def _normalize_term(term: str) -> str:
+    normalized, _ = _normalize(term)
+    return normalized
+
+
+# ---------------------------------------------------------------------------
+# Default term list loading
+# ---------------------------------------------------------------------------
+
+DEFAULT_TERMS_PATH = Path(__file__).with_name("text_filter_terms.json")
+
+
+def load_terms(path: Path | str | None = None) -> list[str]:
+    """Load a term list from a JSON file shaped `{"terms": [...]}`.
+
+    Any other top-level keys (e.g. `_readme`) are ignored. Defaults to the
+    bundled `text_filter_terms.json` next to this module.
+    """
+    resolved = Path(path) if path is not None else DEFAULT_TERMS_PATH
+    with resolved.open("r", encoding="utf-8") as f:
+        data = json.load(f)
+    terms = data.get("terms", [])
+    if not isinstance(terms, list):
+        raise ValueError(f"{resolved}: 'terms' must be a list")
+    return [str(t) for t in terms]
+
+
+# ---------------------------------------------------------------------------
+# Span merging / redaction helpers
+# ---------------------------------------------------------------------------
+
+
+def _merge_spans(spans: list[tuple[int, int, str]]) -> list[tuple[int, int]]:
+    """Merge overlapping/adjacent (start, end) spans, sorted by start."""
+    if not spans:
+        return []
+    ordered = sorted((s, e) for s, e, _ in spans)
+    merged: list[tuple[int, int]] = [ordered[0]]
+    for start, end in ordered[1:]:
+        last_start, last_end = merged[-1]
+        if start <= last_end:
+            merged[-1] = (last_start, max(last_end, end))
+        else:
+            merged.append((start, end))
+    return merged
+
+
+def _apply_redactions(text: str, merged_spans: list[tuple[int, int]], redaction_char: str) -> str:
+    if not merged_spans:
+        return text
+    pieces: list[str] = []
+    cursor = 0
+    for start, end in merged_spans:
+        pieces.append(text[cursor:start])
+        pieces.append(redaction_char * (end - start))
+        cursor = end
+    pieces.append(text[cursor:])
+    return "".join(pieces)
+
+
+# ---------------------------------------------------------------------------
+# Default implementation
+# ---------------------------------------------------------------------------
+
+
+class ListBasedTextFilter:
+    """Deterministic `TextFilter`: normalized substring match against a term list.
+
+    `mode` controls what happens on a match:
+    - `FilterMode.REDACT` (default): matched spans in the *original* text
+      are replaced with `redaction_char` repeated to the matched span's
+      original length; `action` is REDACT if anything matched, else ALLOW.
+    - `FilterMode.REJECT`: `filtered_text` is returned unchanged but
+      `action` is REJECT if anything matched (callers should treat this as
+      "do not store/deliver"), else ALLOW.
+
+    An empty or whitespace-only string always returns ALLOW with no
+    matches -- there is nothing to filter.
+    """
+
+    def __init__(
+        self,
+        terms: Iterable[str] | None = None,
+        *,
+        mode: FilterMode = FilterMode.REDACT,
+        terms_path: Path | str | None = None,
+        redaction_char: str = "*",
+    ) -> None:
+        if terms is None:
+            terms = load_terms(terms_path)
+        # De-dupe while preserving order; drop blanks.
+        seen: dict[str, None] = {}
+        for t in terms:
+            t = t.strip()
+            if t:
+                seen.setdefault(t, None)
+        self._terms: tuple[str, ...] = tuple(seen)
+        # Pre-normalize once at construction; skip terms that normalize to
+        # nothing (e.g. a term that's pure punctuation).
+        self._normalized_terms: list[tuple[str, str]] = [
+            (normalized, original)
+            for original in self._terms
+            if (normalized := _normalize_term(original))
+        ]
+        self.mode = mode
+        self.redaction_char = redaction_char
+
+    def check(self, text: str) -> FilterResult:
+        if not text or not text.strip():
+            return FilterResult(action=FilterAction.ALLOW, filtered_text=text, matched_terms=())
+
+        normalized, index_map = _normalize(text)
+        if not normalized:
+            return FilterResult(action=FilterAction.ALLOW, filtered_text=text, matched_terms=())
+
+        spans: list[tuple[int, int, str]] = []
+        for normalized_term, original_term in self._normalized_terms:
+            start = 0
+            term_len = len(normalized_term)
+            while True:
+                idx = normalized.find(normalized_term, start)
+                if idx == -1:
+                    break
+                end = idx + term_len
+                orig_start = index_map[idx]
+                orig_end = index_map[end - 1] + 1
+                spans.append((orig_start, orig_end, original_term))
+                start = end  # non-overlapping: resume after this match
+
+        if not spans:
+            return FilterResult(action=FilterAction.ALLOW, filtered_text=text, matched_terms=())
+
+        spans.sort(key=lambda s: s[0])
+        matched_terms = tuple(dict.fromkeys(term for _, _, term in spans))
+
+        if self.mode is FilterMode.REJECT:
+            return FilterResult(action=FilterAction.REJECT, filtered_text=text, matched_terms=matched_terms)
+
+        merged = _merge_spans(spans)
+        filtered_text = _apply_redactions(text, merged, self.redaction_char)
+        return FilterResult(action=FilterAction.REDACT, filtered_text=filtered_text, matched_terms=matched_terms)
+
+
+def default_text_filter(mode: FilterMode = FilterMode.REDACT) -> ListBasedTextFilter:
+    """Convenience factory for the bundled default term list."""
+    return ListBasedTextFilter(mode=mode)

backend/app/services/text_filter_terms.json

@@ -0,0 +1,20 @@
+{
+  "_readme": "Default deterministic term list for app.services.text_filter.ListBasedTextFilter. This is a minimal, illustrative starter list (common mild-to-strong English profanity, no slurs) meant to be replaced/extended per-deployment -- swap this file, or pass an explicit `terms`/`terms_path` to the filter, rather than editing this list in place for production moderation policy.",
+  "terms": [
+    "fuck",
+    "shit",
+    "ass",
+    "asshole",
+    "bitch",
+    "bastard",
+    "damn",
+    "crap",
+    "dick",
+    "piss",
+    "slut",
+    "whore",
+    "cunt",
+    "douche",
+    "bullshit"
+  ]
+}

backend/app/services/wallet.py

@@ -0,0 +1,208 @@
+"""Wallet service: atomic credit/debit, row locking, and idempotency.
+
+docs/planning/economy.md US-1 (task 909e3e9a59af).
+"""
+
+from __future__ import annotations
+
+import logging
+from typing import Any
+
+from sqlalchemy import func, select
+from sqlalchemy.exc import IntegrityError
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.models.wallet import Transaction, TransactionType, Wallet
+
+logger = logging.getLogger(__name__)
+
+
+class InsufficientFundsError(Exception):
+    """Raised when a debit would cause wallet balance to drop below zero."""
+    pass
+
+
+class InvalidAmountError(ValueError):
+    """Raised when an invalid (non-positive) amount is supplied."""
+    pass
+
+
+class WalletService:
+    @staticmethod
+    async def get_or_create_wallet(
+        db: AsyncSession, user_id: int, for_update: bool = False
+    ) -> Wallet:
+        """Fetch existing wallet or lazily create one for user_id.
+
+        If for_update is True, locks the row with SELECT ... FOR UPDATE.
+        """
+        stmt = select(Wallet).where(Wallet.user_id == user_id)
+        if for_update:
+            stmt = stmt.with_for_update()
+
+        result = await db.execute(stmt)
+        wallet = result.scalar_one_or_none()
+        if wallet is not None:
+            return wallet
+
+        # If not found and not in update mode, create lazily
+        try:
+            new_wallet = Wallet(user_id=user_id, balance=0)
+            db.add(new_wallet)
+            await db.commit()
+            await db.refresh(new_wallet)
+
+            if for_update:
+                stmt_locked = select(Wallet).where(Wallet.id == new_wallet.id).with_for_update()
+                res = await db.execute(stmt_locked)
+                return res.scalar_one()
+
+            return new_wallet
+        except IntegrityError:
+            # Concurrent insert collision -- rollback and fetch the existing one
+            await db.rollback()
+            stmt = select(Wallet).where(Wallet.user_id == user_id)
+            if for_update:
+                stmt = stmt.with_for_update()
+            result = await db.execute(stmt)
+            return result.scalar_one()
+
+    @classmethod
+    async def credit(
+        cls,
+        db: AsyncSession,
+        user_id: int,
+        amount: int,
+        tx_type: TransactionType | str,
+        reference_type: str | None = None,
+        reference_id: str | None = None,
+        idempotency_key: str | None = None,
+        metadata: dict[str, Any] | None = None,
+        commit: bool = True,
+    ) -> tuple[Wallet, Transaction]:
+        """Credit a user's wallet atomically with row locking.
+
+        If an idempotency_key is provided and already exists, returns the original
+        outcome without double-crediting.
+        """
+        if amount <= 0:
+            raise InvalidAmountError("Credit amount must be strictly positive")
+
+        if isinstance(tx_type, str):
+            tx_type = TransactionType(tx_type)
+
+        # Check idempotency first
+        if idempotency_key:
+            stmt = select(Transaction).where(Transaction.idempotency_key == idempotency_key)
+            existing_tx = (await db.execute(stmt)).scalar_one_or_none()
+            if existing_tx is not None:
+                wallet = await cls.get_or_create_wallet(db, user_id, for_update=False)
+                return wallet, existing_tx
+
+        # Lock wallet row
+        wallet = await cls.get_or_create_wallet(db, user_id, for_update=True)
+        wallet.balance += amount
+
+        tx = Transaction(
+            wallet_id=wallet.id,
+            type=tx_type,
+            amount=amount,
+            balance_after=wallet.balance,
+            reference_type=reference_type,
+            reference_id=reference_id,
+            idempotency_key=idempotency_key,
+            metadata_json=metadata,
+        )
+        db.add(tx)
+        if commit:
+            await db.commit()
+            await db.refresh(wallet)
+            await db.refresh(tx)
+        else:
+            await db.flush()
+        return wallet, tx
+
+    @classmethod
+    async def debit(
+        cls,
+        db: AsyncSession,
+        user_id: int,
+        amount: int,
+        tx_type: TransactionType | str,
+        reference_type: str | None = None,
+        reference_id: str | None = None,
+        idempotency_key: str | None = None,
+        metadata: dict[str, Any] | None = None,
+        commit: bool = True,
+    ) -> tuple[Wallet, Transaction]:
+        """Debit a user's wallet atomically with row locking and balance check.
+
+        Raises InsufficientFundsError if wallet balance < amount.
+        If idempotency_key is provided and already exists, returns the original
+        outcome without double-debiting.
+        """
+        if amount <= 0:
+            raise InvalidAmountError("Debit amount must be strictly positive")
+
+        if isinstance(tx_type, str):
+            tx_type = TransactionType(tx_type)
+
+        # Check idempotency first
+        if idempotency_key:
+            stmt = select(Transaction).where(Transaction.idempotency_key == idempotency_key)
+            existing_tx = (await db.execute(stmt)).scalar_one_or_none()
+            if existing_tx is not None:
+                wallet = await cls.get_or_create_wallet(db, user_id, for_update=False)
+                return wallet, existing_tx
+
+        # Lock wallet row
+        wallet = await cls.get_or_create_wallet(db, user_id, for_update=True)
+        cur_balance = wallet.balance
+        if cur_balance < amount:
+            if commit:
+                await db.rollback()
+            raise InsufficientFundsError(
+                f"Insufficient funds: available {cur_balance}, required {amount}"
+            )
+
+        wallet.balance -= amount
+
+        tx = Transaction(
+            wallet_id=wallet.id,
+            type=tx_type,
+            amount=-amount,
+            balance_after=wallet.balance,
+            reference_type=reference_type,
+            reference_id=reference_id,
+            idempotency_key=idempotency_key,
+            metadata_json=metadata,
+        )
+        db.add(tx)
+        if commit:
+            await db.commit()
+            await db.refresh(wallet)
+            await db.refresh(tx)
+        else:
+            await db.flush()
+        return wallet, tx
+
+    @staticmethod
+    async def get_transactions(
+        db: AsyncSession, wallet_id: int, limit: int = 50, offset: int = 0
+    ) -> tuple[list[Transaction], int]:
+        """Fetch paged transactions for a wallet ordered newest-first, plus total count."""
+        count_stmt = select(func.count()).select_from(Transaction).where(Transaction.wallet_id == wallet_id)
+        total = (await db.execute(count_stmt)).scalar() or 0
+
+        stmt = (
+            select(Transaction)
+            .where(Transaction.wallet_id == wallet_id)
+            .order_by(Transaction.created_at.desc(), Transaction.id.desc())
+            .offset(offset)
+            .limit(limit)
+        )
+        res = await db.execute(stmt)
+        return list(res.scalars().all()), total
+
+
+wallet_service = WalletService()

backend/tests/conftest.py

@@ -1,18 +1,22 @@
-"""Shared pytest fixtures + hermetic-DB bootstrap.
+"""Shared pytest fixtures + hermetic-DB/Redis bootstrap.
 
 The integration tests hit a real Postgres (Postgres-specific types: JSONB,
-native ENUMs). To make ``cd backend && pytest`` work from a clean checkout
+native ENUMs) and, for presence tests, a real Redis (TTL semantics aren't
-with no manual setup, ``pytest_configure`` below brings up an ephemeral
+worth faking). To make ``cd backend && pytest`` work from a clean checkout
-Postgres via docker compose and runs the migrations IF ``DATABASE_URL`` is
+with no manual setup, ``pytest_configure`` below brings up ephemeral
-not already pointing at a reachable database. When it is (dev loop, or the
+Postgres/Redis containers via docker compose and runs the migrations IF
-checkpoint runner which stands the DB up itself), that path is skipped and
+``DATABASE_URL``/``REDIS_URL`` aren't already pointing at something
-the existing database is reused.
+reachable. When they are (dev loop, or the checkpoint runner which stands
+these up itself), that path is skipped and the existing services are
+reused.
 
-If Docker isn't available and no DB is reachable, the whole DB-backed suite
+If Docker isn't available and nothing is reachable, the whole
-is skipped with a clear message rather than erroring out 60+ times.
+DB/Redis-backed suite is skipped with a clear message rather than erroring
+out dozens of times.
 """
 
 import asyncio
+import hashlib
 import os
 import socket
 import subprocess
@@ -32,20 +36,54 @@ from app.main import app
 
 TEST_TABLES = (
     "avatar_loadouts", "assets",
+    # Profile (app/models/profile.py) -- both FK users.id, profile_favorites
+    # additionally FKs worlds.id; list explicitly for clarity/consistency.
+    "profile_favorites", "profiles",
     # world_chunk_revisions has no FK to worlds/world_chunks (world.md §4.7 /
     # world_persistence_impl.md §4.3, deliberate -- deleting a chunk or world
     # must not lose the audit trail), so it won't be cascade-truncated via
     # `worlds` the way world_rooms/world_chunks would be. List all three
     # explicitly rather than rely on cascade for some of them.
     "world_chunk_revisions", "world_chunks", "world_rooms",
-    "worlds", "sessions", "refresh_tokens", "users",
+    "worlds",
+    # Social graph (app/models/social.py) -- all three FK users with
+    # ON DELETE CASCADE, but list explicitly for clarity/consistency.
+    "friendships", "follows", "blocks",
+    # Chat (app/models/chat.py). message_reports.message_id is ON DELETE SET
+    # NULL (not CASCADE, deliberately -- see chat.py), so it wouldn't be
+    # reached by cascading a truncate of messages/conversations; list it
+    # explicitly along with the rest for clarity/consistency.
+    "message_reports", "messages", "conversation_participants", "conversations",
+    # Groups (app/models/groups.py). groups.owner_id is ON DELETE SET NULL
+    # (not CASCADE, deliberately -- see groups.py), so it wouldn't be reached
+    # by cascading a truncate of users; list it explicitly for clarity too.
+    "group_members", "groups",
+    # Economy (app/models/wallet.py, app/models/marketplace.py)
+    "purchases", "marketplace_listings", "catalog_items", "creator_balances",
+    "transactions", "wallets",
+    "sessions", "refresh_tokens", "users",
 )
 
 BACKEND_DIR = Path(__file__).resolve().parents[1]
-_COMPOSE_PROJECT = "agp-pytest"
-_EPHEMERAL_PG_PORT = 25432
 
-# Set by _ensure_database() when it starts a container it owns; torn down in
+# A hardcoded project name/port here would mean every concurrent checkout
+# running `pytest` (e.g. several Claude Agent-tool subagents, each in their
+# own ~/agp/workspace/task_<id> clone) fights over the exact same Docker
+# Compose project and host ports -- one run's pytest_unconfigure teardown
+# can yank the ephemeral Postgres out from under a completely unrelated
+# concurrent run, surfacing as "connection was closed in the middle of
+# operation" with no obvious cause. Confirmed live 2026-09-15 running 3
+# parallel subagents. Same root cause and fix pattern as the agent_core
+# workspace/Docker-Compose collision documented in project_agp memory --
+# derive both the project name and the port from a hash of the checkout
+# directory, so different concurrent checkouts land on different projects/
+# ports while the same checkout is stable across repeated runs.
+_WORKSPACE_HASH = hashlib.sha256(str(BACKEND_DIR.parent).encode()).hexdigest()[:10]
+_COMPOSE_PROJECT = f"agp-pytest-{_WORKSPACE_HASH}"
+_EPHEMERAL_PG_PORT = 25400 + (int(_WORKSPACE_HASH, 16) % 100)
+_EPHEMERAL_REDIS_PORT = 26300 + (int(_WORKSPACE_HASH, 16) % 100)
+
+# Set by pytest_configure() when it starts container(s) it owns; torn down in
 # pytest_unconfigure.
 _started_container = False
 _db_unavailable_reason: str | None = None
@@ -64,6 +102,11 @@ def _db_reachable(url: str) -> bool:
     return _port_open(parts.hostname or "localhost", parts.port or 5432)
 
 
+def _redis_reachable(url: str) -> bool:
+    parts = urlsplit(url)
+    return _port_open(parts.hostname or "localhost", parts.port or 6379)
+
+
 def _run(cmd: list[str], **kw) -> subprocess.CompletedProcess:
     return subprocess.run(cmd, cwd=BACKEND_DIR, capture_output=True, text=True, **kw)
 
@@ -71,14 +114,17 @@ def _run(cmd: list[str], **kw) -> subprocess.CompletedProcess:
 def pytest_configure(config):
     global _started_container, _db_unavailable_reason
 
-    if _db_reachable(settings.DATABASE_URL):
+    need_db = not _db_reachable(settings.DATABASE_URL)
-        return  # dev loop / checkpoint runner already provided one
+    need_redis = not _redis_reachable(settings.REDIS_URL)
+
+    if not need_db and not need_redis:
+        return  # dev loop / checkpoint runner already provided both
 
     if not _run(["docker", "--version"]).returncode == 0:
         _db_unavailable_reason = (
-            "no reachable DATABASE_URL and docker is unavailable -- run the "
+            "no reachable DATABASE_URL/REDIS_URL and docker is unavailable -- run "
-            "checkpoint suite (scripts/run_checkpoint_tests.py) or start Postgres "
+            "the checkpoint suite (scripts/run_checkpoint_tests.py) or start "
-            "manually"
+            "Postgres/Redis manually"
         )
         return
 
@@ -86,12 +132,16 @@ def pytest_configure(config):
     env["COMPOSE_PROJECT_NAME"] = _COMPOSE_PROJECT
     env["POSTGRES_HOST_PORT"] = str(_EPHEMERAL_PG_PORT)
     env["POSTGRES_PORT"] = str(_EPHEMERAL_PG_PORT)
-    up = _run(["docker", "compose", "up", "-d", "postgres"], env=env)
+    env["REDIS_HOST_PORT"] = str(_EPHEMERAL_REDIS_PORT)
+
+    services = [s for s, need in (("postgres", need_db), ("redis", need_redis)) if need]
+    up = _run(["docker", "compose", "up", "-d", *services], env=env)
     if up.returncode != 0:
-        _db_unavailable_reason = f"docker compose up postgres failed:\n{up.stderr[-800:]}"
+        _db_unavailable_reason = f"docker compose up {' '.join(services)} failed:\n{up.stderr[-800:]}"
         return
     _started_container = True
 
+    if need_db:
         for _ in range(30):
             r = _run(
                 ["docker", "compose", "exec", "-T", "postgres",
@@ -113,6 +163,24 @@ def pytest_configure(config):
                    env={**os.environ, "DATABASE_URL": url})
         if mig.returncode != 0:
             _db_unavailable_reason = f"alembic upgrade head failed:\n{mig.stderr[-800:]}"
+            return
+
+    if need_redis:
+        for _ in range(30):
+            r = _run(
+                ["docker", "compose", "exec", "-T", "redis", "redis-cli", "ping"],
+                env=env,
+            )
+            if r.returncode == 0 and "PONG" in r.stdout:
+                break
+            time.sleep(1)
+        else:
+            _db_unavailable_reason = "ephemeral Redis never became ready"
+            return
+
+        redis_url = f"redis://localhost:{_EPHEMERAL_REDIS_PORT}/0"
+        os.environ["REDIS_URL"] = redis_url
+        settings.REDIS_URL = redis_url
 
 
 def pytest_unconfigure(config):
@@ -122,6 +190,7 @@ def pytest_unconfigure(config):
     env["COMPOSE_PROJECT_NAME"] = _COMPOSE_PROJECT
     env["POSTGRES_HOST_PORT"] = str(_EPHEMERAL_PG_PORT)
     env["POSTGRES_PORT"] = str(_EPHEMERAL_PG_PORT)
+    env["REDIS_HOST_PORT"] = str(_EPHEMERAL_REDIS_PORT)
     _run(["docker", "compose", "down", "-v"], env=env)
 
 

backend/tests/test_chat_dm.py

@@ -0,0 +1,312 @@
+"""Integration tests for the DM chat router (app/routers/chat_dm.py):
+
+- POST /api/chat/dm/{user_id}/messages
+- GET  /api/chat/dm/{user_id}/messages
+- GET  /api/chat/dm/conversations
+
+The block-relationship router doesn't exist yet (sibling task), so blocks
+are inserted directly against the ``Block`` model, same pattern already
+used by ``tests/test_chat_models.py`` for direct model setup.
+"""
+
+import pytest
+from fastapi.testclient import TestClient
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import async_sessionmaker, create_async_engine
+from sqlalchemy.pool import NullPool
+
+from app import rate_limit
+from app.config import settings
+from app.main import app
+from app.models.social import Block
+
+
+def _register(client: TestClient, username: str) -> dict:
+    resp = client.post(
+        "/api/auth/register",
+        json={
+            "username": username,
+            "email": f"{username}@example.com",
+            "password": "secret123",
+            "date_of_birth": "1990-01-01",
+        },
+    )
+    assert resp.status_code == 201, resp.text
+    token = resp.json()["access_token"]
+    headers = {"Authorization": f"Bearer {token}"}
+    me = client.get("/api/users/me", headers=headers)
+    assert me.status_code == 200, me.text
+    return {"headers": headers, "id": me.json()["id"], "username": username}
+
+
+async def _insert_block(blocker_id: int, blocked_id: int) -> None:
+    engine = create_async_engine(settings.DATABASE_URL, poolclass=NullPool)
+    session_factory = async_sessionmaker(engine, expire_on_commit=False)
+    async with session_factory() as session:
+        session.add(Block(blocker_id=blocker_id, blocked_id=blocked_id))
+        await session.commit()
+    await engine.dispose()
+
+
+class TestSendAndRetrieve:
+    def test_send_then_fetch_history(self):
+        client = TestClient(app)
+        alice = _register(client, "dm_alice1")
+        bob = _register(client, "dm_bob1")
+
+        resp = client.post(
+            f"/api/chat/dm/{bob['id']}/messages",
+            json={"body": "hey bob"},
+            headers=alice["headers"],
+        )
+        assert resp.status_code == 201, resp.text
+        sent = resp.json()
+        assert sent["sender_id"] == alice["id"]
+        assert sent["recipient_id"] == bob["id"]
+        assert sent["body"] == "hey bob"
+        assert sent["filtered"] is False
+        assert sent["id"] is not None
+        assert sent["created_at"] is not None
+
+        hist_alice = client.get(f"/api/chat/dm/{bob['id']}/messages", headers=alice["headers"])
+        assert hist_alice.status_code == 200, hist_alice.text
+        msgs = hist_alice.json()["messages"]
+        assert len(msgs) == 1
+        assert msgs[0]["body"] == "hey bob"
+
+        hist_bob = client.get(f"/api/chat/dm/{alice['id']}/messages", headers=bob["headers"])
+        assert hist_bob.status_code == 200, hist_bob.text
+        assert len(hist_bob.json()["messages"]) == 1
+        assert hist_bob.json()["messages"][0]["body"] == "hey bob"
+
+    def test_cannot_message_self(self):
+        client = TestClient(app)
+        alice = _register(client, "dm_self1")
+        resp = client.post(
+            f"/api/chat/dm/{alice['id']}/messages",
+            json={"body": "hi me"},
+            headers=alice["headers"],
+        )
+        assert resp.status_code == 400
+
+    def test_target_user_must_exist(self):
+        client = TestClient(app)
+        alice = _register(client, "dm_noexist1")
+        resp = client.post(
+            "/api/chat/dm/999999999/messages",
+            json={"body": "hello?"},
+            headers=alice["headers"],
+        )
+        assert resp.status_code == 404
+
+    def test_requires_auth(self):
+        client = TestClient(app)
+        resp = client.post("/api/chat/dm/1/messages", json={"body": "hi"})
+        assert resp.status_code == 401
+
+    def test_history_pagination_cursor(self):
+        client = TestClient(app)
+        alice = _register(client, "dm_page_a")
+        bob = _register(client, "dm_page_b")
+
+        for i in range(5):
+            r = client.post(
+                f"/api/chat/dm/{bob['id']}/messages",
+                json={"body": f"msg {i}"},
+                headers=alice["headers"],
+            )
+            assert r.status_code == 201, r.text
+
+        page1 = client.get(
+            f"/api/chat/dm/{bob['id']}/messages",
+            params={"limit": 2},
+            headers=alice["headers"],
+        )
+        assert page1.status_code == 200
+        body1 = page1.json()
+        assert len(body1["messages"]) == 2
+        assert body1["messages"][0]["body"] == "msg 4"  # newest first
+        assert body1["next_cursor"] is not None
+
+        page2 = client.get(
+            f"/api/chat/dm/{bob['id']}/messages",
+            params={"limit": 2, "before": body1["next_cursor"]},
+            headers=alice["headers"],
+        )
+        assert page2.status_code == 200
+        body2 = page2.json()
+        assert [m["body"] for m in body2["messages"]] == ["msg 2", "msg 1"]
+
+    def test_no_conversation_yet_returns_empty_history(self):
+        client = TestClient(app)
+        alice = _register(client, "dm_empty_a")
+        bob = _register(client, "dm_empty_b")
+        resp = client.get(f"/api/chat/dm/{bob['id']}/messages", headers=alice["headers"])
+        assert resp.status_code == 200
+        assert resp.json() == {"messages": [], "next_cursor": None}
+
+
+class TestConversationList:
+    def test_lists_peer_last_message_and_unread_count(self):
+        client = TestClient(app)
+        alice = _register(client, "dm_conv_a")
+        bob = _register(client, "dm_conv_b")
+
+        client.post(
+            f"/api/chat/dm/{bob['id']}/messages",
+            json={"body": "first"},
+            headers=alice["headers"],
+        )
+        client.post(
+            f"/api/chat/dm/{bob['id']}/messages",
+            json={"body": "second"},
+            headers=alice["headers"],
+        )
+
+        convs_bob = client.get("/api/chat/dm/conversations", headers=bob["headers"])
+        assert convs_bob.status_code == 200, convs_bob.text
+        data = convs_bob.json()
+        assert data["total"] == 1
+        conv = data["conversations"][0]
+        assert conv["peer_id"] == alice["id"]
+        assert conv["peer_username"] == "dm_conv_a"
+        assert conv["last_message"]["body"] == "second"
+        assert conv["unread_count"] == 2  # bob hasn't read yet
+
+        # Bob reads the latest page -> unread resets to 0.
+        client.get(f"/api/chat/dm/{alice['id']}/messages", headers=bob["headers"])
+        convs_bob_after = client.get("/api/chat/dm/conversations", headers=bob["headers"])
+        assert convs_bob_after.json()["conversations"][0]["unread_count"] == 0
+
+        # Alice sent them, so her own unread count for this conversation is 0.
+        convs_alice = client.get("/api/chat/dm/conversations", headers=alice["headers"])
+        assert convs_alice.json()["conversations"][0]["unread_count"] == 0
+
+    def test_scoped_to_authenticated_user_only(self):
+        client = TestClient(app)
+        alice = _register(client, "dm_scope_a")
+        bob = _register(client, "dm_scope_b")
+        carol = _register(client, "dm_scope_c")
+
+        client.post(
+            f"/api/chat/dm/{bob['id']}/messages",
+            json={"body": "hi bob"},
+            headers=alice["headers"],
+        )
+
+        convs_carol = client.get("/api/chat/dm/conversations", headers=carol["headers"])
+        assert convs_carol.status_code == 200
+        assert convs_carol.json() == {"conversations": [], "total": 0}
+
+    def test_cannot_read_another_pairs_conversation(self):
+        """A user's history endpoint only ever resolves *their own* pairing
+        with the given peer id -- there is no conversation id in the URL an
+        outsider could guess/pass to read someone else's DMs."""
+        client = TestClient(app)
+        alice = _register(client, "dm_iso_a")
+        bob = _register(client, "dm_iso_b")
+        carol = _register(client, "dm_iso_c")
+
+        client.post(
+            f"/api/chat/dm/{bob['id']}/messages",
+            json={"body": "secret to bob"},
+            headers=alice["headers"],
+        )
+
+        # Carol asking for her "history with bob" gets her own (empty)
+        # conversation, never alice's.
+        resp = client.get(f"/api/chat/dm/{bob['id']}/messages", headers=carol["headers"])
+        assert resp.status_code == 200
+        assert resp.json()["messages"] == []
+
+
+class TestBlocking:
+    async def test_blocker_cannot_send_to_blocked(self):
+        client = TestClient(app)
+        alice = _register(client, "dm_block_a1")
+        bob = _register(client, "dm_block_b1")
+        await _insert_block(alice["id"], bob["id"])
+
+        resp = client.post(
+            f"/api/chat/dm/{bob['id']}/messages",
+            json={"body": "let me in"},
+            headers=alice["headers"],
+        )
+        assert resp.status_code == 403
+
+    async def test_blocked_cannot_send_to_blocker(self):
+        client = TestClient(app)
+        alice = _register(client, "dm_block_a2")
+        bob = _register(client, "dm_block_b2")
+        await _insert_block(alice["id"], bob["id"])
+
+        resp = client.post(
+            f"/api/chat/dm/{alice['id']}/messages",
+            json={"body": "please respond"},
+            headers=bob["headers"],
+        )
+        assert resp.status_code == 403
+
+
+class TestTextFilter:
+    def test_message_tripping_filter_is_redacted_and_flagged(self):
+        client = TestClient(app)
+        alice = _register(client, "dm_filter_a")
+        bob = _register(client, "dm_filter_b")
+
+        resp = client.post(
+            f"/api/chat/dm/{bob['id']}/messages",
+            json={"body": "you are a bastard"},
+            headers=alice["headers"],
+        )
+        assert resp.status_code == 201, resp.text
+        data = resp.json()
+        assert data["filtered"] is True
+        assert "bastard" not in data["body"]
+        assert "*" in data["body"]
+
+        # The stored/delivered copy is the redacted one, not the raw text.
+        hist = client.get(f"/api/chat/dm/{alice['id']}/messages", headers=bob["headers"])
+        assert hist.json()["messages"][0]["body"] == data["body"]
+
+    def test_clean_message_is_not_flagged(self):
+        client = TestClient(app)
+        alice = _register(client, "dm_clean_a")
+        bob = _register(client, "dm_clean_b")
+        resp = client.post(
+            f"/api/chat/dm/{bob['id']}/messages",
+            json={"body": "have a nice day"},
+            headers=alice["headers"],
+        )
+        assert resp.status_code == 201
+        assert resp.json()["filtered"] is False
+        assert resp.json()["body"] == "have a nice day"
+
+
+class TestRateLimit:
+    @pytest.fixture(autouse=True)
+    def _enable_rate_limiting(self):
+        prev = settings.RATE_LIMIT_ENABLED
+        settings.RATE_LIMIT_ENABLED = True
+        rate_limit.reset_all()
+        yield
+        rate_limit.reset_all()
+        settings.RATE_LIMIT_ENABLED = prev
+
+    def test_send_rate_limit_exceeded_returns_429(self):
+        client = TestClient(app)
+        alice = _register(client, "dm_rl_a")
+        bob = _register(client, "dm_rl_b")
+
+        codes = []
+        for i in range(25):
+            r = client.post(
+                f"/api/chat/dm/{bob['id']}/messages",
+                json={"body": f"spam {i}"},
+                headers=alice["headers"],
+            )
+            codes.append(r.status_code)
+
+        assert codes[:20] == [201] * 20
+        assert 429 in codes[20:]
+        assert codes[-1] == 429

backend/tests/test_chat_models.py

@@ -0,0 +1,344 @@
+"""Model-level tests for chat: conversations, messages, message reports.
+
+app/models/chat.py / alembic/versions/0008_add_chat_tables.py
+(docs/planning/social.md US-4). This is the models+migration task only --
+there are no API endpoints yet (sibling tasks own filtering, rate limiting,
+and the routers), so these tests exercise the ORM models and the real
+Postgres constraints directly rather than going through HTTP.
+"""
+
+import pytest
+from fastapi.testclient import TestClient
+from sqlalchemy import delete, select
+from sqlalchemy.exc import IntegrityError
+from sqlalchemy.ext.asyncio import async_sessionmaker, create_async_engine
+from sqlalchemy.pool import NullPool
+
+from app.config import settings
+from app.main import app
+from app.models.chat import (
+    Conversation,
+    ConversationParticipant,
+    Message,
+    MessageReport,
+    ReportStatus,
+)
+from app.models.user import User
+from app.models.world import World
+
+
+def _register(client: TestClient, username: str) -> int:
+    resp = client.post(
+        "/api/auth/register",
+        json={
+            "username": username,
+            "email": f"{username}@example.com",
+            "password": "secret123",
+            "date_of_birth": "1990-01-01",
+        },
+    )
+    assert resp.status_code == 201, resp.text
+    headers = {"Authorization": f"Bearer {resp.json()['access_token']}"}
+    me = client.get("/api/users/me", headers=headers)
+    assert me.status_code == 200, me.text
+    return me.json()["id"]
+
+
+def _session_factory():
+    engine = create_async_engine(settings.DATABASE_URL, poolclass=NullPool)
+    return engine, async_sessionmaker(engine, expire_on_commit=False)
+
+
+class TestConversationCreation:
+    async def test_create_conversation_with_participants_and_messages(self):
+        client = TestClient(app)
+        a = _register(client, "chat_conv_a")
+        b = _register(client, "chat_conv_b")
+
+        engine, factory = _session_factory()
+        try:
+            lo, hi = sorted((a, b))
+            async with factory() as session:
+                convo = Conversation(user_a_id=lo, user_b_id=hi)
+                session.add(convo)
+                await session.flush()
+                session.add_all(
+                    [
+                        ConversationParticipant(conversation_id=convo.id, user_id=a),
+                        ConversationParticipant(conversation_id=convo.id, user_id=b),
+                    ]
+                )
+                session.add(
+                    Message(sender_id=a, conversation_id=convo.id, body="hi there")
+                )
+                await session.commit()
+                convo_id = convo.id
+
+            async with factory() as session:
+                participants = (
+                    await session.execute(
+                        select(ConversationParticipant).where(
+                            ConversationParticipant.conversation_id == convo_id
+                        )
+                    )
+                ).scalars().all()
+                messages = (
+                    await session.execute(
+                        select(Message).where(Message.conversation_id == convo_id)
+                    )
+                ).scalars().all()
+                assert len(participants) == 2
+                assert len(messages) == 1
+                assert messages[0].sender_id == a
+                assert messages[0].filtered is False
+        finally:
+            await engine.dispose()
+
+    async def test_duplicate_pair_rejected(self):
+        client = TestClient(app)
+        a = _register(client, "chat_uq_a")
+        b = _register(client, "chat_uq_b")
+        lo, hi = sorted((a, b))
+
+        engine, factory = _session_factory()
+        try:
+            async with factory() as session:
+                session.add(Conversation(user_a_id=lo, user_b_id=hi))
+                await session.commit()
+
+            async with factory() as session:
+                session.add(Conversation(user_a_id=lo, user_b_id=hi))
+                with pytest.raises(IntegrityError):
+                    await session.commit()
+        finally:
+            await engine.dispose()
+
+    async def test_unordered_pair_rejected_by_check_constraint(self):
+        client = TestClient(app)
+        a = _register(client, "chat_ck_a")
+        b = _register(client, "chat_ck_b")
+        lo, hi = sorted((a, b))
+
+        engine, factory = _session_factory()
+        try:
+            async with factory() as session:
+                # Reversed order violates ck_conversations_ordered_pair.
+                session.add(Conversation(user_a_id=hi, user_b_id=lo))
+                with pytest.raises(IntegrityError):
+                    await session.commit()
+        finally:
+            await engine.dispose()
+
+
+class TestWorldRoomChat:
+    async def test_world_message_has_null_conversation(self):
+        client = TestClient(app)
+        owner = _register(client, "chat_world_owner")
+
+        engine, factory = _session_factory()
+        try:
+            async with factory() as session:
+                world = World(name="Chat Test World", owner_id=owner)
+                session.add(world)
+                await session.flush()
+                msg = Message(sender_id=owner, world_id=world.id, body="hello world")
+                session.add(msg)
+                await session.commit()
+                world_id = world.id
+
+            async with factory() as session:
+                rows = (
+                    await session.execute(
+                        select(Message).where(Message.world_id == world_id)
+                    )
+                ).scalars().all()
+                assert len(rows) == 1
+                assert rows[0].conversation_id is None
+                assert rows[0].room_id is None
+        finally:
+            await engine.dispose()
+
+
+class TestMessageReports:
+    async def test_create_report_defaults_to_open(self):
+        client = TestClient(app)
+        sender = _register(client, "chat_rpt_sender")
+        reporter = _register(client, "chat_rpt_reporter")
+
+        engine, factory = _session_factory()
+        try:
+            async with factory() as session:
+                world = World(name="Report World", owner_id=sender)
+                session.add(world)
+                await session.flush()
+                msg = Message(sender_id=sender, world_id=world.id, body="bad words")
+                session.add(msg)
+                await session.flush()
+                report = MessageReport(
+                    message_id=msg.id, reporter_id=reporter, reason="spam"
+                )
+                session.add(report)
+                await session.commit()
+                report_id = report.id
+
+            async with factory() as session:
+                report = await session.get(MessageReport, report_id)
+                assert report.status == ReportStatus.OPEN
+                assert report.moderator_id is None
+                assert report.resolved_at is None
+        finally:
+            await engine.dispose()
+
+
+class TestCascadeDelete:
+    async def test_deleting_conversation_deletes_participants_and_messages(self):
+        client = TestClient(app)
+        a = _register(client, "chat_cd_conv_a")
+        b = _register(client, "chat_cd_conv_b")
+        lo, hi = sorted((a, b))
+
+        engine, factory = _session_factory()
+        try:
+            async with factory() as session:
+                convo = Conversation(user_a_id=lo, user_b_id=hi)
+                session.add(convo)
+                await session.flush()
+                session.add_all(
+                    [
+                        ConversationParticipant(conversation_id=convo.id, user_id=a),
+                        ConversationParticipant(conversation_id=convo.id, user_id=b),
+                    ]
+                )
+                session.add(Message(sender_id=a, conversation_id=convo.id, body="bye"))
+                await session.commit()
+                convo_id = convo.id
+
+            async with factory() as session:
+                # Core delete against the conversations table directly, so
+                # the real ON DELETE CASCADE does the work (not the ORM).
+                await session.execute(
+                    delete(Conversation).where(Conversation.id == convo_id)
+                )
+                await session.commit()
+
+            async with factory() as session:
+                participants = (
+                    await session.execute(
+                        select(ConversationParticipant).where(
+                            ConversationParticipant.conversation_id == convo_id
+                        )
+                    )
+                ).scalars().all()
+                messages = (
+                    await session.execute(
+                        select(Message).where(Message.conversation_id == convo_id)
+                    )
+                ).scalars().all()
+                assert participants == []
+                assert messages == []
+        finally:
+            await engine.dispose()
+
+    async def test_deleting_user_removes_conversation_but_keeps_report_and_message_id_null(self):
+        """Deleting a conversation participant cascades away the whole DM
+        (conversation + participants + messages -- there's no third party
+        left to care about the history). Deleting the sender of a
+        world-chat message, by contrast, must NOT delete the message or its
+        report -- sender_id is SET NULL and message_reports.message_id
+        follows the message (also SET NULL, never CASCADE) so the audit
+        trail survives account deletion."""
+        client = TestClient(app)
+        a = _register(client, "chat_cd_user_a")
+        b = _register(client, "chat_cd_user_b")
+        reporter = _register(client, "chat_cd_user_reporter")
+        lo, hi = sorted((a, b))
+
+        engine, factory = _session_factory()
+        try:
+            async with factory() as session:
+                convo = Conversation(user_a_id=lo, user_b_id=hi)
+                session.add(convo)
+                await session.flush()
+                session.add_all(
+                    [
+                        ConversationParticipant(conversation_id=convo.id, user_id=a),
+                        ConversationParticipant(conversation_id=convo.id, user_id=b),
+                    ]
+                )
+                session.add(Message(sender_id=a, conversation_id=convo.id, body="dm"))
+
+                world = World(name="Sender Delete World", owner_id=b)
+                session.add(world)
+                await session.flush()
+                world_msg = Message(sender_id=a, world_id=world.id, body="world chat")
+                session.add(world_msg)
+                await session.flush()
+                report = MessageReport(
+                    message_id=world_msg.id, reporter_id=reporter, reason="rude"
+                )
+                session.add(report)
+                await session.commit()
+                convo_id = convo.id
+                world_msg_id = world_msg.id
+                report_id = report.id
+
+            async with factory() as session:
+                # Delete `a`: participant in the DM (cascades the whole
+                # conversation) and sender of the world message (SET NULL).
+                await session.execute(delete(User).where(User.id == a))
+                await session.commit()
+
+            async with factory() as session:
+                convo_row = await session.get(Conversation, convo_id)
+                dm_messages = (
+                    await session.execute(
+                        select(Message).where(Message.conversation_id == convo_id)
+                    )
+                ).scalars().all()
+                world_msg = await session.get(Message, world_msg_id)
+                report = await session.get(MessageReport, report_id)
+
+                assert convo_row is None
+                assert dm_messages == []
+                # World message survives with sender_id nulled out.
+                assert world_msg is not None
+                assert world_msg.sender_id is None
+                assert world_msg.body == "world chat"
+                # Report still points at the surviving message.
+                assert report is not None
+                assert report.message_id == world_msg_id
+        finally:
+            await engine.dispose()
+
+    async def test_deleting_message_nulls_report_message_id(self):
+        client = TestClient(app)
+        sender = _register(client, "chat_cd_msg_sender")
+        reporter = _register(client, "chat_cd_msg_reporter")
+
+        engine, factory = _session_factory()
+        try:
+            async with factory() as session:
+                world = World(name="Msg Delete World", owner_id=sender)
+                session.add(world)
+                await session.flush()
+                msg = Message(sender_id=sender, world_id=world.id, body="to be removed")
+                session.add(msg)
+                await session.flush()
+                report = MessageReport(
+                    message_id=msg.id, reporter_id=reporter, reason="spam"
+                )
+                session.add(report)
+                await session.commit()
+                msg_id = msg.id
+                report_id = report.id
+
+            async with factory() as session:
+                await session.execute(delete(Message).where(Message.id == msg_id))
+                await session.commit()
+
+            async with factory() as session:
+                report = await session.get(MessageReport, report_id)
+                assert report is not None
+                assert report.message_id is None
+        finally:
+            await engine.dispose()

backend/tests/test_chat_reports.py

@@ -0,0 +1,201 @@
+"""Integration tests for message reporting and moderation queue:
+- POST /api/chat/messages/{message_id}/report
+- GET  /api/moderation/reports
+- POST /api/moderation/reports/{id}/resolve
+"""
+
+import pytest
+from fastapi.testclient import TestClient
+
+from app.main import app
+
+
+def _register(client: TestClient, username: str) -> dict:
+    resp = client.post(
+        "/api/auth/register",
+        json={
+            "username": username,
+            "email": f"{username}@example.com",
+            "password": "secret123",
+            "date_of_birth": "1990-01-01",
+        },
+    )
+    assert resp.status_code == 201, resp.text
+    token = resp.json()["access_token"]
+    headers = {"Authorization": f"Bearer {token}"}
+    me = client.get("/api/users/me", headers=headers)
+    assert me.status_code == 200, me.text
+    return {"headers": headers, "id": me.json()["id"], "username": username}
+
+
+def _send_dm(client: TestClient, sender: dict, recipient: dict, text: str = "hello") -> int:
+    resp = client.post(
+        f"/api/chat/dm/{recipient['id']}/messages",
+        headers=sender["headers"],
+        json={"body": text},
+    )
+    assert resp.status_code == 201, resp.text
+    return resp.json()["id"]
+
+
+class TestReportMessage:
+    def test_report_message_success(self):
+        client = TestClient(app)
+        alice = _register(client, "rep_alice1")
+        bob = _register(client, "rep_bob1")
+
+        msg_id = _send_dm(client, alice, bob, "spam message")
+
+        resp = client.post(
+            f"/api/chat/messages/{msg_id}/report",
+            headers=bob["headers"],
+            json={"reason": "Contains spam", "category": "spam"},
+        )
+        assert resp.status_code == 201, resp.text
+        data = resp.json()
+        assert data["message_id"] == msg_id
+        assert data["reporter_id"] == bob["id"]
+        assert data["status"] == "open"
+        assert "[spam] Contains spam" in data["reason"]
+
+    def test_duplicate_report_rejected(self):
+        client = TestClient(app)
+        alice = _register(client, "rep_alice2")
+        bob = _register(client, "rep_bob2")
+
+        msg_id = _send_dm(client, alice, bob, "bad message")
+
+        resp1 = client.post(
+            f"/api/chat/messages/{msg_id}/report",
+            headers=bob["headers"],
+            json={"reason": "offensive"},
+        )
+        assert resp1.status_code == 201
+
+        resp2 = client.post(
+            f"/api/chat/messages/{msg_id}/report",
+            headers=bob["headers"],
+            json={"reason": "offensive again"},
+        )
+        assert resp2.status_code == 409
+
+    def test_report_nonexistent_message_404(self):
+        client = TestClient(app)
+        bob = _register(client, "rep_bob3")
+
+        resp = client.post(
+            "/api/chat/messages/999999/report",
+            headers=bob["headers"],
+            json={"reason": "ghost"},
+        )
+        assert resp.status_code == 404
+
+    def test_report_requires_auth(self):
+        client = TestClient(app)
+        resp = client.post("/api/chat/messages/1/report", json={"reason": "no auth"})
+        assert resp.status_code == 401
+
+
+class TestModerationQueue:
+    def test_non_moderator_cannot_access_queue(self):
+        client = TestClient(app)
+        regular_user = _register(client, "rep_regular1")
+
+        resp = client.get("/api/moderation/reports", headers=regular_user["headers"])
+        assert resp.status_code == 403
+
+    def test_moderator_can_list_reports(self):
+        client = TestClient(app)
+        alice = _register(client, "rep_alice4")
+        bob = _register(client, "rep_bob4")
+        admin = _register(client, "admin_list")
+
+        msg_id = _send_dm(client, alice, bob, "something to report")
+        client.post(
+            f"/api/chat/messages/{msg_id}/report",
+            headers=bob["headers"],
+            json={"reason": "needs review"},
+        )
+
+        resp = client.get("/api/moderation/reports", headers=admin["headers"])
+        assert resp.status_code == 200, resp.text
+        reports = resp.json()
+        assert len(reports) >= 1
+        assert any(r["message_id"] == msg_id for r in reports)
+
+    def test_moderator_resolve_dismiss(self):
+        client = TestClient(app)
+        alice = _register(client, "rep_alice5")
+        bob = _register(client, "rep_bob5")
+        admin = _register(client, "admin_dismiss")
+
+        msg_id = _send_dm(client, alice, bob, "benign message")
+        rep_resp = client.post(
+            f"/api/chat/messages/{msg_id}/report",
+            headers=bob["headers"],
+            json={"reason": "false alarm"},
+        )
+        report_id = rep_resp.json()["id"]
+
+        resolve_resp = client.post(
+            f"/api/moderation/reports/{report_id}/resolve",
+            headers=admin["headers"],
+            json={"action": "dismiss", "notes": "No violation found"},
+        )
+        assert resolve_resp.status_code == 200, resolve_resp.text
+        data = resolve_resp.json()
+        assert data["report_id"] == report_id
+        assert data["status"] == "dismissed"
+        assert data["action_taken"] == "dismiss"
+        assert data["moderator_id"] == admin["id"]
+
+    def test_moderator_resolve_remove(self):
+        client = TestClient(app)
+        alice = _register(client, "rep_alice6")
+        bob = _register(client, "rep_bob6")
+        admin = _register(client, "admin_remove")
+
+        msg_id = _send_dm(client, alice, bob, "offensive content")
+        rep_resp = client.post(
+            f"/api/chat/messages/{msg_id}/report",
+            headers=bob["headers"],
+            json={"reason": "hate speech"},
+        )
+        report_id = rep_resp.json()["id"]
+
+        resolve_resp = client.post(
+            f"/api/moderation/reports/{report_id}/resolve",
+            headers=admin["headers"],
+            json={"action": "remove", "notes": "Content removed"},
+        )
+        assert resolve_resp.status_code == 200
+        assert resolve_resp.json()["status"] == "resolved"
+
+        # The message is removed from conversation history
+        hist = client.get(f"/api/chat/dm/{bob['id']}/messages", headers=alice["headers"])
+        assert all(m["id"] != msg_id for m in hist.json()["messages"])
+
+    def test_moderator_resolve_ban(self):
+        client = TestClient(app)
+        bad_user = _register(client, "bad_actor")
+        victim = _register(client, "rep_victim")
+        admin_auth = _register(client, "admin_ban")
+
+        msg_id = _send_dm(client, bad_user, victim, "terrible violation")
+        rep_resp = client.post(
+            f"/api/chat/messages/{msg_id}/report",
+            headers=victim["headers"],
+            json={"reason": "malicious user"},
+        )
+        report_id = rep_resp.json()["id"]
+
+        resolve_resp = client.post(
+            f"/api/moderation/reports/{report_id}/resolve",
+            headers=admin_auth["headers"],
+            json={"action": "ban", "notes": "Banned malicious user"},
+        )
+        assert resolve_resp.status_code == 200
+
+        # Attempting to use bad_user's token fails with 403 inactive account
+        bad_me = client.get("/api/users/me", headers=bad_user["headers"])
+        assert bad_me.status_code == 403

backend/tests/test_chat_world.py

@@ -0,0 +1,246 @@
+"""Integration tests for in-experience world/room chat:
+- POST /api/chat/world/{world_id}/messages
+- GET  /api/chat/world/{world_id}/messages
+- POST /api/chat/room/{room_id}/messages
+- GET  /api/chat/room/{room_id}/messages
+"""
+
+import pytest
+from fastapi.testclient import TestClient
+
+from app.main import app
+
+
+def _register(client: TestClient, username: str) -> dict:
+    resp = client.post(
+        "/api/auth/register",
+        json={
+            "username": username,
+            "email": f"{username}@example.com",
+            "password": "secret123",
+            "date_of_birth": "1990-01-01",
+        },
+    )
+    assert resp.status_code == 201, resp.text
+    token = resp.json()["access_token"]
+    headers = {"Authorization": f"Bearer {token}"}
+    me = client.get("/api/users/me", headers=headers)
+    assert me.status_code == 200, me.text
+    return {"headers": headers, "id": me.json()["id"], "username": username}
+
+
+def _make_world(client: TestClient, headers: dict, visibility: str = "public") -> int:
+    r = client.post("/api/worlds/", headers=headers, json={"name": "TestWorld", "visibility": visibility})
+    assert r.status_code == 201, r.text
+    return r.json()["id"]
+
+
+def _make_friends(client: TestClient, user_a: dict, user_b: dict) -> None:
+    req = client.post("/api/friends/requests", json={"user_id": user_b["id"]}, headers=user_a["headers"])
+    assert req.status_code == 201, req.text
+    req_id = req.json()["id"]
+    acc = client.post(f"/api/friends/requests/{req_id}/accept", headers=user_b["headers"])
+    assert acc.status_code == 200, acc.text
+
+
+class TestWorldChat:
+    def test_send_and_get_world_message(self):
+        client = TestClient(app)
+        alice = _register(client, "wch_alice1")
+        bob = _register(client, "wch_bob1")
+
+        world_id = _make_world(client, alice["headers"], visibility="public")
+
+        # Bob posts to Alice's public world
+        post_resp = client.post(
+            f"/api/chat/world/{world_id}/messages",
+            headers=bob["headers"],
+            json={"body": "Hello world from Bob!"},
+        )
+        assert post_resp.status_code == 201, post_resp.text
+        msg_data = post_resp.json()
+        assert msg_data["world_id"] == world_id
+        assert msg_data["room_id"] is None
+        assert msg_data["sender_id"] == bob["id"]
+        assert msg_data["body"] == "Hello world from Bob!"
+        assert msg_data["filtered"] is False
+        assert msg_data["author"]["username"] == "wch_bob1"
+        assert msg_data["author"]["id"] == bob["id"]
+
+        # Alice gets world chat history
+        get_resp = client.get(
+            f"/api/chat/world/{world_id}/messages",
+            headers=alice["headers"],
+        )
+        assert get_resp.status_code == 200, get_resp.text
+        history = get_resp.json()
+        assert len(history["messages"]) == 1
+        assert history["messages"][0]["id"] == msg_data["id"]
+        assert history["messages"][0]["author"]["username"] == "wch_bob1"
+
+    def test_room_scoped_messages(self):
+        client = TestClient(app)
+        alice = _register(client, "wch_alice2")
+        world_id = _make_world(client, alice["headers"])
+
+        # Fetch auto-created main room
+        rooms_resp = client.get(f"/api/worlds/{world_id}/rooms", headers=alice["headers"])
+        assert rooms_resp.status_code == 200, rooms_resp.text
+        rooms = rooms_resp.json()
+        assert len(rooms) >= 1
+        room_id = rooms[0]["id"]
+
+        # Post directly via room endpoint
+        post_room = client.post(
+            f"/api/chat/room/{room_id}/messages",
+            headers=alice["headers"],
+            json={"body": "Message in room"},
+        )
+        assert post_room.status_code == 201, post_room.text
+        msg_data = post_room.json()
+        assert msg_data["world_id"] == world_id
+        assert msg_data["room_id"] == room_id
+        assert msg_data["body"] == "Message in room"
+
+        # Get room history
+        get_room = client.get(
+            f"/api/chat/room/{room_id}/messages",
+            headers=alice["headers"],
+        )
+        assert get_room.status_code == 200, get_room.text
+        messages = get_room.json()["messages"]
+        assert len(messages) == 1
+        assert messages[0]["id"] == msg_data["id"]
+
+        # Also visible when querying world history with room_id filter
+        get_world_room = client.get(
+            f"/api/chat/world/{world_id}/messages?room_id={room_id}",
+            headers=alice["headers"],
+        )
+        assert get_world_room.status_code == 200, get_world_room.text
+        assert len(get_world_room.json()["messages"]) == 1
+
+    def test_visibility_access_control(self):
+        client = TestClient(app)
+        alice = _register(client, "wch_alice3")
+        bob = _register(client, "wch_bob3")
+        charlie = _register(client, "wch_charlie3")
+
+        # Private world: only Alice
+        priv_world_id = _make_world(client, alice["headers"], visibility="private")
+
+        # Bob cannot send or read
+        bob_send = client.post(
+            f"/api/chat/world/{priv_world_id}/messages",
+            headers=bob["headers"],
+            json={"body": "Trying to trespass"},
+        )
+        assert bob_send.status_code == 403, bob_send.text
+
+        bob_read = client.get(
+            f"/api/chat/world/{priv_world_id}/messages",
+            headers=bob["headers"],
+        )
+        assert bob_read.status_code == 403, bob_read.text
+
+        # Alice (owner) can send and read
+        alice_send = client.post(
+            f"/api/chat/world/{priv_world_id}/messages",
+            headers=alice["headers"],
+            json={"body": "My private sanctum"},
+        )
+        assert alice_send.status_code == 201, alice_send.text
+
+        # Friends-only world
+        fr_world_id = _make_world(client, alice["headers"], visibility="friends_only")
+        _make_friends(client, alice, bob)
+
+        # Bob (friend) can post
+        bob_fr_send = client.post(
+            f"/api/chat/world/{fr_world_id}/messages",
+            headers=bob["headers"],
+            json={"body": "Hello friend!"},
+        )
+        assert bob_fr_send.status_code == 201, bob_fr_send.text
+
+        # Charlie (not friend) cannot post or read
+        charlie_send = client.post(
+            f"/api/chat/world/{fr_world_id}/messages",
+            headers=charlie["headers"],
+            json={"body": "Can I join?"},
+        )
+        assert charlie_send.status_code == 403, charlie_send.text
+
+        charlie_read = client.get(
+            f"/api/chat/world/{fr_world_id}/messages",
+            headers=charlie["headers"],
+        )
+        assert charlie_read.status_code == 403, charlie_read.text
+
+    def test_not_found_validation(self):
+        client = TestClient(app)
+        alice = _register(client, "wch_alice4")
+
+        # Non-existent world
+        res = client.post(
+            "/api/chat/world/999999/messages",
+            headers=alice["headers"],
+            json={"body": "Ghost world"},
+        )
+        assert res.status_code == 404, res.text
+
+        # Non-existent room
+        world_id = _make_world(client, alice["headers"])
+        res2 = client.post(
+            f"/api/chat/world/{world_id}/messages",
+            headers=alice["headers"],
+            json={"body": "Ghost room", "room_id": 999999},
+        )
+        assert res2.status_code == 404, res2.text
+
+    def test_text_filtering_in_world_chat(self):
+        client = TestClient(app)
+        alice = _register(client, "wch_alice5")
+        world_id = _make_world(client, alice["headers"])
+
+        # Default filter redacts forbidden words
+        res = client.post(
+            f"/api/chat/world/{world_id}/messages",
+            headers=alice["headers"],
+            json={"body": "you are a bastard"},
+        )
+        assert res.status_code == 201, res.text
+        data = res.json()
+        assert data["filtered"] is True
+        assert "bastard" not in data["body"]
+        assert "*" in data["body"]
+
+    def test_pagination_and_next_cursor(self):
+        client = TestClient(app)
+        alice = _register(client, "wch_alice6")
+        world_id = _make_world(client, alice["headers"])
+
+        for i in range(5):
+            r = client.post(
+                f"/api/chat/world/{world_id}/messages",
+                headers=alice["headers"],
+                json={"body": f"Msg {i}"},
+            )
+            assert r.status_code == 201
+
+        page1 = client.get(
+            f"/api/chat/world/{world_id}/messages?limit=2",
+            headers=alice["headers"],
+        ).json()
+        assert len(page1["messages"]) == 2
+        assert page1["next_cursor"] is not None
+        assert page1["messages"][0]["body"] == "Msg 4"
+        assert page1["messages"][1]["body"] == "Msg 3"
+
+        page2 = client.get(
+            f"/api/chat/world/{world_id}/messages?limit=2&before={page1['next_cursor']}",
+            headers=alice["headers"],
+        ).json()
+        assert len(page2["messages"]) == 2
+        assert page2["messages"][0]["body"] == "Msg 2"
+        assert page2["messages"][1]["body"] == "Msg 1"

backend/tests/test_group_models.py

@@ -0,0 +1,258 @@
+"""Model-level tests for groups: groups and group_members.
+
+app/models/groups.py / alembic/versions/0009_add_group_tables.py
+(docs/planning/social.md US-5). This is the models+migration task only --
+there are no API endpoints yet (a sibling task, "Groups API", owns
+create/join/leave/role authorization and the group page endpoint), so these
+tests exercise the ORM models and the real Postgres constraints directly
+rather than going through HTTP.
+"""
+
+import pytest
+from fastapi.testclient import TestClient
+from sqlalchemy import delete, select
+from sqlalchemy.exc import IntegrityError
+from sqlalchemy.ext.asyncio import async_sessionmaker, create_async_engine
+from sqlalchemy.pool import NullPool
+
+from app.config import settings
+from app.main import app
+from app.models.groups import Group, GroupMember, GroupRole
+from app.models.user import User
+
+
+def _register(client: TestClient, username: str) -> int:
+    resp = client.post(
+        "/api/auth/register",
+        json={
+            "username": username,
+            "email": f"{username}@example.com",
+            "password": "secret123",
+            "date_of_birth": "1990-01-01",
+        },
+    )
+    assert resp.status_code == 201, resp.text
+    headers = {"Authorization": f"Bearer {resp.json()['access_token']}"}
+    me = client.get("/api/users/me", headers=headers)
+    assert me.status_code == 200, me.text
+    return me.json()["id"]
+
+
+def _session_factory():
+    engine = create_async_engine(settings.DATABASE_URL, poolclass=NullPool)
+    return engine, async_sessionmaker(engine, expire_on_commit=False)
+
+
+class TestGroupCreationAndRoles:
+    async def test_create_group_with_members_of_different_roles(self):
+        client = TestClient(app)
+        owner = _register(client, "grp_role_owner")
+        admin = _register(client, "grp_role_admin")
+        member = _register(client, "grp_role_member")
+
+        engine, factory = _session_factory()
+        try:
+            async with factory() as session:
+                group = Group(name="Explorers", description="We explore worlds", owner_id=owner)
+                session.add(group)
+                await session.flush()
+                session.add_all(
+                    [
+                        GroupMember(group_id=group.id, user_id=owner, role=GroupRole.OWNER),
+                        GroupMember(group_id=group.id, user_id=admin, role=GroupRole.ADMIN),
+                        GroupMember(group_id=group.id, user_id=member, role=GroupRole.MEMBER),
+                    ]
+                )
+                await session.commit()
+                group_id = group.id
+
+            async with factory() as session:
+                fetched = await session.get(Group, group_id)
+                members = (
+                    await session.execute(
+                        select(GroupMember).where(GroupMember.group_id == group_id)
+                    )
+                ).scalars().all()
+                by_user = {m.user_id: m.role for m in members}
+                assert fetched.owner_id == owner
+                assert len(members) == 3
+                assert by_user[owner] == GroupRole.OWNER
+                assert by_user[admin] == GroupRole.ADMIN
+                assert by_user[member] == GroupRole.MEMBER
+        finally:
+            await engine.dispose()
+
+    async def test_membership_role_defaults_to_member(self):
+        client = TestClient(app)
+        owner = _register(client, "grp_default_owner")
+        joiner = _register(client, "grp_default_joiner")
+
+        engine, factory = _session_factory()
+        try:
+            async with factory() as session:
+                group = Group(name="Defaults", owner_id=owner)
+                session.add(group)
+                await session.flush()
+                session.add(GroupMember(group_id=group.id, user_id=joiner))
+                await session.commit()
+                group_id = group.id
+
+            async with factory() as session:
+                gm = (
+                    await session.execute(
+                        select(GroupMember).where(
+                            GroupMember.group_id == group_id, GroupMember.user_id == joiner
+                        )
+                    )
+                ).scalar_one()
+                assert gm.role == GroupRole.MEMBER
+        finally:
+            await engine.dispose()
+
+
+class TestUniqueMembershipConstraint:
+    async def test_duplicate_membership_rejected(self):
+        client = TestClient(app)
+        owner = _register(client, "grp_uq_owner")
+        member = _register(client, "grp_uq_member")
+
+        engine, factory = _session_factory()
+        try:
+            async with factory() as session:
+                group = Group(name="Uniqueness", owner_id=owner)
+                session.add(group)
+                await session.flush()
+                session.add(GroupMember(group_id=group.id, user_id=member))
+                await session.commit()
+                group_id = group.id
+
+            async with factory() as session:
+                session.add(GroupMember(group_id=group_id, user_id=member))
+                with pytest.raises(IntegrityError):
+                    await session.commit()
+        finally:
+            await engine.dispose()
+
+
+class TestCascadeDelete:
+    async def test_deleting_group_deletes_members(self):
+        client = TestClient(app)
+        owner = _register(client, "grp_cd_group_owner")
+        member = _register(client, "grp_cd_group_member")
+
+        engine, factory = _session_factory()
+        try:
+            async with factory() as session:
+                group = Group(name="To Delete", owner_id=owner)
+                session.add(group)
+                await session.flush()
+                session.add_all(
+                    [
+                        GroupMember(group_id=group.id, user_id=owner, role=GroupRole.OWNER),
+                        GroupMember(group_id=group.id, user_id=member),
+                    ]
+                )
+                await session.commit()
+                group_id = group.id
+
+            async with factory() as session:
+                # Core delete against groups directly, so the real ON DELETE
+                # CASCADE does the work (not the ORM).
+                await session.execute(delete(Group).where(Group.id == group_id))
+                await session.commit()
+
+            async with factory() as session:
+                members = (
+                    await session.execute(
+                        select(GroupMember).where(GroupMember.group_id == group_id)
+                    )
+                ).scalars().all()
+                assert members == []
+        finally:
+            await engine.dispose()
+
+    async def test_deleting_member_user_removes_only_their_membership(self):
+        client = TestClient(app)
+        owner = _register(client, "grp_cd_user_owner")
+        member = _register(client, "grp_cd_user_member")
+
+        engine, factory = _session_factory()
+        try:
+            async with factory() as session:
+                group = Group(name="Membership Cascade", owner_id=owner)
+                session.add(group)
+                await session.flush()
+                session.add_all(
+                    [
+                        GroupMember(group_id=group.id, user_id=owner, role=GroupRole.OWNER),
+                        GroupMember(group_id=group.id, user_id=member),
+                    ]
+                )
+                await session.commit()
+                group_id = group.id
+
+            async with factory() as session:
+                await session.execute(delete(User).where(User.id == member))
+                await session.commit()
+
+            async with factory() as session:
+                remaining = (
+                    await session.execute(
+                        select(GroupMember).where(GroupMember.group_id == group_id)
+                    )
+                ).scalars().all()
+                # Only the deleted member's row is gone; the group and the
+                # owner's membership survive.
+                assert len(remaining) == 1
+                assert remaining[0].user_id == owner
+
+                group = await session.get(Group, group_id)
+                assert group is not None
+                assert group.owner_id == owner
+        finally:
+            await engine.dispose()
+
+    async def test_deleting_owner_survives_with_owner_id_null(self):
+        """Deleting the owner's account must not delete the group or its
+        other members -- only ``owner_id`` is nulled out (SET NULL), per the
+        module docstring in app/models/groups.py."""
+        client = TestClient(app)
+        owner = _register(client, "grp_cd_owner_owner")
+        member = _register(client, "grp_cd_owner_member")
+
+        engine, factory = _session_factory()
+        try:
+            async with factory() as session:
+                group = Group(name="Survives Owner Deletion", owner_id=owner)
+                session.add(group)
+                await session.flush()
+                session.add_all(
+                    [
+                        GroupMember(group_id=group.id, user_id=owner, role=GroupRole.OWNER),
+                        GroupMember(group_id=group.id, user_id=member),
+                    ]
+                )
+                await session.commit()
+                group_id = group.id
+
+            async with factory() as session:
+                await session.execute(delete(User).where(User.id == owner))
+                await session.commit()
+
+            async with factory() as session:
+                group = await session.get(Group, group_id)
+                assert group is not None
+                assert group.owner_id is None
+                assert group.name == "Survives Owner Deletion"
+
+                # The owner's own membership row is gone (user_id CASCADE),
+                # but the other member's row survives untouched.
+                members = (
+                    await session.execute(
+                        select(GroupMember).where(GroupMember.group_id == group_id)
+                    )
+                ).scalars().all()
+                assert len(members) == 1
+                assert members[0].user_id == member
+        finally:
+            await engine.dispose()

backend/tests/test_groups_api.py

@@ -0,0 +1,437 @@
+"""Integration tests for the Groups API router (app/routers/groups.py).
+
+app/models/groups.py owns the schema (see test_group_models.py); this
+covers create/join/leave, role authorization, ownership transfer, and the
+group page's member-list privacy.
+"""
+
+from fastapi.testclient import TestClient
+
+from app.main import app
+
+
+def _register(client: TestClient, username: str) -> dict:
+    resp = client.post(
+        "/api/auth/register",
+        json={
+            "username": username,
+            "email": f"{username}@example.com",
+            "password": "secret123",
+            "date_of_birth": "1990-01-01",
+        },
+    )
+    assert resp.status_code == 201, resp.text
+    token = resp.json()["access_token"]
+    headers = {"Authorization": f"Bearer {token}"}
+    me = client.get("/api/users/me", headers=headers)
+    assert me.status_code == 200, me.text
+    return {"headers": headers, "id": me.json()["id"], "username": username}
+
+
+def _create_group(client: TestClient, headers: dict, name: str, description: str | None = None) -> dict:
+    resp = client.post(
+        "/api/groups",
+        json={"name": name, "description": description},
+        headers=headers,
+    )
+    assert resp.status_code == 201, resp.text
+    return resp.json()
+
+
+class TestCreateGroup:
+    def test_create_makes_creator_owner(self):
+        client = TestClient(app)
+        owner = _register(client, "grp_api_create_owner")
+
+        group = _create_group(client, owner["headers"], "Explorers", "We explore worlds")
+        assert group["name"] == "Explorers"
+        assert group["description"] == "We explore worlds"
+        assert group["owner_id"] == owner["id"]
+        assert group["member_count"] == 1
+        assert len(group["members"]) == 1
+        assert group["members"][0]["user_id"] == owner["id"]
+        assert group["members"][0]["role"] == "owner"
+
+    def test_requires_auth(self):
+        client = TestClient(app)
+        resp = client.post("/api/groups", json={"name": "No Auth"})
+        assert resp.status_code == 401
+
+    def test_blank_name_rejected(self):
+        client = TestClient(app)
+        owner = _register(client, "grp_api_blank_name")
+        resp = client.post("/api/groups", json={"name": "   "}, headers=owner["headers"])
+        assert resp.status_code == 422
+
+    def test_name_over_max_length_rejected(self):
+        client = TestClient(app)
+        owner = _register(client, "grp_api_long_name")
+        resp = client.post(
+            "/api/groups", json={"name": "x" * 101}, headers=owner["headers"]
+        )
+        assert resp.status_code == 422
+
+
+class TestGroupPage:
+    def test_get_group_page_shows_members_and_roles_no_private_fields(self):
+        client = TestClient(app)
+        owner = _register(client, "grp_api_page_owner")
+        member = _register(client, "grp_api_page_member")
+
+        group = _create_group(client, owner["headers"], "Page Group")
+        client.post(f"/api/groups/{group['id']}/join", headers=member["headers"])
+
+        resp = client.get(f"/api/groups/{group['id']}", headers=member["headers"])
+        assert resp.status_code == 200, resp.text
+        body = resp.json()
+        assert body["name"] == "Page Group"
+        assert body["member_count"] == 2
+        by_user = {m["user_id"]: m for m in body["members"]}
+        assert by_user[owner["id"]]["role"] == "owner"
+        assert by_user[member["id"]]["role"] == "member"
+        assert by_user[member["id"]]["username"] == member["username"]
+
+        # No private User fields (email, hashed_password, etc.) leak.
+        for m in body["members"]:
+            assert set(m.keys()) == {"user_id", "username", "role", "joined_at"}
+
+    def test_get_nonexistent_group_is_404(self):
+        client = TestClient(app)
+        user = _register(client, "grp_api_404")
+        resp = client.get("/api/groups/999999999", headers=user["headers"])
+        assert resp.status_code == 404
+
+
+class TestJoinLeave:
+    def test_join_is_idempotent(self):
+        client = TestClient(app)
+        owner = _register(client, "grp_api_join_owner")
+        joiner = _register(client, "grp_api_join_joiner")
+        group = _create_group(client, owner["headers"], "Join Group")
+
+        r1 = client.post(f"/api/groups/{group['id']}/join", headers=joiner["headers"])
+        assert r1.status_code == 200, r1.text
+        r2 = client.post(f"/api/groups/{group['id']}/join", headers=joiner["headers"])
+        assert r2.status_code == 200, r2.text
+        assert r1.json()["role"] == r2.json()["role"] == "member"
+
+        page = client.get(f"/api/groups/{group['id']}", headers=owner["headers"]).json()
+        assert page["member_count"] == 2  # not 3 -- duplicate join didn't add a row
+
+    def test_leave_removes_membership(self):
+        client = TestClient(app)
+        owner = _register(client, "grp_api_leave_owner")
+        member = _register(client, "grp_api_leave_member")
+        group = _create_group(client, owner["headers"], "Leave Group")
+        client.post(f"/api/groups/{group['id']}/join", headers=member["headers"])
+
+        resp = client.post(f"/api/groups/{group['id']}/leave", headers=member["headers"])
+        assert resp.status_code == 200, resp.text
+
+        page = client.get(f"/api/groups/{group['id']}", headers=owner["headers"]).json()
+        assert page["member_count"] == 1
+        assert all(m["user_id"] != member["id"] for m in page["members"])
+
+    def test_owner_cannot_leave_without_transfer(self):
+        client = TestClient(app)
+        owner = _register(client, "grp_api_owner_leave")
+        group = _create_group(client, owner["headers"], "Owner Leave Group")
+
+        resp = client.post(f"/api/groups/{group['id']}/leave", headers=owner["headers"])
+        assert resp.status_code == 409, resp.text
+
+    def test_leave_when_not_a_member_is_404(self):
+        client = TestClient(app)
+        owner = _register(client, "grp_api_notmember_owner")
+        stranger = _register(client, "grp_api_notmember_stranger")
+        group = _create_group(client, owner["headers"], "Not A Member Group")
+
+        resp = client.post(f"/api/groups/{group['id']}/leave", headers=stranger["headers"])
+        assert resp.status_code == 404
+
+
+class TestRoleAuthorization:
+    def test_owner_can_promote_and_demote(self):
+        client = TestClient(app)
+        owner = _register(client, "grp_api_role_owner")
+        member = _register(client, "grp_api_role_member")
+        group = _create_group(client, owner["headers"], "Role Group")
+        client.post(f"/api/groups/{group['id']}/join", headers=member["headers"])
+
+        promote = client.post(
+            f"/api/groups/{group['id']}/members/{member['id']}/role",
+            json={"role": "admin"},
+            headers=owner["headers"],
+        )
+        assert promote.status_code == 200, promote.text
+        assert promote.json()["role"] == "admin"
+
+        demote = client.post(
+            f"/api/groups/{group['id']}/members/{member['id']}/role",
+            json={"role": "member"},
+            headers=owner["headers"],
+        )
+        assert demote.status_code == 200, demote.text
+        assert demote.json()["role"] == "member"
+
+    def test_plain_member_cannot_promote(self):
+        client = TestClient(app)
+        owner = _register(client, "grp_api_noauth_owner")
+        member = _register(client, "grp_api_noauth_member")
+        other = _register(client, "grp_api_noauth_other")
+        group = _create_group(client, owner["headers"], "No Auth Promote Group")
+        client.post(f"/api/groups/{group['id']}/join", headers=member["headers"])
+        client.post(f"/api/groups/{group['id']}/join", headers=other["headers"])
+
+        resp = client.post(
+            f"/api/groups/{group['id']}/members/{other['id']}/role",
+            json={"role": "admin"},
+            headers=member["headers"],
+        )
+        assert resp.status_code == 403
+
+    def test_admin_cannot_promote_or_demote(self):
+        """Only the owner may change roles -- admins cannot, per spec."""
+        client = TestClient(app)
+        owner = _register(client, "grp_api_adminauth_owner")
+        admin = _register(client, "grp_api_adminauth_admin")
+        other = _register(client, "grp_api_adminauth_other")
+        group = _create_group(client, owner["headers"], "Admin Cannot Promote Group")
+        client.post(f"/api/groups/{group['id']}/join", headers=admin["headers"])
+        client.post(f"/api/groups/{group['id']}/join", headers=other["headers"])
+        client.post(
+            f"/api/groups/{group['id']}/members/{admin['id']}/role",
+            json={"role": "admin"},
+            headers=owner["headers"],
+        )
+
+        resp = client.post(
+            f"/api/groups/{group['id']}/members/{other['id']}/role",
+            json={"role": "admin"},
+            headers=admin["headers"],
+        )
+        assert resp.status_code == 403
+
+    def test_plain_member_cannot_delete_group(self):
+        client = TestClient(app)
+        owner = _register(client, "grp_api_nodelete_owner")
+        member = _register(client, "grp_api_nodelete_member")
+        group = _create_group(client, owner["headers"], "No Delete Group")
+        client.post(f"/api/groups/{group['id']}/join", headers=member["headers"])
+
+        resp = client.delete(f"/api/groups/{group['id']}", headers=member["headers"])
+        assert resp.status_code == 403
+
+    def test_admin_cannot_delete_group(self):
+        client = TestClient(app)
+        owner = _register(client, "grp_api_admindelete_owner")
+        admin = _register(client, "grp_api_admindelete_admin")
+        group = _create_group(client, owner["headers"], "Admin No Delete Group")
+        client.post(f"/api/groups/{group['id']}/join", headers=admin["headers"])
+        client.post(
+            f"/api/groups/{group['id']}/members/{admin['id']}/role",
+            json={"role": "admin"},
+            headers=owner["headers"],
+        )
+
+        resp = client.delete(f"/api/groups/{group['id']}", headers=admin["headers"])
+        assert resp.status_code == 403
+
+    def test_plain_member_cannot_transfer_ownership(self):
+        client = TestClient(app)
+        owner = _register(client, "grp_api_notransfer_owner")
+        member = _register(client, "grp_api_notransfer_member")
+        group = _create_group(client, owner["headers"], "No Transfer Group")
+        client.post(f"/api/groups/{group['id']}/join", headers=member["headers"])
+
+        resp = client.post(
+            f"/api/groups/{group['id']}/transfer",
+            json={"new_owner_id": member["id"]},
+            headers=member["headers"],
+        )
+        assert resp.status_code == 403
+
+    def test_cannot_set_role_to_owner_via_role_endpoint(self):
+        client = TestClient(app)
+        owner = _register(client, "grp_api_noownerrole_owner")
+        member = _register(client, "grp_api_noownerrole_member")
+        group = _create_group(client, owner["headers"], "No Owner Role Group")
+        client.post(f"/api/groups/{group['id']}/join", headers=member["headers"])
+
+        resp = client.post(
+            f"/api/groups/{group['id']}/members/{member['id']}/role",
+            json={"role": "owner"},
+            headers=owner["headers"],
+        )
+        assert resp.status_code == 422
+
+
+class TestOwnershipTransfer:
+    def test_transfer_moves_ownership_and_demotes_old_owner(self):
+        client = TestClient(app)
+        owner = _register(client, "grp_api_xfer_owner")
+        member = _register(client, "grp_api_xfer_member")
+        group = _create_group(client, owner["headers"], "Transfer Group")
+        client.post(f"/api/groups/{group['id']}/join", headers=member["headers"])
+
+        resp = client.post(
+            f"/api/groups/{group['id']}/transfer",
+            json={"new_owner_id": member["id"]},
+            headers=owner["headers"],
+        )
+        assert resp.status_code == 200, resp.text
+        body = resp.json()
+        assert body["owner_id"] == member["id"]
+        by_user = {m["user_id"]: m for m in body["members"]}
+        assert by_user[member["id"]]["role"] == "owner"
+        assert by_user[owner["id"]]["role"] == "admin"
+
+        # Exactly one owner remains.
+        owners = [m for m in body["members"] if m["role"] == "owner"]
+        assert len(owners) == 1
+
+        # Old owner can now leave (no longer the owner).
+        leave = client.post(f"/api/groups/{group['id']}/leave", headers=owner["headers"])
+        assert leave.status_code == 200, leave.text
+
+        # New owner cannot leave without transferring again.
+        leave2 = client.post(f"/api/groups/{group['id']}/leave", headers=member["headers"])
+        assert leave2.status_code == 409
+
+    def test_transfer_target_must_be_a_member(self):
+        client = TestClient(app)
+        owner = _register(client, "grp_api_xfernonmember_owner")
+        stranger = _register(client, "grp_api_xfernonmember_stranger")
+        group = _create_group(client, owner["headers"], "Transfer Nonmember Group")
+
+        resp = client.post(
+            f"/api/groups/{group['id']}/transfer",
+            json={"new_owner_id": stranger["id"]},
+            headers=owner["headers"],
+        )
+        assert resp.status_code == 404
+
+    def test_transfer_to_self_rejected(self):
+        client = TestClient(app)
+        owner = _register(client, "grp_api_xferself_owner")
+        group = _create_group(client, owner["headers"], "Transfer Self Group")
+
+        resp = client.post(
+            f"/api/groups/{group['id']}/transfer",
+            json={"new_owner_id": owner["id"]},
+            headers=owner["headers"],
+        )
+        assert resp.status_code == 400
+
+
+class TestUpdateGroup:
+    def test_owner_can_update_name_and_description(self):
+        client = TestClient(app)
+        owner = _register(client, "grp_api_update_owner")
+        group = _create_group(client, owner["headers"], "Old Name", "Old desc")
+
+        resp = client.patch(
+            f"/api/groups/{group['id']}",
+            json={"name": "New Name", "description": "New desc"},
+            headers=owner["headers"],
+        )
+        assert resp.status_code == 200, resp.text
+        assert resp.json()["name"] == "New Name"
+        assert resp.json()["description"] == "New desc"
+
+    def test_admin_can_update(self):
+        client = TestClient(app)
+        owner = _register(client, "grp_api_adminupdate_owner")
+        admin = _register(client, "grp_api_adminupdate_admin")
+        group = _create_group(client, owner["headers"], "Admin Update Group")
+        client.post(f"/api/groups/{group['id']}/join", headers=admin["headers"])
+        client.post(
+            f"/api/groups/{group['id']}/members/{admin['id']}/role",
+            json={"role": "admin"},
+            headers=owner["headers"],
+        )
+
+        resp = client.patch(
+            f"/api/groups/{group['id']}",
+            json={"name": "Updated By Admin"},
+            headers=admin["headers"],
+        )
+        assert resp.status_code == 200, resp.text
+        assert resp.json()["name"] == "Updated By Admin"
+
+    def test_plain_member_cannot_update(self):
+        client = TestClient(app)
+        owner = _register(client, "grp_api_noupdate_owner")
+        member = _register(client, "grp_api_noupdate_member")
+        group = _create_group(client, owner["headers"], "No Update Group")
+        client.post(f"/api/groups/{group['id']}/join", headers=member["headers"])
+
+        resp = client.patch(
+            f"/api/groups/{group['id']}",
+            json={"name": "Hacked Name"},
+            headers=member["headers"],
+        )
+        assert resp.status_code == 403
+
+    def test_non_member_cannot_update(self):
+        client = TestClient(app)
+        owner = _register(client, "grp_api_strangernoupdate_owner")
+        stranger = _register(client, "grp_api_strangernoupdate_stranger")
+        group = _create_group(client, owner["headers"], "Stranger No Update Group")
+
+        resp = client.patch(
+            f"/api/groups/{group['id']}",
+            json={"name": "Hacked Name"},
+            headers=stranger["headers"],
+        )
+        assert resp.status_code == 403
+
+
+class TestDeleteGroup:
+    def test_owner_can_delete(self):
+        client = TestClient(app)
+        owner = _register(client, "grp_api_delete_owner")
+        group = _create_group(client, owner["headers"], "Delete Group")
+
+        resp = client.delete(f"/api/groups/{group['id']}", headers=owner["headers"])
+        assert resp.status_code == 204, resp.text
+
+        after = client.get(f"/api/groups/{group['id']}", headers=owner["headers"])
+        assert after.status_code == 404
+
+
+class TestListGroups:
+    def test_list_all_groups_paginated(self):
+        client = TestClient(app)
+        owner = _register(client, "grp_api_list_owner")
+        _create_group(client, owner["headers"], "List Group A")
+        _create_group(client, owner["headers"], "List Group B")
+
+        resp = client.get("/api/groups", params={"limit": 1}, headers=owner["headers"])
+        assert resp.status_code == 200, resp.text
+        body = resp.json()
+        assert len(body["groups"]) == 1
+        assert body["total"] >= 2
+
+    def test_list_mine_only_returns_own_groups(self):
+        client = TestClient(app)
+        owner = _register(client, "grp_api_listmine_owner")
+        other_owner = _register(client, "grp_api_listmine_other")
+        mine = _create_group(client, owner["headers"], "Mine Group")
+        _create_group(client, other_owner["headers"], "Not Mine Group")
+
+        resp = client.get("/api/groups", params={"mine": True}, headers=owner["headers"])
+        assert resp.status_code == 200, resp.text
+        ids = [g["id"] for g in resp.json()["groups"]]
+        assert mine["id"] in ids
+        assert all(
+            g["id"] != mine["id"] or g["owner_id"] == owner["id"]
+            for g in resp.json()["groups"]
+        )
+        # The other owner's group must not appear.
+        other_group_ids = [
+            g["id"] for g in client.get(
+                "/api/groups", params={"mine": True}, headers=other_owner["headers"]
+            ).json()["groups"]
+        ]
+        assert mine["id"] not in other_group_ids

backend/tests/test_marketplace_api.py

@@ -0,0 +1,167 @@
+"""Integration tests for Marketplace Listings API.
+
+docs/planning/economy.md US-3 (task f51c7d95e237).
+"""
+
+import pytest
+from fastapi.testclient import TestClient
+
+from app.main import app
+
+
+def _register(client: TestClient, username: str) -> tuple[int, dict[str, str]]:
+    resp = client.post(
+        "/api/auth/register",
+        json={
+            "username": username,
+            "email": f"{username}@example.com",
+            "password": "secret123",
+            "date_of_birth": "1990-01-01",
+        },
+    )
+    assert resp.status_code == 201, resp.text
+    token = resp.json()["access_token"]
+    headers = {"Authorization": f"Bearer {token}"}
+    me = client.get("/api/users/me", headers=headers)
+    assert me.status_code == 200, me.text
+    return me.json()["id"], headers
+
+
+def test_catalog_items_and_listings_crud():
+    client = TestClient(app)
+    uid1, h1 = _register(client, "mkt_user_1")
+    uid2, h2 = _register(client, "mkt_user_2")
+
+    # 1. Create catalog item by user 1
+    resp = client.post(
+        "/api/marketplace/items",
+        headers=h1,
+        json={
+            "name": "Wizard Hat",
+            "description": "A pointy blue hat with stars",
+            "item_type": "avatar_item",
+            "metadata_json": {"color": "blue", "rarity": "rare"},
+        },
+    )
+    assert resp.status_code == 201, resp.text
+    item_data = resp.json()
+    assert item_data["name"] == "Wizard Hat"
+    assert item_data["owner_id"] == uid1
+    item_id = item_data["id"]
+
+    # 2. List catalog items
+    resp = client.get("/api/marketplace/items", headers=h1, params={"mine": "true"})
+    assert resp.status_code == 200
+    my_items = resp.json()
+    assert len(my_items) >= 1
+    assert any(i["id"] == item_id for i in my_items)
+
+    resp = client.get("/api/marketplace/items", headers=h2, params={"mine": "true"})
+    assert resp.status_code == 200
+    assert not any(i["id"] == item_id for i in resp.json())
+
+    # 3. User 2 tries to list User 1's item -> 403
+    resp = client.post(
+        "/api/marketplace/listings",
+        headers=h2,
+        json={
+            "catalog_item_id": item_id,
+            "price": 100,
+        },
+    )
+    assert resp.status_code == 403, resp.text
+
+    # Invalid price <= 0 -> 422
+    resp = client.post(
+        "/api/marketplace/listings",
+        headers=h1,
+        json={
+            "catalog_item_id": item_id,
+            "price": 0,
+        },
+    )
+    assert resp.status_code == 422
+
+    # 4. User 1 successfully lists item
+    resp = client.post(
+        "/api/marketplace/listings",
+        headers=h1,
+        json={
+            "catalog_item_id": item_id,
+            "price": 250,
+        },
+    )
+    assert resp.status_code == 201, resp.text
+    listing = resp.json()
+    assert listing["price"] == 250
+    assert listing["seller_id"] == uid1
+    assert listing["status"] == "active"
+    assert listing["catalog_item"]["name"] == "Wizard Hat"
+    listing_id = listing["id"]
+
+    # 5. Search / browse listings
+    resp = client.get("/api/marketplace/listings", params={"q": "Wizard"})
+    assert resp.status_code == 200, resp.text
+    data = resp.json()
+    assert data["total"] >= 1
+    assert any(l["id"] == listing_id for l in data["listings"])
+
+    # Filter by item_type
+    resp = client.get("/api/marketplace/listings", params={"item_type": "avatar_item"})
+    assert resp.status_code == 200
+    assert any(l["id"] == listing_id for l in resp.json()["listings"])
+
+    resp = client.get("/api/marketplace/listings", params={"item_type": "experience_pass"})
+    assert resp.status_code == 200
+    assert not any(l["id"] == listing_id for l in resp.json()["listings"])
+
+    # Price range filter
+    resp = client.get("/api/marketplace/listings", params={"min_price": 300})
+    assert resp.status_code == 200
+    assert not any(l["id"] == listing_id for l in resp.json()["listings"])
+
+    resp = client.get("/api/marketplace/listings", params={"max_price": 260})
+    assert resp.status_code == 200
+    assert any(l["id"] == listing_id for l in resp.json()["listings"])
+
+    # 6. Listing detail
+    resp = client.get(f"/api/marketplace/listings/{listing_id}")
+    assert resp.status_code == 200
+    assert resp.json()["id"] == listing_id
+
+    # 7. Update listing
+    # User 2 cannot update User 1's listing
+    resp = client.patch(
+        f"/api/marketplace/listings/{listing_id}",
+        headers=h2,
+        json={"price": 500},
+    )
+    assert resp.status_code == 403
+
+    # User 1 updates price
+    resp = client.patch(
+        f"/api/marketplace/listings/{listing_id}",
+        headers=h1,
+        json={"price": 350},
+    )
+    assert resp.status_code == 200
+    assert resp.json()["price"] == 350
+
+    # 8. Delist listing
+    # User 2 cannot delist
+    resp = client.delete(f"/api/marketplace/listings/{listing_id}", headers=h2)
+    assert resp.status_code == 403
+
+    # User 1 delists
+    resp = client.delete(f"/api/marketplace/listings/{listing_id}", headers=h1)
+    assert resp.status_code == 204
+
+    # Now detail shows delisted
+    resp = client.get(f"/api/marketplace/listings/{listing_id}")
+    assert resp.status_code == 200
+    assert resp.json()["status"] == "delisted"
+
+    # Default search only shows active
+    resp = client.get("/api/marketplace/listings")
+    assert resp.status_code == 200
+    assert not any(l["id"] == listing_id for l in resp.json()["listings"])

backend/tests/test_marketplace_models.py

@@ -0,0 +1,175 @@
+"""Model-level integration tests for Marketplace tables.
+
+docs/planning/economy.md US-3, US-4 (task 166836d55365).
+"""
+
+import pytest
+from fastapi.testclient import TestClient
+from sqlalchemy import select
+from sqlalchemy.exc import IntegrityError
+from sqlalchemy.ext.asyncio import async_sessionmaker, create_async_engine
+from sqlalchemy.pool import NullPool
+
+from app.config import settings
+from app.main import app
+from app.models.marketplace import (
+    CatalogItem,
+    CreatorBalance,
+    ItemType,
+    ListingStatus,
+    MarketplaceListing,
+    Purchase,
+    PurchaseStatus,
+)
+
+
+def _register(client: TestClient, username: str) -> int:
+    resp = client.post(
+        "/api/auth/register",
+        json={
+            "username": username,
+            "email": f"{username}@example.com",
+            "password": "secret123",
+            "date_of_birth": "1990-01-01",
+        },
+    )
+    assert resp.status_code == 201, resp.text
+    headers = {"Authorization": f"Bearer {resp.json()['access_token']}"}
+    me = client.get("/api/users/me", headers=headers)
+    assert me.status_code == 200, me.text
+    return me.json()["id"]
+
+
+def _session_factory():
+    engine = create_async_engine(settings.DATABASE_URL, poolclass=NullPool)
+    return engine, async_sessionmaker(engine, expire_on_commit=False)
+
+
+@pytest.mark.asyncio
+async def test_catalog_item_and_listing_creation():
+    client = TestClient(app)
+    seller_id = _register(client, "market_seller_1")
+    engine, sf = _session_factory()
+    try:
+        async with sf() as session:
+            item = CatalogItem(
+                owner_id=seller_id,
+                item_type=ItemType.avatar_item,
+                name="Cyber Wings",
+                description="Glow in the dark wings",
+                metadata_json={"slot": "back"},
+            )
+            session.add(item)
+            await session.commit()
+            await session.refresh(item)
+
+            assert item.id is not None
+            assert item.name == "Cyber Wings"
+
+            listing = MarketplaceListing(
+                catalog_item_id=item.id,
+                seller_id=seller_id,
+                price=250,
+                status=ListingStatus.active,
+            )
+            session.add(listing)
+            await session.commit()
+            await session.refresh(listing)
+
+            assert listing.id is not None
+            assert listing.price == 250
+            assert listing.status == ListingStatus.active
+    finally:
+        await engine.dispose()
+
+
+@pytest.mark.asyncio
+async def test_listing_price_positive_constraint():
+    client = TestClient(app)
+    seller_id = _register(client, "market_seller_2")
+    engine, sf = _session_factory()
+    try:
+        async with sf() as session:
+            item = CatalogItem(
+                owner_id=seller_id,
+                item_type=ItemType.asset,
+                name="Free Prop",
+            )
+            session.add(item)
+            await session.commit()
+            await session.refresh(item)
+
+            bad_listing = MarketplaceListing(
+                catalog_item_id=item.id,
+                seller_id=seller_id,
+                price=0,  # Must be > 0
+            )
+            session.add(bad_listing)
+            with pytest.raises(IntegrityError):
+                await session.commit()
+    finally:
+        await engine.dispose()
+
+
+@pytest.mark.asyncio
+async def test_creator_balance_uniqueness_and_constraints():
+    client = TestClient(app)
+    creator_id = _register(client, "market_creator_1")
+    engine, sf = _session_factory()
+    try:
+        async with sf() as session:
+            cb1 = CreatorBalance(user_id=creator_id, available=100, pending=50, lifetime_earned=150)
+            session.add(cb1)
+            await session.commit()
+            await session.refresh(cb1)
+
+            assert cb1.available == 100
+            assert cb1.pending == 50
+            assert cb1.lifetime_earned == 150
+
+        # Unique user_id constraint
+        async with sf() as session:
+            cb2 = CreatorBalance(user_id=creator_id)
+            session.add(cb2)
+            with pytest.raises(IntegrityError):
+                await session.commit()
+    finally:
+        await engine.dispose()
+
+
+@pytest.mark.asyncio
+async def test_purchase_record_creation():
+    client = TestClient(app)
+    seller_id = _register(client, "market_seller_3")
+    buyer_id = _register(client, "market_buyer_3")
+    engine, sf = _session_factory()
+    try:
+        async with sf() as session:
+            item = CatalogItem(owner_id=seller_id, item_type=ItemType.asset, name="Sword Prop")
+            session.add(item)
+            await session.commit()
+            await session.refresh(item)
+
+            listing = MarketplaceListing(catalog_item_id=item.id, seller_id=seller_id, price=100)
+            session.add(listing)
+            await session.commit()
+            await session.refresh(listing)
+
+            purchase = Purchase(
+                listing_id=listing.id,
+                buyer_id=buyer_id,
+                seller_id=seller_id,
+                price=100,
+                platform_fee=30,
+                seller_net=70,
+                status=PurchaseStatus.pending_escrow,
+            )
+            session.add(purchase)
+            await session.commit()
+            await session.refresh(purchase)
+
+            assert purchase.id is not None
+            assert purchase.seller_net == 70
+            assert purchase.status == PurchaseStatus.pending_escrow
+    finally:
+        await engine.dispose()

backend/tests/test_marketplace_purchases.py

@@ -0,0 +1,222 @@
+"""Integration tests for Marketplace Purchase Service, Escrow, and Fee Splitting.
+
+docs/planning/economy.md US-4 (task bc90d3f481b4).
+"""
+
+import pytest
+from fastapi.testclient import TestClient
+
+from app.main import app
+from app.services.purchase import purchase_service
+
+
+def _register(client: TestClient, username: str) -> tuple[int, dict[str, str]]:
+    resp = client.post(
+        "/api/auth/register",
+        json={
+            "username": username,
+            "email": f"{username}@example.com",
+            "password": "secret123",
+            "date_of_birth": "1990-01-01",
+        },
+    )
+    assert resp.status_code == 201, resp.text
+    token = resp.json()["access_token"]
+    headers = {"Authorization": f"Bearer {token}"}
+    me = client.get("/api/users/me", headers=headers)
+    assert me.status_code == 200, me.text
+    return me.json()["id"], headers
+
+
+def test_fee_split_calculation():
+    # 30% platform fee
+    fee, net = purchase_service.compute_fee_split(100)
+    assert fee == 30
+    assert net == 70
+
+    fee, net = purchase_service.compute_fee_split(250)
+    assert fee == 75
+    assert net == 175
+
+
+def test_marketplace_purchase_atomic_flow():
+    client = TestClient(app)
+    seller_id, seller_headers = _register(client, "purchase_seller_1")
+    buyer_id, buyer_headers = _register(client, "purchase_buyer_1")
+
+    # 1. Seller creates catalog item and lists it for 200 Credits
+    item_resp = client.post(
+        "/api/marketplace/items",
+        headers=seller_headers,
+        json={
+            "name": "Dragon Armor",
+            "description": "Legendary chestplate",
+            "item_type": "avatar_item",
+        },
+    )
+    assert item_resp.status_code == 201, item_resp.text
+    item_id = item_resp.json()["id"]
+
+    list_resp = client.post(
+        "/api/marketplace/listings",
+        headers=seller_headers,
+        json={
+            "catalog_item_id": item_id,
+            "price": 200,
+        },
+    )
+    assert list_resp.status_code == 201, list_resp.text
+    listing_id = list_resp.json()["id"]
+
+    # 2. Seller cannot purchase own listing
+    self_buy = client.post(
+        f"/api/marketplace/listings/{listing_id}/purchase",
+        headers=seller_headers,
+    )
+    assert self_buy.status_code == 400
+    assert "own listing" in self_buy.text
+
+    # 3. Buyer attempts purchase without enough credits -> 400
+    poor_buy = client.post(
+        f"/api/marketplace/listings/{listing_id}/purchase",
+        headers=buyer_headers,
+    )
+    assert poor_buy.status_code == 400
+    assert "Insufficient funds" in poor_buy.text
+
+    # 4. Buyer purchases 500 Credits via payments API
+    sess_resp = client.post(
+        "/api/payments/purchase",
+        headers=buyer_headers,
+        json={"credits": 500},
+    )
+    assert sess_resp.status_code == 201, sess_resp.text
+    sess_id = sess_resp.json()["session_id"]
+
+    conf_resp = client.post(
+        "/api/payments/confirm",
+        headers=buyer_headers,
+        json={"session_id": sess_id},
+    )
+    assert conf_resp.status_code == 200, conf_resp.text
+    assert conf_resp.json()["new_balance"] == 500
+
+    # 5. Buyer purchases listing for 200 Credits
+    buy_headers = dict(buyer_headers)
+    buy_headers["Idempotency-Key"] = "buy-test-key-1"
+    buy_resp = client.post(
+        f"/api/marketplace/listings/{listing_id}/purchase",
+        headers=buy_headers,
+    )
+    assert buy_resp.status_code == 201, buy_resp.text
+    purchase_data = buy_resp.json()
+    assert purchase_data["price"] == 200
+    assert purchase_data["platform_fee"] == 60
+    assert purchase_data["seller_net"] == 140
+    assert purchase_data["status"] == "pending_escrow"
+    assert purchase_data["buyer_id"] == buyer_id
+    assert purchase_data["seller_id"] == seller_id
+    purchase_id = purchase_data["id"]
+
+    # 6. Check buyer wallet balance: 500 - 200 = 300
+    w_resp = client.get("/api/wallet", headers=buyer_headers)
+    assert w_resp.status_code == 200
+    assert w_resp.json()["balance"] == 300
+
+    # 7. Check buyer has granted item in inventory
+    inv_resp = client.get("/api/marketplace/items", headers=buyer_headers, params={"mine": "true"})
+    assert inv_resp.status_code == 200
+    my_items = inv_resp.json()
+    assert any(i["name"] == "Dragon Armor" and i["owner_id"] == buyer_id for i in my_items)
+
+    # 8. Listing is now sold and cannot be purchased again
+    re_buy = client.post(
+        f"/api/marketplace/listings/{listing_id}/purchase",
+        headers=buyer_headers,
+    )
+    assert re_buy.status_code == 400
+    assert "not active" in re_buy.text
+
+    # 9. Seller's creator balance is pending escrow
+    cb_resp = client.get("/api/marketplace/creator/balance", headers=seller_headers)
+    assert cb_resp.status_code == 200, cb_resp.text
+    cb = cb_resp.json()
+    assert cb["pending"] == 140
+    assert cb["available"] == 0
+
+    # 10. List purchases
+    p_resp = client.get("/api/marketplace/purchases", headers=buyer_headers)
+    assert p_resp.status_code == 200
+    assert any(p["id"] == purchase_id for p in p_resp.json())
+
+    # 11. Escrow release
+    rel_resp = client.post(
+        f"/api/marketplace/purchases/{purchase_id}/release",
+        headers=seller_headers,
+    )
+    assert rel_resp.status_code == 200, rel_resp.text
+    assert rel_resp.json()["status"] == "completed"
+
+    # Check seller's creator balance now shows available = 140
+    cb_resp2 = client.get("/api/marketplace/creator/balance", headers=seller_headers)
+    assert cb_resp2.status_code == 200
+    cb2 = cb_resp2.json()
+    assert cb2["pending"] == 0
+    assert cb2["available"] == 140
+    assert cb2["lifetime_earned"] == 140
+
+
+def test_marketplace_refund():
+    client = TestClient(app)
+    seller_id, seller_headers = _register(client, "refund_seller_1")
+    buyer_id, buyer_headers = _register(client, "refund_buyer_1")
+
+    # Item & Listing
+    item_resp = client.post(
+        "/api/marketplace/items",
+        headers=seller_headers,
+        json={"name": "Magic Ring", "item_type": "avatar_item"},
+    )
+    item_id = item_resp.json()["id"]
+
+    list_resp = client.post(
+        "/api/marketplace/listings",
+        headers=seller_headers,
+        json={"catalog_item_id": item_id, "price": 100},
+    )
+    listing_id = list_resp.json()["id"]
+
+    # Fund buyer
+    s_resp = client.post("/api/payments/purchase", headers=buyer_headers, json={"credits": 500})
+    assert s_resp.status_code == 201, s_resp.text
+    client.post("/api/payments/confirm", headers=buyer_headers, json={"session_id": s_resp.json()["session_id"]})
+
+    # Purchase
+    buy_resp = client.post(f"/api/marketplace/listings/{listing_id}/purchase", headers=buyer_headers)
+    assert buy_resp.status_code == 201
+    purchase_id = buy_resp.json()["id"]
+
+    # Buyer balance is 400
+    w1 = client.get("/api/wallet", headers=buyer_headers).json()
+    assert w1["balance"] == 400
+
+    # Seller pending is 70
+    cb1 = client.get("/api/marketplace/creator/balance", headers=seller_headers).json()
+    assert cb1["pending"] == 70
+
+    # Refund
+    ref_resp = client.post(
+        f"/api/marketplace/purchases/{purchase_id}/refund",
+        headers=seller_headers,
+        json={"reason": "Buyer dissatisfaction"},
+    )
+    assert ref_resp.status_code == 200, ref_resp.text
+    assert ref_resp.json()["status"] == "refunded"
+
+    # Buyer balance refunded back to 500
+    w2 = client.get("/api/wallet", headers=buyer_headers).json()
+    assert w2["balance"] == 500
+
+    # Seller pending reset to 0
+    cb2 = client.get("/api/marketplace/creator/balance", headers=seller_headers).json()
+    assert cb2["pending"] == 0

backend/tests/test_payments.py

@@ -0,0 +1,123 @@
+"""Integration tests for Premium Purchase and PaymentProvider.
+
+docs/planning/economy.md US-2 (task 575fd14b5360).
+"""
+
+import pytest
+from fastapi.testclient import TestClient
+
+from app.main import app
+
+
+def _register(client: TestClient, username: str) -> tuple[int, dict[str, str]]:
+    resp = client.post(
+        "/api/auth/register",
+        json={
+            "username": username,
+            "email": f"{username}@example.com",
+            "password": "secret123",
+            "date_of_birth": "1990-01-01",
+        },
+    )
+    assert resp.status_code == 201, resp.text
+    token = resp.json()["access_token"]
+    headers = {"Authorization": f"Bearer {token}"}
+    me = client.get("/api/users/me", headers=headers)
+    assert me.status_code == 200, me.text
+    return me.json()["id"], headers
+
+
+def test_payments_unauthorized():
+    client = TestClient(app)
+    resp = client.post("/api/payments/purchase", json={"credits": 500})
+    assert resp.status_code == 401
+
+    resp = client.post("/api/payments/confirm", json={"session_id": "sess_123"})
+    assert resp.status_code == 401
+
+
+def test_purchase_rejects_arbitrary_amounts():
+    client = TestClient(app)
+    _, headers = _register(client, "pay_user_1")
+
+    # 42 credits is not an allowed pack
+    resp = client.post("/api/payments/purchase", json={"credits": 42}, headers=headers)
+    assert resp.status_code == 422
+
+    # Negative / 0 credits
+    resp = client.post("/api/payments/purchase", json={"credits": -100}, headers=headers)
+    assert resp.status_code == 422
+
+
+def test_purchase_and_confirm_flow():
+    client = TestClient(app)
+    uid, headers = _register(client, "pay_user_2")
+
+    # 1. Check initial balance
+    w_resp = client.get("/api/wallet", headers=headers)
+    assert w_resp.status_code == 200
+    assert w_resp.json()["balance"] == 0
+
+    # 2. Purchase session for 500 credits
+    p_resp = client.post(
+        "/api/payments/purchase",
+        json={"credits": 500},
+        headers={"Idempotency-Key": "sess_req_1", **headers},
+    )
+    assert p_resp.status_code == 201, p_resp.text
+    p_data = p_resp.json()
+    assert p_data["credits"] == 500
+    assert p_data["session_id"].startswith("sess_")
+    session_id = p_data["session_id"]
+
+    # Balance is still 0 before confirmation
+    w_resp = client.get("/api/wallet", headers=headers)
+    assert w_resp.json()["balance"] == 0
+
+    # 3. Confirm purchase session
+    c_resp = client.post(
+        "/api/payments/confirm",
+        json={"session_id": session_id},
+        headers=headers,
+    )
+    assert c_resp.status_code == 200, c_resp.text
+    c_data = c_resp.json()
+    assert c_data["confirmed"] is True
+    assert c_data["credits"] == 500
+    assert c_data["new_balance"] == 500
+    assert c_data["provider_ref"] != ""
+
+    # 4. Idempotent re-confirm must not double-credit
+    c_resp2 = client.post(
+        "/api/payments/confirm",
+        json={"session_id": session_id},
+        headers=headers,
+    )
+    assert c_resp2.status_code == 200
+    assert c_resp2.json()["new_balance"] == 500
+
+    # Check transactions in ledger: exactly 1 transaction
+    tx_resp = client.get("/api/wallet/transactions", headers=headers)
+    assert tx_resp.status_code == 200
+    tx_data = tx_resp.json()
+    assert tx_data["total"] == 1
+    assert tx_data["transactions"][0]["amount"] == 500
+    assert tx_data["transactions"][0]["type"] == "credit_purchase"
+
+
+def test_confirm_invalid_or_wrong_user_fails():
+    client = TestClient(app)
+    uid1, headers1 = _register(client, "pay_user_3a")
+    uid2, headers2 = _register(client, "pay_user_3b")
+
+    # User 1 creates a session
+    p_resp = client.post("/api/payments/purchase", json={"credits": 100}, headers=headers1)
+    session_id = p_resp.json()["session_id"]
+
+    # User 2 tries to confirm User 1's session -> must fail 400
+    bad_resp = client.post("/api/payments/confirm", json={"session_id": session_id}, headers=headers2)
+    assert bad_resp.status_code == 400
+
+    # Non-existent session -> must fail 400
+    bad_resp2 = client.post("/api/payments/confirm", json={"session_id": "sess_nonexistent"}, headers=headers1)
+    assert bad_resp2.status_code == 400

backend/tests/test_presence.py

@@ -0,0 +1,221 @@
+"""Integration tests for the presence feature:
+
+- POST  /api/presence/heartbeat
+- GET   /api/presence/presence
+- PATCH /api/presence/status
+
+Hits the real app against the configured Postgres *and* a real Redis
+(conftest.py brings up an ephemeral instance of each when neither is
+already reachable) -- presence is fundamentally "does a TTL key exist in
+Redis", which isn't worth faking with a mock.
+
+Also covers the regression fixed in 47ab492 ("Fix StatusUpdate field
+annotation and is_online batch-call mismatch"): the router used to call
+``PresenceStore.is_online(ids)`` with a *list* of ids and then evaluate
+``uid in online_ids`` against the returned bool, which raised a TypeError
+on the first real multi-id batch call, and ``StatusUpdate.status_message``
+used the invalid annotation ``str | Field(...)``. Both are exercised below.
+"""
+
+import asyncio
+
+import pytest
+from fastapi.testclient import TestClient
+
+from app.main import app
+from app.services.presence import PresenceStore
+
+
+def _register(client: TestClient, username: str) -> dict:
+    resp = client.post(
+        "/api/auth/register",
+        json={
+            "username": username,
+            "email": f"{username}@example.com",
+            "password": "secret123",
+            "date_of_birth": "1990-01-01",
+        },
+    )
+    assert resp.status_code == 201, resp.text
+    token = resp.json()["access_token"]
+    headers = {"Authorization": f"Bearer {token}"}
+    me = client.get("/api/users/me", headers=headers)
+    assert me.status_code == 200, me.text
+    return {"headers": headers, "id": me.json()["id"]}
+
+
+class TestHeartbeat:
+    def test_heartbeat_sets_online(self):
+        client = TestClient(app)
+        user = _register(client, "presence_hb1")
+
+        resp = client.post("/api/presence/heartbeat", json={}, headers=user["headers"])
+        assert resp.status_code == 200, resp.text
+        assert resp.json() == {"status": "ok", "user_id": user["id"]}
+
+        presence = client.get(
+            "/api/presence/presence",
+            params={"user_ids": str(user["id"])},
+            headers=user["headers"],
+        )
+        assert presence.status_code == 200, presence.text
+        body = presence.json()["users"]
+        assert len(body) == 1
+        assert body[0]["user_id"] == user["id"]
+        assert body[0]["is_online"] is True
+        assert body[0]["last_seen_at"] is not None
+
+    def test_requires_auth(self):
+        client = TestClient(app)
+        resp = client.post("/api/presence/heartbeat", json={})
+        assert resp.status_code == 401
+
+    def test_never_seen_user_is_offline_with_null_last_seen(self):
+        client = TestClient(app)
+        user = _register(client, "presence_never_hb")
+
+        presence = client.get(
+            "/api/presence/presence",
+            params={"user_ids": str(user["id"])},
+            headers=user["headers"],
+        )
+        assert presence.status_code == 200
+        body = presence.json()["users"][0]
+        assert body["is_online"] is False
+        assert body["last_seen_at"] is None
+
+
+class TestBatchPresence:
+    """Covers the batch-call path fixed in 47ab492 (is_online_batch via MGET)."""
+
+    def test_batch_query_mixes_online_offline_and_unknown_ids(self):
+        client = TestClient(app)
+        online_user = _register(client, "presence_batch_online")
+        offline_user = _register(client, "presence_batch_offline")
+
+        client.post("/api/presence/heartbeat", json={}, headers=online_user["headers"])
+
+        unknown_id = max(online_user["id"], offline_user["id"]) + 999_999
+        ids = f"{online_user['id']},{offline_user['id']},{unknown_id}"
+
+        resp = client.get(
+            "/api/presence/presence",
+            params={"user_ids": ids},
+            headers=online_user["headers"],
+        )
+        assert resp.status_code == 200, resp.text
+        by_id = {u["user_id"]: u for u in resp.json()["users"]}
+
+        # Unknown id is silently dropped (not in the DB), not a 500 or 404.
+        assert unknown_id not in by_id
+        assert by_id[online_user["id"]]["is_online"] is True
+        assert by_id[offline_user["id"]]["is_online"] is False
+
+    def test_empty_user_ids_is_a_400(self):
+        client = TestClient(app)
+        user = _register(client, "presence_empty_ids")
+        resp = client.get(
+            "/api/presence/presence",
+            params={"user_ids": ""},
+            headers=user["headers"],
+        )
+        assert resp.status_code == 400
+
+
+class TestStatusMessage:
+    def test_update_and_read_back_status_message(self):
+        client = TestClient(app)
+        user = _register(client, "presence_status1")
+
+        resp = client.patch(
+            "/api/presence/status",
+            json={"status_message": "  brb, making coffee  "},
+            headers=user["headers"],
+        )
+        assert resp.status_code == 200, resp.text
+        # The router strips whitespace (StatusUpdate.strip_message).
+        assert resp.json()["status_message"] == "brb, making coffee"
+
+        presence = client.get(
+            "/api/presence/presence",
+            params={"user_ids": str(user["id"])},
+            headers=user["headers"],
+        )
+        assert presence.json()["users"][0]["status_message"] == "brb, making coffee"
+
+    def test_status_message_over_max_length_is_rejected(self):
+        client = TestClient(app)
+        user = _register(client, "presence_status_toolong")
+        resp = client.patch(
+            "/api/presence/status",
+            json={"status_message": "x" * 141},
+            headers=user["headers"],
+        )
+        # StatusUpdate.status_message: str | None = Field(..., max_length=140)
+        # This is exactly the annotation 47ab492 fixed (it used to be the
+        # invalid `str | Field(...)`, which breaks model construction
+        # entirely rather than validating length).
+        assert resp.status_code == 422
+
+    def test_status_message_at_max_length_is_accepted(self):
+        client = TestClient(app)
+        user = _register(client, "presence_status_maxlen")
+        resp = client.patch(
+            "/api/presence/status",
+            json={"status_message": "x" * 140},
+            headers=user["headers"],
+        )
+        assert resp.status_code == 200, resp.text
+
+    def test_null_status_message_clears_it(self):
+        client = TestClient(app)
+        user = _register(client, "presence_status_clear")
+        client.patch("/api/presence/status", json={"status_message": "hi"}, headers=user["headers"])
+        resp = client.patch("/api/presence/status", json={"status_message": None}, headers=user["headers"])
+        assert resp.status_code == 200
+        assert resp.json()["status_message"] is None
+
+
+class TestPresenceStoreTTL:
+    """Exercises the real Redis TTL semantics directly against the service,
+    with a short heartbeat_ttl so the test doesn't need to sleep for the
+    real 60s default used in production. This is the cheap, real proxy for
+    "TTL expiry means offline" the task asked for -- same code path
+    (real Redis SET ... EX / EXISTS / MGET), just a much shorter window.
+    """
+
+    async def test_ttl_expiry_flips_online_to_offline(self):
+        store = PresenceStore(heartbeat_ttl=1)
+        try:
+            uid = 987654321  # doesn't need to exist in Postgres; Redis-only check
+            assert await store.is_online(uid) is False
+
+            await store.heartbeat(uid)
+            assert await store.is_online(uid) is True
+
+            await asyncio.sleep(1.5)
+            assert await store.is_online(uid) is False
+        finally:
+            await store.close()
+
+    async def test_is_online_batch_matches_is_online_semantics(self):
+        """Regression coverage for 47ab492: is_online_batch must return a
+        set of ids usable with `in`, not a bool."""
+        store = PresenceStore(heartbeat_ttl=30)
+        try:
+            online_uid, offline_uid = 111222333, 444555666
+            await store.heartbeat(online_uid)
+
+            result = await store.is_online_batch([online_uid, offline_uid])
+            assert isinstance(result, set)
+            assert online_uid in result
+            assert offline_uid not in result
+        finally:
+            await store.close()
+
+    async def test_is_online_batch_empty_list(self):
+        store = PresenceStore()
+        try:
+            assert await store.is_online_batch([]) == set()
+        finally:
+            await store.close()

backend/tests/test_profile.py

@@ -0,0 +1,406 @@
+"""Integration tests for /api/profile/me and /api/profile/me/favorites.
+
+Hits the real app against the configured Postgres (same contract as the
+other integration tests -- migrations applied first).
+"""
+
+import asyncio
+
+import pytest
+from fastapi.testclient import TestClient
+from sqlalchemy import text
+from sqlalchemy.ext.asyncio import create_async_engine
+from sqlalchemy.pool import NullPool
+
+from app.config import settings
+from app.main import app
+from app.models.profile import DEFAULT_PRIVACY
+
+
+def _auth_headers(client: TestClient, username: str) -> dict:
+    resp = client.post(
+        "/api/auth/register",
+        json={
+            "username": username,
+            "email": f"{username}@example.com",
+            "password": "secret123",
+            "date_of_birth": "1990-01-01",
+        },
+    )
+    assert resp.status_code == 201, resp.text
+    return {"Authorization": f"Bearer {resp.json()['access_token']}"}
+
+
+def _me_id(client: TestClient, headers: dict) -> int:
+    me = client.get("/api/users/me", headers=headers)
+    assert me.status_code == 200, me.text
+    return me.json()["id"]
+
+
+def _make_world(client: TestClient, headers: dict, name: str = "W") -> int:
+    r = client.post("/api/worlds/", headers=headers, json={"name": name, "visibility": "public"})
+    assert r.status_code == 201, r.text
+    return r.json()["id"]
+
+
+def _make_asset(client: TestClient, headers: dict, name: str = "A") -> int:
+    """Insert an asset row directly via raw SQL.
+
+    Not going through POST /api/assets/, and not through the Asset ORM
+    model, deliberately: Asset.asset_type's ENUM column has no
+    values_callable, so SQLAlchemy sends the Python enum *name* (e.g.
+    "IMAGE") to Postgres instead of the lowercase value the DB enum
+    actually stores ("image"), and both the router and a plain ORM insert
+    500/fail on it. That's a pre-existing bug unrelated to this task; these
+    tests only need a real asset row to reference by id, so insert with raw
+    SQL to sidestep the buggy enum type entirely.
+    """
+    owner_id = _me_id(client, headers)
+
+    async def _create() -> int:
+        engine = create_async_engine(settings.DATABASE_URL, poolclass=NullPool)
+        async with engine.begin() as conn:
+            result = await conn.execute(
+                text(
+                    "INSERT INTO assets (name, asset_type, file_path, owner_id, is_public) "
+                    "VALUES (:name, 'image', '', :owner_id, false) RETURNING id"
+                ),
+                {"name": name, "owner_id": owner_id},
+            )
+            asset_id = result.scalar_one()
+        await engine.dispose()
+        return asset_id
+
+    return asyncio.run(_create())
+
+
+class TestGetProfile:
+    def test_new_user_gets_the_default(self):
+        client = TestClient(app)
+        headers = _auth_headers(client, "pf_default")
+        resp = client.get("/api/profile/me", headers=headers)
+        assert resp.status_code == 200
+        body = resp.json()
+        assert body["is_default"] is True
+        assert body["bio"] is None
+        assert body["avatar_asset_id"] is None
+        assert body["privacy"] == DEFAULT_PRIVACY
+
+    def test_requires_auth(self):
+        client = TestClient(app)
+        assert client.get("/api/profile/me").status_code == 401
+
+
+class TestPutProfile:
+    def test_save_then_read_back(self):
+        client = TestClient(app)
+        headers = _auth_headers(client, "pf_save")
+        asset_id = _make_asset(client, headers)
+
+        put = client.put(
+            "/api/profile/me", headers=headers,
+            json={"bio": "hello world", "avatar_asset_id": asset_id,
+                  "privacy": {"profile_visibility": "friends"}},
+        )
+        assert put.status_code == 200, put.text
+        body = put.json()
+        assert body["is_default"] is False
+        assert body["bio"] == "hello world"
+        assert body["avatar_asset_id"] == asset_id
+        assert body["privacy"]["profile_visibility"] == "friends"
+        # unspecified privacy keys keep their default
+        assert body["privacy"]["friends_list_visibility"] == "public"
+
+        got = client.get("/api/profile/me", headers=headers)
+        assert got.status_code == 200
+        assert got.json() == body
+
+    def test_partial_update_preserves_other_fields(self):
+        client = TestClient(app)
+        headers = _auth_headers(client, "pf_partial")
+        client.put("/api/profile/me", headers=headers, json={"bio": "first bio"})
+        put2 = client.put("/api/profile/me", headers=headers, json={"privacy": {"favorites_visibility": "private"}})
+        assert put2.status_code == 200, put2.text
+        body = put2.json()
+        assert body["bio"] == "first bio"
+        assert body["privacy"]["favorites_visibility"] == "private"
+
+    def test_other_user_cannot_edit_my_profile(self):
+        """There is no user_id-scoped edit route at all -- PUT /me always
+        acts on the caller's own JWT identity, so another user's token can
+        never touch this user's profile."""
+        client = TestClient(app)
+        headers_a = _auth_headers(client, "pf_owner")
+        headers_b = _auth_headers(client, "pf_other")
+
+        client.put("/api/profile/me", headers=headers_a, json={"bio": "owner's bio"})
+        client.put("/api/profile/me", headers=headers_b, json={"bio": "other's bio"})
+
+        got_a = client.get("/api/profile/me", headers=headers_a).json()
+        got_b = client.get("/api/profile/me", headers=headers_b).json()
+        assert got_a["bio"] == "owner's bio"
+        assert got_b["bio"] == "other's bio"
+        assert got_a["user_id"] != got_b["user_id"]
+
+    def test_rejects_invalid_avatar_asset_id(self):
+        client = TestClient(app)
+        headers = _auth_headers(client, "pf_badasset")
+        resp = client.put("/api/profile/me", headers=headers, json={"avatar_asset_id": 999999})
+        assert resp.status_code == 422
+
+    def test_rejects_over_length_bio(self):
+        client = TestClient(app)
+        headers = _auth_headers(client, "pf_longbio")
+        resp = client.put("/api/profile/me", headers=headers, json={"bio": "x" * 501})
+        assert resp.status_code == 422
+
+    def test_accepts_bio_at_max_length(self):
+        client = TestClient(app)
+        headers = _auth_headers(client, "pf_maxbio")
+        resp = client.put("/api/profile/me", headers=headers, json={"bio": "x" * 500})
+        assert resp.status_code == 200, resp.text
+
+    def test_rejects_unknown_privacy_key(self):
+        client = TestClient(app)
+        headers = _auth_headers(client, "pf_badprivkey")
+        resp = client.put("/api/profile/me", headers=headers, json={"privacy": {"nonsense_key": "public"}})
+        assert resp.status_code == 422
+
+    def test_rejects_invalid_privacy_value(self):
+        client = TestClient(app)
+        headers = _auth_headers(client, "pf_badprivval")
+        resp = client.put("/api/profile/me", headers=headers, json={"privacy": {"profile_visibility": "nope"}})
+        assert resp.status_code == 422
+
+    def test_requires_auth(self):
+        client = TestClient(app)
+        resp = client.put("/api/profile/me", json={"bio": "x"})
+        assert resp.status_code == 401
+
+
+class TestFavorites:
+    def test_new_user_has_no_favorites(self):
+        client = TestClient(app)
+        headers = _auth_headers(client, "fav_default")
+        resp = client.get("/api/profile/me/favorites", headers=headers)
+        assert resp.status_code == 200
+        assert resp.json() == {"world_ids": []}
+
+    def test_replace_then_read_back(self):
+        client = TestClient(app)
+        headers = _auth_headers(client, "fav_save")
+        w1 = _make_world(client, headers, "W1")
+        w2 = _make_world(client, headers, "W2")
+
+        put = client.put("/api/profile/me/favorites", headers=headers, json={"world_ids": [w1, w2]})
+        assert put.status_code == 200, put.text
+        assert set(put.json()["world_ids"]) == {w1, w2}
+
+        got = client.get("/api/profile/me/favorites", headers=headers)
+        assert set(got.json()["world_ids"]) == {w1, w2}
+
+    def test_replace_is_a_full_replace_not_append(self):
+        client = TestClient(app)
+        headers = _auth_headers(client, "fav_replace")
+        w1 = _make_world(client, headers, "W1")
+        w2 = _make_world(client, headers, "W2")
+
+        client.put("/api/profile/me/favorites", headers=headers, json={"world_ids": [w1]})
+        second = client.put("/api/profile/me/favorites", headers=headers, json={"world_ids": [w2]})
+        assert second.json()["world_ids"] == [w2]
+
+        got = client.get("/api/profile/me/favorites", headers=headers)
+        assert got.json()["world_ids"] == [w2]
+
+    def test_replace_with_empty_list_clears_favorites(self):
+        client = TestClient(app)
+        headers = _auth_headers(client, "fav_clear")
+        w1 = _make_world(client, headers, "W1")
+        client.put("/api/profile/me/favorites", headers=headers, json={"world_ids": [w1]})
+        cleared = client.put("/api/profile/me/favorites", headers=headers, json={"world_ids": []})
+        assert cleared.status_code == 200
+        assert cleared.json() == {"world_ids": []}
+
+    def test_rejects_nonexistent_world_id(self):
+        client = TestClient(app)
+        headers = _auth_headers(client, "fav_badworld")
+        resp = client.put("/api/profile/me/favorites", headers=headers, json={"world_ids": [999999]})
+        assert resp.status_code == 422
+
+    def test_rejects_nonexistent_world_id_mixed_with_valid(self):
+        client = TestClient(app)
+        headers = _auth_headers(client, "fav_mixed")
+        w1 = _make_world(client, headers, "W1")
+        resp = client.put("/api/profile/me/favorites", headers=headers, json={"world_ids": [w1, 999999]})
+        assert resp.status_code == 422
+        # nothing partially applied
+        got = client.get("/api/profile/me/favorites", headers=headers)
+        assert got.json()["world_ids"] == []
+
+    def test_favorites_isolated_per_user(self):
+        client = TestClient(app)
+        headers_a = _auth_headers(client, "fav_owner")
+        headers_b = _auth_headers(client, "fav_other")
+        w1 = _make_world(client, headers_a, "W1")
+
+        client.put("/api/profile/me/favorites", headers=headers_a, json={"world_ids": [w1]})
+        got_b = client.get("/api/profile/me/favorites", headers=headers_b)
+        assert got_b.json()["world_ids"] == []
+
+    def test_requires_auth(self):
+        client = TestClient(app)
+        assert client.get("/api/profile/me/favorites").status_code == 401
+        assert client.put("/api/profile/me/favorites", json={"world_ids": []}).status_code == 401
+
+
+class TestPublicProfile:
+    def test_public_profile_full_view(self):
+        client = TestClient(app)
+        h_alice = _auth_headers(client, "pub_alice")
+        alice_id = _me_id(client, h_alice)
+        h_bob = _auth_headers(client, "pub_bob")
+
+        w1 = _make_world(client, h_alice, "AliceWorld")
+        asset_id = _make_asset(client, h_alice, "AliceAsset")
+
+        client.put(
+            "/api/profile/me",
+            headers=h_alice,
+            json={"bio": "Hi, I am Alice", "avatar_asset_id": asset_id},
+        )
+        client.put("/api/profile/me/favorites", headers=h_alice, json={"world_ids": [w1]})
+
+        resp = client.get(f"/api/profile/{alice_id}", headers=h_bob)
+        assert resp.status_code == 200, resp.text
+        data = resp.json()
+        assert data["user_id"] == alice_id
+        assert data["username"] == "pub_alice"
+        assert data["bio"] == "Hi, I am Alice"
+        assert data["avatar_asset_id"] == asset_id
+        assert data["is_restricted"] is False
+        assert len(data["favorites"]) == 1
+        assert data["favorites"][0]["id"] == w1
+        assert data["favorites"][0]["name"] == "AliceWorld"
+        assert "email" not in data
+        assert "password" not in data
+
+    def test_public_profile_not_found(self):
+        client = TestClient(app)
+        h_bob = _auth_headers(client, "pub_nf_bob")
+        resp = client.get("/api/profile/999999", headers=h_bob)
+        assert resp.status_code == 404
+
+    def test_public_profile_requires_auth(self):
+        client = TestClient(app)
+        assert client.get("/api/profile/1").status_code == 401
+
+    def test_public_profile_private_visibility(self):
+        client = TestClient(app)
+        h_alice = _auth_headers(client, "pub_priv_a")
+        alice_id = _me_id(client, h_alice)
+        h_bob = _auth_headers(client, "pub_priv_b")
+
+        client.put(
+            "/api/profile/me",
+            headers=h_alice,
+            json={"bio": "Top secret bio", "privacy": {"profile_visibility": "private"}},
+        )
+
+        resp_bob = client.get(f"/api/profile/{alice_id}", headers=h_bob)
+        assert resp_bob.status_code == 200
+        data_bob = resp_bob.json()
+        assert data_bob["is_restricted"] is True
+        assert data_bob["bio"] is None
+        assert data_bob["favorites"] == []
+        assert data_bob["friends"] == []
+
+        # Alice viewing herself is not restricted
+        resp_alice = client.get(f"/api/profile/{alice_id}", headers=h_alice)
+        assert resp_alice.status_code == 200
+        assert resp_alice.json()["is_restricted"] is False
+        assert resp_alice.json()["bio"] == "Top secret bio"
+
+    def test_public_profile_friends_only_visibility(self):
+        client = TestClient(app)
+        h_alice = _auth_headers(client, "pub_fo_a")
+        alice_id = _me_id(client, h_alice)
+        h_bob = _auth_headers(client, "pub_fo_b")
+        bob_id = _me_id(client, h_bob)
+        h_charlie = _auth_headers(client, "pub_fo_c")
+
+        client.put(
+            "/api/profile/me",
+            headers=h_alice,
+            json={"bio": "Friends only bio", "privacy": {"profile_visibility": "friends"}},
+        )
+
+        # Charlie is not a friend -> restricted
+        resp_c = client.get(f"/api/profile/{alice_id}", headers=h_charlie)
+        assert resp_c.json()["is_restricted"] is True
+        assert resp_c.json()["bio"] is None
+
+        # Bob becomes friends with Alice
+        req = client.post("/api/friends/requests", headers=h_bob, json={"user_id": alice_id})
+        req_id = req.json()["id"]
+        client.post(f"/api/friends/requests/{req_id}/accept", headers=h_alice)
+
+        # Now Bob sees full profile and friends list contains Bob
+        resp_b = client.get(f"/api/profile/{alice_id}", headers=h_bob)
+        assert resp_b.json()["is_restricted"] is False
+        assert resp_b.json()["bio"] == "Friends only bio"
+        assert any(f["id"] == bob_id for f in resp_b.json()["friends"])
+
+    def test_public_profile_blocked_user_gets_restricted(self):
+        client = TestClient(app)
+        h_alice = _auth_headers(client, "pub_blk_a")
+        alice_id = _me_id(client, h_alice)
+        h_dan = _auth_headers(client, "pub_blk_d")
+        dan_id = _me_id(client, h_dan)
+
+        client.put("/api/profile/me", headers=h_alice, json={"bio": "Alice public bio"})
+        client.post(f"/api/friends/{dan_id}/block", headers=h_alice)
+
+        # Dan viewing Alice gets restricted view
+        resp_dan = client.get(f"/api/profile/{alice_id}", headers=h_dan)
+        assert resp_dan.status_code == 200
+        assert resp_dan.json()["is_restricted"] is True
+        assert resp_dan.json()["bio"] is None
+
+        # Alice viewing Dan gets restricted view
+        resp_alice = client.get(f"/api/profile/{dan_id}", headers=h_alice)
+        assert resp_alice.status_code == 200
+        assert resp_alice.json()["is_restricted"] is True
+
+    def test_public_profile_selective_favorites_and_friends_privacy(self):
+        client = TestClient(app)
+        h_alice = _auth_headers(client, "pub_sec_a")
+        alice_id = _me_id(client, h_alice)
+        h_bob = _auth_headers(client, "pub_sec_b")
+        bob_id = _me_id(client, h_bob)
+        w1 = _make_world(client, h_alice, "WorldSec")
+
+        client.put("/api/profile/me/favorites", headers=h_alice, json={"world_ids": [w1]})
+        req = client.post("/api/friends/requests", headers=h_bob, json={"user_id": alice_id})
+        req_id = req.json()["id"]
+        client.post(f"/api/friends/requests/{req_id}/accept", headers=h_alice)
+
+        client.put(
+            "/api/profile/me",
+            headers=h_alice,
+            json={
+                "bio": "Bio is public",
+                "privacy": {
+                    "profile_visibility": "public",
+                    "favorites_visibility": "private",
+                    "friends_list_visibility": "private",
+                },
+            },
+        )
+
+        resp = client.get(f"/api/profile/{alice_id}", headers=h_bob)
+        assert resp.status_code == 200
+        data = resp.json()
+        assert data["bio"] == "Bio is public"
+        assert data["favorites"] == []
+        assert data["friends"] == []
+

backend/tests/test_rate_limit.py

@@ -1,6 +1,7 @@
 """The auth endpoints are rate-limited per client IP."""
 
 import pytest
+from fastapi import Depends, FastAPI
 from fastapi.testclient import TestClient
 
 from app import rate_limit
@@ -54,3 +55,70 @@ def test_limiter_window_is_per_key():
     with pytest.raises(Exception):
         limiter.check("a")
     limiter.check("b")  # different key, unaffected
+
+
+def _make_named_limit_app():
+    """A tiny standalone app exercising two independent named limits, so
+    these tests don't depend on any sibling endpoint existing yet."""
+    limit_a = rate_limit.rate_limit("test_named_a", max_hits=2, window_seconds=60)
+    limit_b = rate_limit.rate_limit("test_named_b", max_hits=2, window_seconds=60)
+
+    app = FastAPI()
+
+    @app.post("/a", dependencies=[Depends(limit_a)])
+    def _a():
+        return {"ok": True}
+
+    @app.post("/b", dependencies=[Depends(limit_b)])
+    def _b():
+        return {"ok": True}
+
+    return TestClient(app)
+
+
+def test_named_limits_do_not_share_counters():
+    client = _make_named_limit_app()
+
+    # Burn out limit "a" entirely.
+    assert client.post("/a").status_code == 200
+    assert client.post("/a").status_code == 200
+    r = client.post("/a")
+    assert r.status_code == 429
+    assert "Retry-After" in r.headers
+
+    # Limit "b" is untouched -- same process, same client IP, different name.
+    assert client.post("/b").status_code == 200
+    assert client.post("/b").status_code == 200
+    assert client.post("/b").status_code == 429
+
+
+def test_named_limit_returns_429_with_retry_after_once_exhausted():
+    client = _make_named_limit_app()
+    client.post("/a")
+    client.post("/a")
+    r = client.post("/a")
+    assert r.status_code == 429
+    retry_after = r.headers["Retry-After"]
+    assert int(retry_after) >= 1
+
+
+def test_named_limit_is_a_noop_when_rate_limiting_disabled():
+    prev = settings.RATE_LIMIT_ENABLED
+    settings.RATE_LIMIT_ENABLED = False
+    try:
+        client = _make_named_limit_app()
+        codes = [client.post("/a").status_code for _ in range(10)]
+        assert codes == [200] * 10
+    finally:
+        settings.RATE_LIMIT_ENABLED = prev
+
+
+def test_reset_all_clears_named_limiters_too():
+    client = _make_named_limit_app()
+    client.post("/a")
+    client.post("/a")
+    assert client.post("/a").status_code == 429
+
+    rate_limit.reset_all()
+
+    assert client.post("/a").status_code == 200

backend/tests/test_social_friends.py

@@ -0,0 +1,317 @@
+"""Integration tests for the friends/follow/block API:
+
+- POST   /api/friends/requests
+- GET    /api/friends/requests
+- POST   /api/friends/requests/{id}/accept
+- POST   /api/friends/requests/{id}/decline
+- DELETE /api/friends/{user_id}
+- POST   /api/friends/{user_id}/follow
+- DELETE /api/friends/{user_id}/follow
+- POST   /api/friends/{user_id}/block
+- DELETE /api/friends/{user_id}/block
+- GET    /api/friends
+- GET    /api/friends/following
+- GET    /api/friends/blocked
+
+app/routers/social_friends.py, built on the merged models in
+app/models/social.py (Friendship/Follow/Block).
+"""
+
+from fastapi.testclient import TestClient
+
+from app.main import app
+
+
+def _register(client: TestClient, username: str) -> dict:
+    resp = client.post(
+        "/api/auth/register",
+        json={
+            "username": username,
+            "email": f"{username}@example.com",
+            "password": "secret123",
+            "date_of_birth": "1990-01-01",
+        },
+    )
+    assert resp.status_code == 201, resp.text
+    token = resp.json()["access_token"]
+    headers = {"Authorization": f"Bearer {token}"}
+    me = client.get("/api/users/me", headers=headers)
+    assert me.status_code == 200, me.text
+    return {"headers": headers, "id": me.json()["id"]}
+
+
+class TestFriendRequestFlow:
+    def test_send_list_accept_makes_mutual_friendship(self):
+        client = TestClient(app)
+        a = _register(client, "fr_flow_a")
+        b = _register(client, "fr_flow_b")
+
+        resp = client.post("/api/friends/requests", json={"user_id": b["id"]}, headers=a["headers"])
+        assert resp.status_code == 201, resp.text
+        request_id = resp.json()["id"]
+        assert resp.json()["status"] == "pending"
+
+        incoming = client.get("/api/friends/requests", headers=b["headers"])
+        assert incoming.status_code == 200
+        ids = [r["id"] for r in incoming.json()["requests"]]
+        assert request_id in ids
+
+        # Requester doesn't see it in their own incoming list.
+        a_incoming = client.get("/api/friends/requests", headers=a["headers"])
+        assert a_incoming.json()["requests"] == []
+
+        accept = client.post(f"/api/friends/requests/{request_id}/accept", headers=b["headers"])
+        assert accept.status_code == 200, accept.text
+        assert accept.json()["status"] == "accepted"
+
+        # Mutual: shows up in both users' friend lists.
+        a_friends = client.get("/api/friends", headers=a["headers"]).json()["friends"]
+        b_friends = client.get("/api/friends", headers=b["headers"]).json()["friends"]
+        assert any(u["id"] == b["id"] for u in a_friends)
+        assert any(u["id"] == a["id"] for u in b_friends)
+
+    def test_decline_removes_request_and_allows_re_request(self):
+        client = TestClient(app)
+        a = _register(client, "fr_decl_a")
+        b = _register(client, "fr_decl_b")
+
+        resp = client.post("/api/friends/requests", json={"user_id": b["id"]}, headers=a["headers"])
+        request_id = resp.json()["id"]
+
+        decline = client.post(f"/api/friends/requests/{request_id}/decline", headers=b["headers"])
+        assert decline.status_code == 200, decline.text
+
+        assert client.get("/api/friends/requests", headers=b["headers"]).json()["requests"] == []
+
+        # A can send a new request now that the old one is gone.
+        resp2 = client.post("/api/friends/requests", json={"user_id": b["id"]}, headers=a["headers"])
+        assert resp2.status_code == 201, resp2.text
+
+    def test_accept_or_decline_of_others_request_is_404_not_403(self):
+        client = TestClient(app)
+        a = _register(client, "fr_enum_a")
+        b = _register(client, "fr_enum_b")
+        c = _register(client, "fr_enum_c")
+
+        resp = client.post("/api/friends/requests", json={"user_id": b["id"]}, headers=a["headers"])
+        request_id = resp.json()["id"]
+
+        # c is neither requester nor addressee -- must not be able to act on it,
+        # and must not be able to distinguish "not yours" from "doesn't exist".
+        accept = client.post(f"/api/friends/requests/{request_id}/accept", headers=c["headers"])
+        assert accept.status_code == 404
+
+        decline = client.post(f"/api/friends/requests/{request_id}/decline", headers=c["headers"])
+        assert decline.status_code == 404
+
+        nonexistent = client.post("/api/friends/requests/999999999/accept", headers=c["headers"])
+        assert nonexistent.status_code == 404
+
+    def test_unfriend_removes_mutual_friendship(self):
+        client = TestClient(app)
+        a = _register(client, "fr_unfr_a")
+        b = _register(client, "fr_unfr_b")
+
+        request_id = client.post(
+            "/api/friends/requests", json={"user_id": b["id"]}, headers=a["headers"]
+        ).json()["id"]
+        client.post(f"/api/friends/requests/{request_id}/accept", headers=b["headers"])
+
+        unfriend = client.delete(f"/api/friends/{a['id']}", headers=b["headers"])
+        assert unfriend.status_code == 200, unfriend.text
+
+        assert client.get("/api/friends", headers=a["headers"]).json()["friends"] == []
+        assert client.get("/api/friends", headers=b["headers"]).json()["friends"] == []
+
+        # Idempotency / no dangling state: unfriending again is a clean 404, not 500.
+        again = client.delete(f"/api/friends/{a['id']}", headers=b["headers"])
+        assert again.status_code == 404
+
+
+class TestSelfAndDuplicateRejection:
+    def test_self_request_rejected(self):
+        client = TestClient(app)
+        a = _register(client, "self_req_a")
+        resp = client.post("/api/friends/requests", json={"user_id": a["id"]}, headers=a["headers"])
+        assert resp.status_code == 400
+
+    def test_self_follow_rejected(self):
+        client = TestClient(app)
+        a = _register(client, "self_follow_a")
+        resp = client.post(f"/api/friends/{a['id']}/follow", headers=a["headers"])
+        assert resp.status_code == 400
+
+    def test_self_block_rejected(self):
+        client = TestClient(app)
+        a = _register(client, "self_block_a")
+        resp = client.post(f"/api/friends/{a['id']}/block", headers=a["headers"])
+        assert resp.status_code == 400
+
+    def test_duplicate_friend_request_is_conflict_not_500(self):
+        client = TestClient(app)
+        a = _register(client, "dup_req_a")
+        b = _register(client, "dup_req_b")
+        assert client.post("/api/friends/requests", json={"user_id": b["id"]}, headers=a["headers"]).status_code == 201
+        dup = client.post("/api/friends/requests", json={"user_id": b["id"]}, headers=a["headers"])
+        assert dup.status_code == 409
+
+    def test_reverse_duplicate_friend_request_is_conflict(self):
+        """b requesting a while a's request to b is still pending is treated
+        as a duplicate of the same pair, not a second independent request."""
+        client = TestClient(app)
+        a = _register(client, "dup_rev_a")
+        b = _register(client, "dup_rev_b")
+        assert client.post("/api/friends/requests", json={"user_id": b["id"]}, headers=a["headers"]).status_code == 201
+        reverse = client.post("/api/friends/requests", json={"user_id": a["id"]}, headers=b["headers"])
+        assert reverse.status_code == 409
+
+    def test_duplicate_follow_is_conflict_not_500(self):
+        client = TestClient(app)
+        a = _register(client, "dup_follow_a")
+        b = _register(client, "dup_follow_b")
+        assert client.post(f"/api/friends/{b['id']}/follow", headers=a["headers"]).status_code == 201
+        dup = client.post(f"/api/friends/{b['id']}/follow", headers=a["headers"])
+        assert dup.status_code == 409
+
+    def test_duplicate_block_is_conflict_not_500(self):
+        client = TestClient(app)
+        a = _register(client, "dup_block_a")
+        b = _register(client, "dup_block_b")
+        assert client.post(f"/api/friends/{b['id']}/block", headers=a["headers"]).status_code == 201
+        dup = client.post(f"/api/friends/{b['id']}/block", headers=a["headers"])
+        assert dup.status_code == 409
+
+    def test_friend_request_to_nonexistent_user_is_404(self):
+        client = TestClient(app)
+        a = _register(client, "req_missing_a")
+        resp = client.post("/api/friends/requests", json={"user_id": 999999999}, headers=a["headers"])
+        assert resp.status_code == 404
+
+
+class TestFollow:
+    def test_follow_unfollow_and_list(self):
+        client = TestClient(app)
+        a = _register(client, "follow_flow_a")
+        b = _register(client, "follow_flow_b")
+
+        follow = client.post(f"/api/friends/{b['id']}/follow", headers=a["headers"])
+        assert follow.status_code == 201, follow.text
+
+        following = client.get("/api/friends/following", headers=a["headers"]).json()["following"]
+        assert any(u["id"] == b["id"] for u in following)
+
+        # One-way: b does not follow a.
+        b_following = client.get("/api/friends/following", headers=b["headers"]).json()["following"]
+        assert b_following == []
+
+        unfollow = client.delete(f"/api/friends/{b['id']}/follow", headers=a["headers"])
+        assert unfollow.status_code == 200, unfollow.text
+
+        following_after = client.get("/api/friends/following", headers=a["headers"]).json()["following"]
+        assert following_after == []
+
+        # Unfollowing again is a clean 404, not 500.
+        again = client.delete(f"/api/friends/{b['id']}/follow", headers=a["headers"])
+        assert again.status_code == 404
+
+    def test_follow_requires_auth(self):
+        client = TestClient(app)
+        b = _register(client, "follow_noauth_b")
+        resp = client.post(f"/api/friends/{b['id']}/follow", json={})
+        assert resp.status_code == 401
+
+
+class TestBlock:
+    def test_block_clears_existing_friendship_and_follow(self):
+        client = TestClient(app)
+        a = _register(client, "block_clear_a")
+        b = _register(client, "block_clear_b")
+
+        request_id = client.post(
+            "/api/friends/requests", json={"user_id": b["id"]}, headers=a["headers"]
+        ).json()["id"]
+        client.post(f"/api/friends/requests/{request_id}/accept", headers=b["headers"])
+        client.post(f"/api/friends/{a['id']}/follow", headers=b["headers"])
+
+        assert any(
+            u["id"] == b["id"] for u in client.get("/api/friends", headers=a["headers"]).json()["friends"]
+        )
+        assert any(
+            u["id"] == a["id"]
+            for u in client.get("/api/friends/following", headers=b["headers"]).json()["following"]
+        )
+
+        block = client.post(f"/api/friends/{b['id']}/block", headers=a["headers"])
+        assert block.status_code == 201, block.text
+
+        assert client.get("/api/friends", headers=a["headers"]).json()["friends"] == []
+        assert client.get("/api/friends", headers=b["headers"]).json()["friends"] == []
+        assert client.get("/api/friends/following", headers=b["headers"]).json()["following"] == []
+
+        blocked_list = client.get("/api/friends/blocked", headers=a["headers"]).json()["blocked"]
+        assert any(u["id"] == b["id"] for u in blocked_list)
+
+    def test_block_prevents_new_friend_request_and_follow(self):
+        client = TestClient(app)
+        a = _register(client, "block_prevent_a")
+        b = _register(client, "block_prevent_b")
+
+        client.post(f"/api/friends/{b['id']}/block", headers=a["headers"])
+
+        req = client.post("/api/friends/requests", json={"user_id": a["id"]}, headers=b["headers"])
+        assert req.status_code == 403
+
+        follow = client.post(f"/api/friends/{a['id']}/follow", headers=b["headers"])
+        assert follow.status_code == 403
+
+    def test_unblock_removes_block(self):
+        client = TestClient(app)
+        a = _register(client, "unblock_a")
+        b = _register(client, "unblock_b")
+
+        client.post(f"/api/friends/{b['id']}/block", headers=a["headers"])
+        unblock = client.delete(f"/api/friends/{b['id']}/block", headers=a["headers"])
+        assert unblock.status_code == 200, unblock.text
+
+        assert client.get("/api/friends/blocked", headers=a["headers"]).json()["blocked"] == []
+
+        # Idempotency: unblocking again is a clean 404, not 500.
+        again = client.delete(f"/api/friends/{b['id']}/block", headers=a["headers"])
+        assert again.status_code == 404
+
+        # After unblock, a fresh follow/request works again.
+        assert client.post(f"/api/friends/{a['id']}/follow", headers=b["headers"]).status_code == 201
+
+
+class TestDataIsolation:
+    def test_list_endpoints_are_scoped_to_caller(self):
+        """A third party's friends/following/blocked lists must never leak
+        into another user's response."""
+        client = TestClient(app)
+        a = _register(client, "iso_a")
+        b = _register(client, "iso_b")
+        c = _register(client, "iso_c")
+
+        request_id = client.post(
+            "/api/friends/requests", json={"user_id": b["id"]}, headers=a["headers"]
+        ).json()["id"]
+        client.post(f"/api/friends/requests/{request_id}/accept", headers=b["headers"])
+        client.post(f"/api/friends/{b['id']}/follow", headers=a["headers"])
+        client.post(f"/api/friends/{b['id']}/block", headers=c["headers"])
+
+        c_friends = client.get("/api/friends", headers=c["headers"]).json()["friends"]
+        c_following = client.get("/api/friends/following", headers=c["headers"]).json()["following"]
+        assert c_friends == []
+        assert c_following == []
+
+        # c's block of b must not appear in a's or b's blocked list.
+        a_blocked = client.get("/api/friends/blocked", headers=a["headers"]).json()["blocked"]
+        assert a_blocked == []
+
+    def test_requires_auth_on_all_endpoints(self):
+        client = TestClient(app)
+        assert client.get("/api/friends").status_code == 401
+        assert client.get("/api/friends/requests").status_code == 401
+        assert client.get("/api/friends/following").status_code == 401
+        assert client.get("/api/friends/blocked").status_code == 401
+        assert client.post("/api/friends/requests", json={"user_id": 1}).status_code == 401

backend/tests/test_social_models.py

@@ -0,0 +1,240 @@
+"""Model-level tests for the social graph: friendships, follows, blocks.
+
+app/models/social.py / alembic/versions/0007_add_social_graph_tables.py
+(docs/planning/social.md US-1). This is the models+migration task only --
+there are no API endpoints yet (a sibling task owns the router), so these
+tests exercise the ORM models and the real Postgres constraints directly
+rather than going through HTTP.
+"""
+
+import pytest
+from fastapi.testclient import TestClient
+from sqlalchemy import delete, select
+from sqlalchemy.exc import IntegrityError
+from sqlalchemy.ext.asyncio import async_sessionmaker, create_async_engine
+from sqlalchemy.pool import NullPool
+
+from app.config import settings
+from app.main import app
+from app.models.social import Friendship, Follow, Block, FriendshipStatus
+from app.models.user import User
+
+
+def _register(client: TestClient, username: str) -> int:
+    resp = client.post(
+        "/api/auth/register",
+        json={
+            "username": username,
+            "email": f"{username}@example.com",
+            "password": "secret123",
+            "date_of_birth": "1990-01-01",
+        },
+    )
+    assert resp.status_code == 201, resp.text
+    headers = {"Authorization": f"Bearer {resp.json()['access_token']}"}
+    me = client.get("/api/users/me", headers=headers)
+    assert me.status_code == 200, me.text
+    return me.json()["id"]
+
+
+def _session_factory():
+    engine = create_async_engine(settings.DATABASE_URL, poolclass=NullPool)
+    return engine, async_sessionmaker(engine, expire_on_commit=False)
+
+
+class TestFriendshipRequestAccept:
+    async def test_request_defaults_to_pending(self):
+        client = TestClient(app)
+        a = _register(client, "sg_fr_a1")
+        b = _register(client, "sg_fr_b1")
+
+        engine, factory = _session_factory()
+        try:
+            async with factory() as session:
+                fr = Friendship(requester_id=a, addressee_id=b)
+                session.add(fr)
+                await session.commit()
+                await session.refresh(fr)
+                assert fr.status == FriendshipStatus.PENDING
+                assert fr.requester_id == a
+                assert fr.addressee_id == b
+        finally:
+            await engine.dispose()
+
+    async def test_accept_updates_status(self):
+        client = TestClient(app)
+        a = _register(client, "sg_fr_a2")
+        b = _register(client, "sg_fr_b2")
+
+        engine, factory = _session_factory()
+        try:
+            async with factory() as session:
+                fr = Friendship(requester_id=a, addressee_id=b)
+                session.add(fr)
+                await session.commit()
+                fr_id = fr.id
+
+            async with factory() as session:
+                fr = await session.get(Friendship, fr_id)
+                fr.status = FriendshipStatus.ACCEPTED
+                await session.commit()
+
+            async with factory() as session:
+                fr = await session.get(Friendship, fr_id)
+                assert fr.status == FriendshipStatus.ACCEPTED
+        finally:
+            await engine.dispose()
+
+
+class TestUniquePairConstraints:
+    async def test_duplicate_friendship_pair_rejected(self):
+        client = TestClient(app)
+        a = _register(client, "sg_uq_fr_a")
+        b = _register(client, "sg_uq_fr_b")
+
+        engine, factory = _session_factory()
+        try:
+            async with factory() as session:
+                session.add(Friendship(requester_id=a, addressee_id=b))
+                await session.commit()
+
+            async with factory() as session:
+                session.add(Friendship(requester_id=a, addressee_id=b))
+                with pytest.raises(IntegrityError):
+                    await session.commit()
+        finally:
+            await engine.dispose()
+
+    async def test_duplicate_follow_pair_rejected(self):
+        client = TestClient(app)
+        a = _register(client, "sg_uq_fw_a")
+        b = _register(client, "sg_uq_fw_b")
+
+        engine, factory = _session_factory()
+        try:
+            async with factory() as session:
+                session.add(Follow(follower_id=a, followed_id=b))
+                await session.commit()
+
+            async with factory() as session:
+                session.add(Follow(follower_id=a, followed_id=b))
+                with pytest.raises(IntegrityError):
+                    await session.commit()
+        finally:
+            await engine.dispose()
+
+    async def test_duplicate_block_pair_rejected(self):
+        client = TestClient(app)
+        a = _register(client, "sg_uq_bl_a")
+        b = _register(client, "sg_uq_bl_b")
+
+        engine, factory = _session_factory()
+        try:
+            async with factory() as session:
+                session.add(Block(blocker_id=a, blocked_id=b))
+                await session.commit()
+
+            async with factory() as session:
+                session.add(Block(blocker_id=a, blocked_id=b))
+                with pytest.raises(IntegrityError):
+                    await session.commit()
+        finally:
+            await engine.dispose()
+
+
+class TestFollow:
+    async def test_create_follow(self):
+        client = TestClient(app)
+        a = _register(client, "sg_follow_a")
+        b = _register(client, "sg_follow_b")
+
+        engine, factory = _session_factory()
+        try:
+            async with factory() as session:
+                session.add(Follow(follower_id=a, followed_id=b))
+                await session.commit()
+
+            async with factory() as session:
+                rows = (await session.execute(
+                    select(Follow).where(Follow.follower_id == a, Follow.followed_id == b)
+                )).scalars().all()
+                assert len(rows) == 1
+        finally:
+            await engine.dispose()
+
+
+class TestBlock:
+    async def test_create_block(self):
+        client = TestClient(app)
+        a = _register(client, "sg_block_a")
+        b = _register(client, "sg_block_b")
+
+        engine, factory = _session_factory()
+        try:
+            async with factory() as session:
+                session.add(Block(blocker_id=a, blocked_id=b))
+                await session.commit()
+
+            async with factory() as session:
+                rows = (await session.execute(
+                    select(Block).where(Block.blocker_id == a, Block.blocked_id == b)
+                )).scalars().all()
+                assert len(rows) == 1
+        finally:
+            await engine.dispose()
+
+
+class TestCascadeDelete:
+    async def test_deleting_user_removes_rows_in_all_three_tables(self):
+        """Deleting a user removes friendships/follows/blocks referencing them
+        in *either* FK column, via the real DB ON DELETE CASCADE (deleted with
+        a Core statement, bypassing any ORM-level cascade, to prove the
+        database constraint itself does the job)."""
+        client = TestClient(app)
+        a = _register(client, "sg_cascade_a")
+        b = _register(client, "sg_cascade_b")
+        c = _register(client, "sg_cascade_c")
+
+        engine, factory = _session_factory()
+        try:
+            async with factory() as session:
+                # a as requester/follower/blocker, and also as addressee (c -> a)
+                session.add(Friendship(requester_id=a, addressee_id=b))
+                session.add(Friendship(requester_id=c, addressee_id=a))
+                session.add(Follow(follower_id=a, followed_id=b))
+                session.add(Follow(follower_id=c, followed_id=a))
+                session.add(Block(blocker_id=a, blocked_id=b))
+                session.add(Block(blocker_id=c, blocked_id=a))
+                await session.commit()
+
+            async with factory() as session:
+                await session.execute(delete(User).where(User.id == a))
+                await session.commit()
+
+            async with factory() as session:
+                friendships = (await session.execute(
+                    select(Friendship).where(
+                        (Friendship.requester_id == a) | (Friendship.addressee_id == a)
+                    )
+                )).scalars().all()
+                follows = (await session.execute(
+                    select(Follow).where(
+                        (Follow.follower_id == a) | (Follow.followed_id == a)
+                    )
+                )).scalars().all()
+                blocks = (await session.execute(
+                    select(Block).where(
+                        (Block.blocker_id == a) | (Block.blocked_id == a)
+                    )
+                )).scalars().all()
+                assert friendships == []
+                assert follows == []
+                assert blocks == []
+
+                # Unrelated rows (b, c only) survive.
+                remaining_users = (await session.execute(
+                    select(User.id).where(User.id.in_([b, c]))
+                )).scalars().all()
+                assert set(remaining_users) == {b, c}
+        finally:
+            await engine.dispose()

backend/tests/test_text_filter.py

@@ -0,0 +1,194 @@
+"""Unit tests for app.services.text_filter (docs/planning/social.md §4/§5 US-4).
+
+Pure, side-effect-free service -- no DB/Redis fixtures needed.
+"""
+
+from __future__ import annotations
+
+from pathlib import Path
+
+import pytest
+
+from app.services.text_filter import (
+    DEFAULT_TERMS_PATH,
+    FilterAction,
+    FilterMode,
+    FilterResult,
+    ListBasedTextFilter,
+    TextFilter,
+    default_text_filter,
+    load_terms,
+)
+
+
+@pytest.fixture
+def redact_filter() -> ListBasedTextFilter:
+    return ListBasedTextFilter(terms=["badword", "shoot"], mode=FilterMode.REDACT)
+
+
+@pytest.fixture
+def reject_filter() -> ListBasedTextFilter:
+    return ListBasedTextFilter(terms=["badword", "shoot"], mode=FilterMode.REJECT)
+
+
+class TestAllowPath:
+    def test_clean_text_is_allowed_unchanged(self, redact_filter: ListBasedTextFilter) -> None:
+        result = redact_filter.check("hello there, how are you today?")
+        assert result.action is FilterAction.ALLOW
+        assert result.filtered_text == "hello there, how are you today?"
+        assert result.matched_terms == ()
+
+    def test_message_with_no_matches(self, reject_filter: ListBasedTextFilter) -> None:
+        # Distinct from the clean-text case above: exercises the reject-mode
+        # filter's no-match path specifically (mode should not matter when
+        # nothing matches).
+        text = "let's meet at the plaza around noon"
+        result = reject_filter.check(text)
+        assert result.action is FilterAction.ALLOW
+        assert result.filtered_text == text
+        assert result.matched_terms == ()
+
+
+class TestRedactPath:
+    def test_exact_match_is_redacted(self, redact_filter: ListBasedTextFilter) -> None:
+        result = redact_filter.check("don't be a badword about it")
+        assert result.action is FilterAction.REDACT
+        assert result.matched_terms == ("badword",)
+        assert "badword" not in result.filtered_text
+        assert result.filtered_text == "don't be a ******* about it"
+
+    def test_multiple_distinct_matches(self, redact_filter: ListBasedTextFilter) -> None:
+        result = redact_filter.check("badword, don't shoot!")
+        assert result.action is FilterAction.REDACT
+        assert set(result.matched_terms) == {"badword", "shoot"}
+        assert "badword" not in result.filtered_text
+        assert "shoot" not in result.filtered_text
+        # Length is preserved (asterisks replace matched spans 1:1).
+        assert len(result.filtered_text) == len("badword, don't shoot!")
+
+    def test_redaction_char_is_configurable(self) -> None:
+        f = ListBasedTextFilter(terms=["badword"], mode=FilterMode.REDACT, redaction_char="#")
+        result = f.check("that's a badword thing to say")
+        assert result.filtered_text == "that's a ####### thing to say"
+
+
+class TestRejectPath:
+    def test_match_is_rejected_and_text_left_intact(self, reject_filter: ListBasedTextFilter) -> None:
+        text = "stop, badword!"
+        result = reject_filter.check(text)
+        assert result.action is FilterAction.REJECT
+        assert result.matched_terms == ("badword",)
+        # Reject mode does not mutate the text -- callers are expected to
+        # not store/deliver it at all, based on `action`.
+        assert result.filtered_text == text
+
+
+class TestNormalization:
+    def test_leetspeak_variant_is_caught(self, redact_filter: ListBasedTextFilter) -> None:
+        # "b4dw0rd" -> normalizes to "badword" via the leet map (4->a, 0->o).
+        result = redact_filter.check("you're being a b4dw0rd right now")
+        assert result.action is FilterAction.REDACT
+        assert result.matched_terms == ("badword",)
+
+    def test_separators_between_letters_are_stripped(self, redact_filter: ListBasedTextFilter) -> None:
+        result = redact_filter.check("that is b.a.d.w.o.r.d behavior")
+        assert result.action is FilterAction.REDACT
+        assert result.matched_terms == ("badword",)
+
+    def test_spacing_between_letters_is_stripped(self, redact_filter: ListBasedTextFilter) -> None:
+        result = redact_filter.check("b a d w o r d, seriously")
+        assert result.action is FilterAction.REDACT
+        assert result.matched_terms == ("badword",)
+
+    def test_case_folding(self, redact_filter: ListBasedTextFilter) -> None:
+        result = redact_filter.check("BADWORD in all caps")
+        assert result.action is FilterAction.REDACT
+        assert result.matched_terms == ("badword",)
+
+    def test_symbol_lookalikes(self) -> None:
+        # @ -> a, $ -> s: "@ss" should normalize to "ass".
+        f = ListBasedTextFilter(terms=["ass"], mode=FilterMode.REDACT)
+        result = f.check("what an @$$ move")
+        assert result.action is FilterAction.REDACT
+        assert result.matched_terms == ("ass",)
+
+
+class TestEmptyAndWhitespace:
+    def test_empty_string(self, redact_filter: ListBasedTextFilter) -> None:
+        result = redact_filter.check("")
+        assert result.action is FilterAction.ALLOW
+        assert result.filtered_text == ""
+        assert result.matched_terms == ()
+
+    def test_whitespace_only_string(self, redact_filter: ListBasedTextFilter) -> None:
+        text = "   \t\n  "
+        result = redact_filter.check(text)
+        assert result.action is FilterAction.ALLOW
+        assert result.filtered_text == text
+        assert result.matched_terms == ()
+
+    def test_punctuation_only_string_has_nothing_to_normalize(self, redact_filter: ListBasedTextFilter) -> None:
+        # No alnum characters survive normalization at all -- must not
+        # crash on an empty normalized string / empty index_map.
+        result = redact_filter.check("...!!!???")
+        assert result.action is FilterAction.ALLOW
+        assert result.matched_terms == ()
+
+
+class TestConfigurability:
+    def test_custom_term_list_is_used_instead_of_default(self) -> None:
+        f = ListBasedTextFilter(terms=["zzzcustomzzz"], mode=FilterMode.REDACT)
+        result = f.check("this contains zzzcustomzzz right here")
+        assert result.action is FilterAction.REDACT
+        assert result.matched_terms == ("zzzcustomzzz",)
+        # Default list terms should NOT match since we overrode the list.
+        result2 = f.check("this is fucking unrelated")
+        assert result2.action is FilterAction.ALLOW
+
+    def test_duplicate_and_blank_terms_are_deduped(self) -> None:
+        f = ListBasedTextFilter(terms=["badword", "badword", "  ", ""], mode=FilterMode.REDACT)
+        assert f._terms == ("badword",)
+
+    def test_default_terms_file_loads_and_is_nonempty(self) -> None:
+        terms = load_terms()
+        assert isinstance(terms, list)
+        assert len(terms) > 0
+        assert all(isinstance(t, str) and t for t in terms)
+
+    def test_default_terms_path_exists(self) -> None:
+        assert DEFAULT_TERMS_PATH.exists()
+        assert DEFAULT_TERMS_PATH.suffix == ".json"
+
+    def test_load_terms_from_explicit_path(self, tmp_path: Path) -> None:
+        custom = tmp_path / "custom_terms.json"
+        custom.write_text('{"terms": ["foo", "bar"]}', encoding="utf-8")
+        assert load_terms(custom) == ["foo", "bar"]
+
+    def test_default_text_filter_factory_matches_default_list(self) -> None:
+        f = default_text_filter(mode=FilterMode.REJECT)
+        result = f.check("that's fucking ridiculous")
+        assert result.action is FilterAction.REJECT
+        assert "fuck" in result.matched_terms
+
+
+class TestProtocol:
+    def test_list_based_filter_satisfies_text_filter_protocol(self, redact_filter: ListBasedTextFilter) -> None:
+        assert isinstance(redact_filter, TextFilter)
+
+    def test_check_returns_filter_result(self, redact_filter: ListBasedTextFilter) -> None:
+        result = redact_filter.check("hi")
+        assert isinstance(result, FilterResult)
+
+    def test_a_third_party_style_implementation_satisfies_the_protocol(self) -> None:
+        # Demonstrates the extension point: any object with a matching
+        # `check` method satisfies TextFilter without inheriting from
+        # anything -- this is how a future third-party provider would plug
+        # in without touching this module.
+        class AlwaysAllow:
+            def check(self, text: str) -> FilterResult:
+                return FilterResult(action=FilterAction.ALLOW, filtered_text=text, matched_terms=())
+
+        provider: TextFilter = AlwaysAllow()
+        assert isinstance(provider, TextFilter)
+        result = provider.check("anything at all, even fuck")
+        assert result.action is FilterAction.ALLOW

backend/tests/test_wallet_api.py

@@ -0,0 +1,135 @@
+"""Integration tests for Wallet service and API endpoints.
+
+docs/planning/economy.md US-1 (task 909e3e9a59af).
+"""
+
+import pytest
+from fastapi.testclient import TestClient
+from sqlalchemy.ext.asyncio import async_sessionmaker, create_async_engine
+from sqlalchemy.pool import NullPool
+
+from app.config import settings
+from app.main import app
+from app.models.wallet import TransactionType
+from app.services.wallet import InsufficientFundsError, InvalidAmountError, wallet_service
+
+
+def _register(client: TestClient, username: str) -> tuple[int, dict[str, str]]:
+    resp = client.post(
+        "/api/auth/register",
+        json={
+            "username": username,
+            "email": f"{username}@example.com",
+            "password": "secret123",
+            "date_of_birth": "1990-01-01",
+        },
+    )
+    assert resp.status_code == 201, resp.text
+    token = resp.json()["access_token"]
+    headers = {"Authorization": f"Bearer {token}"}
+    me = client.get("/api/users/me", headers=headers)
+    assert me.status_code == 200, me.text
+    return me.json()["id"], headers
+
+
+def _session_factory():
+    engine = create_async_engine(settings.DATABASE_URL, poolclass=NullPool)
+    return engine, async_sessionmaker(engine, expire_on_commit=False)
+
+
+def test_wallet_unauthorized():
+    client = TestClient(app)
+    resp = client.get("/api/wallet")
+    assert resp.status_code == 401
+
+    resp = client.get("/api/wallet/transactions")
+    assert resp.status_code == 401
+
+
+def test_get_wallet_lazy_creation():
+    client = TestClient(app)
+    uid, headers = _register(client, "wallet_api_user_1")
+
+    resp = client.get("/api/wallet", headers=headers)
+    assert resp.status_code == 200, resp.text
+    data = resp.json()
+    assert data["user_id"] == uid
+    assert data["balance"] == 0
+    assert data["id"] is not None
+
+
+@pytest.mark.asyncio
+async def test_wallet_service_credit_and_debit_flow():
+    client = TestClient(app)
+    uid, headers = _register(client, "wallet_api_user_2")
+
+    engine, sf = _session_factory()
+    try:
+        async with sf() as session:
+            # 1. Credit
+            wallet, tx = await wallet_service.credit(
+                session,
+                user_id=uid,
+                amount=1000,
+                tx_type=TransactionType.credit_purchase,
+                reference_type="test_ref",
+                reference_id="ref_1",
+                idempotency_key="credit_idemp_1",
+            )
+            assert wallet.balance == 1000
+            assert tx.amount == 1000
+            assert tx.balance_after == 1000
+
+            # 2. Idempotent re-credit does not increase balance
+            wallet2, tx2 = await wallet_service.credit(
+                session,
+                user_id=uid,
+                amount=1000,
+                tx_type=TransactionType.credit_purchase,
+                idempotency_key="credit_idemp_1",
+            )
+            assert wallet2.balance == 1000
+            assert tx2.id == tx.id
+
+            # 3. Debit
+            wallet3, tx3 = await wallet_service.debit(
+                session,
+                user_id=uid,
+                amount=400,
+                tx_type=TransactionType.marketplace_purchase,
+                reference_type="purchase",
+                reference_id="item_42",
+                idempotency_key="debit_idemp_1",
+            )
+            assert wallet3.balance == 600
+            assert tx3.amount == -400
+            assert tx3.balance_after == 600
+
+            # 4. Over-debit raises InsufficientFundsError
+            with pytest.raises(InsufficientFundsError):
+                await wallet_service.debit(
+                    session,
+                    user_id=uid,
+                    amount=1000,
+                    tx_type=TransactionType.marketplace_purchase,
+                )
+
+            # Balance remains 600
+            w_check = await wallet_service.get_or_create_wallet(session, uid)
+            assert w_check.balance == 600
+    finally:
+        await engine.dispose()
+
+    # Verify via API
+    resp = client.get("/api/wallet", headers=headers)
+    assert resp.status_code == 200
+    assert resp.json()["balance"] == 600
+
+    resp_tx = client.get("/api/wallet/transactions", headers=headers)
+    assert resp_tx.status_code == 200
+    tx_data = resp_tx.json()
+    assert tx_data["total"] == 2
+    assert len(tx_data["transactions"]) == 2
+    # Newest first: debit (-400) first, then credit (+1000)
+    assert tx_data["transactions"][0]["amount"] == -400
+    assert tx_data["transactions"][1]["amount"] == 1000

backend/tests/test_wallet_models.py

@@ -0,0 +1,141 @@
+"""Model-level integration tests for Wallets and Transaction ledger.
+
+docs/planning/economy.md US-1 (task 8343bc0a730f).
+"""
+
+import pytest
+from fastapi.testclient import TestClient
+from sqlalchemy import select
+from sqlalchemy.exc import IntegrityError
+from sqlalchemy.ext.asyncio import async_sessionmaker, create_async_engine
+from sqlalchemy.pool import NullPool
+
+from app.config import settings
+from app.main import app
+from app.models.wallet import Wallet, Transaction, TransactionType
+from app.models.user import User
+
+
+def _register(client: TestClient, username: str) -> int:
+    resp = client.post(
+        "/api/auth/register",
+        json={
+            "username": username,
+            "email": f"{username}@example.com",
+            "password": "secret123",
+            "date_of_birth": "1990-01-01",
+        },
+    )
+    assert resp.status_code == 201, resp.text
+    headers = {"Authorization": f"Bearer {resp.json()['access_token']}"}
+    me = client.get("/api/users/me", headers=headers)
+    assert me.status_code == 200, me.text
+    return me.json()["id"]
+
+
+def _session_factory():
+    engine = create_async_engine(settings.DATABASE_URL, poolclass=NullPool)
+    return engine, async_sessionmaker(engine, expire_on_commit=False)
+
+
+@pytest.mark.asyncio
+async def test_wallet_creation_and_defaults():
+    client = TestClient(app)
+    uid = _register(client, "wallet_user_1")
+    engine, sf = _session_factory()
+    try:
+        async with sf() as session:
+            wallet = Wallet(user_id=uid)
+            session.add(wallet)
+            await session.commit()
+            await session.refresh(wallet)
+
+            assert wallet.id is not None
+            assert wallet.user_id == uid
+            assert wallet.balance == 0
+            assert wallet.created_at is not None
+            assert wallet.updated_at is not None
+    finally:
+        await engine.dispose()
+
+
+@pytest.mark.asyncio
+async def test_wallet_unique_user_id():
+    client = TestClient(app)
+    uid = _register(client, "wallet_user_2")
+    engine, sf = _session_factory()
+    try:
+        async with sf() as session:
+            w1 = Wallet(user_id=uid)
+            session.add(w1)
+            await session.commit()
+
+        async with sf() as session:
+            w2 = Wallet(user_id=uid)
+            session.add(w2)
+            with pytest.raises(IntegrityError):
+                await session.commit()
+    finally:
+        await engine.dispose()
+
+
+@pytest.mark.asyncio
+async def test_wallet_non_negative_balance_constraint():
+    client = TestClient(app)
+    uid = _register(client, "wallet_user_3")
+    engine, sf = _session_factory()
+    try:
+        async with sf() as session:
+            w = Wallet(user_id=uid, balance=-50)
+            session.add(w)
+            with pytest.raises(IntegrityError):
+                await session.commit()
+    finally:
+        await engine.dispose()
+
+
+@pytest.mark.asyncio
+async def test_transaction_ledger_and_idempotency():
+    client = TestClient(app)
+    uid = _register(client, "wallet_user_4")
+    engine, sf = _session_factory()
+    try:
+        async with sf() as session:
+            wallet = Wallet(user_id=uid, balance=500)
+            session.add(wallet)
+            await session.commit()
+            await session.refresh(wallet)
+
+            tx1 = Transaction(
+                wallet_id=wallet.id,
+                type=TransactionType.credit_purchase,
+                amount=500,
+                balance_after=500,
+                reference_type="purchase_session",
+                reference_id="sess_123",
+                idempotency_key="idemp_key_001",
+                metadata_json={"payment_method": "simulated"},
+            )
+            session.add(tx1)
+            await session.commit()
+            await session.refresh(tx1)
+
+            assert tx1.id is not None
+            assert tx1.type == TransactionType.credit_purchase
+            assert tx1.amount == 500
+            assert tx1.balance_after == 500
+
+        # Duplicate idempotency_key must raise IntegrityError
+        async with sf() as session:
+            tx2 = Transaction(
+                wallet_id=wallet.id,
+                type=TransactionType.credit_purchase,
+                amount=500,
+                balance_after=1000,
+                idempotency_key="idemp_key_001",
+            )
+            session.add(tx2)
+            with pytest.raises(IntegrityError):
+                await session.commit()
+    finally:
+        await engine.dispose()

backend/tests/test_ws_gateway.py

@@ -0,0 +1,222 @@
+"""Integration tests for real-time WebSocket gateway:
+- Authentication (query param + first auth frame)
+- Rejection of unauthenticated clients
+- Presence on connect / disconnect
+- Subscriptions to world chat channels and DM conversations
+- Real-time event delivery from REST endpoints
+- Reconnect and ping/pong
+"""
+
+import asyncio
+import time
+import pytest
+from fastapi.testclient import TestClient
+from starlette.websockets import WebSocketDisconnect
+
+from app.main import app
+from app.services.presence import presence_store
+
+
+def _register(client: TestClient, username: str) -> dict:
+    resp = client.post(
+        "/api/auth/register",
+        json={
+            "username": username,
+            "email": f"{username}@example.com",
+            "password": "secret123",
+            "date_of_birth": "1990-01-01",
+        },
+    )
+    assert resp.status_code == 201, resp.text
+    token = resp.json()["access_token"]
+    headers = {"Authorization": f"Bearer {token}"}
+    me = client.get("/api/users/me", headers=headers)
+    assert me.status_code == 200, me.text
+    return {"headers": headers, "token": token, "id": me.json()["id"], "username": username}
+
+
+def _make_world(client: TestClient, headers: dict, visibility: str = "public") -> int:
+    r = client.post("/api/worlds/", headers=headers, json={"name": "WSWorld", "visibility": visibility})
+    assert r.status_code == 201, r.text
+    return r.json()["id"]
+
+
+def _make_friends(client: TestClient, user_a: dict, user_b: dict) -> None:
+    req = client.post("/api/friends/requests", json={"user_id": user_b["id"]}, headers=user_a["headers"])
+    assert req.status_code == 201, req.text
+    req_id = req.json()["id"]
+    acc = client.post(f"/api/friends/requests/{req_id}/accept", headers=user_b["headers"])
+    assert acc.status_code == 200, acc.text
+
+
+class TestWebSocketAuth:
+    def test_unauthenticated_connection_rejected(self):
+        client = TestClient(app)
+        # Invalid query param token rejected
+        with pytest.raises(WebSocketDisconnect) as exc:
+            with client.websocket_connect("/api/ws?token=invalid_token"):
+                pass
+        assert exc.value.code == 1008
+
+        # First frame with invalid token rejected
+        with pytest.raises(WebSocketDisconnect) as exc2:
+            with client.websocket_connect("/api/ws") as ws:
+                ws.send_json({"type": "auth", "token": "invalid_token"})
+                ws.receive_json()
+                ws.receive_json()
+        assert exc2.value.code == 1008
+
+    def test_auth_via_query_param(self):
+        client = TestClient(app)
+        alice = _register(client, "ws_auth_alice")
+
+        with client.websocket_connect(f"/api/ws?token={alice['token']}") as ws:
+            msg = ws.receive_json()
+            assert msg["type"] == "auth_ok"
+            assert msg["user_id"] == alice["id"]
+            assert msg["username"] == "ws_auth_alice"
+
+    def test_auth_via_first_message(self):
+        client = TestClient(app)
+        bob = _register(client, "ws_auth_bob")
+
+        with client.websocket_connect("/api/ws") as ws:
+            ws.send_json({"type": "auth", "token": bob["token"]})
+            msg = ws.receive_json()
+            assert msg["type"] == "auth_ok"
+            assert msg["user_id"] == bob["id"]
+            assert msg["username"] == "ws_auth_bob"
+
+
+class TestWebSocketPresence:
+    def test_presence_on_connect_and_disconnect(self):
+        import threading
+        client = TestClient(app)
+        alice = _register(client, "ws_pres_alice")
+        bob = _register(client, "ws_pres_bob")
+        _make_friends(client, alice, bob)
+
+        # Initially both offline
+        assert not asyncio.run(presence_store.is_online(alice["id"]))
+
+        # Bob connects and listens for presence events
+        bob_events = []
+
+        def run_alice():
+            time.sleep(0.2)
+            c_alice = TestClient(app)
+            with c_alice.websocket_connect(f"/api/ws?token={alice['token']}") as alice_ws:
+                assert alice_ws.receive_json()["type"] == "auth_ok"
+                time.sleep(0.3)
+                alice_ws.close()
+                time.sleep(0.3)
+
+        with client.websocket_connect(f"/api/ws?token={bob['token']}") as bob_ws:
+            assert bob_ws.receive_json()["type"] == "auth_ok"
+
+            alice_thread = threading.Thread(target=run_alice)
+            alice_thread.start()
+
+            # Bob receives Alice's online event
+            online_event = bob_ws.receive_json()
+            assert online_event["type"] == "presence"
+            assert online_event["user_id"] == alice["id"]
+            assert online_event["is_online"] is True
+
+            alice_thread.join()
+
+            # Bob receives Alice's offline event
+            offline_event = bob_ws.receive_json()
+            assert offline_event["type"] == "presence"
+            assert offline_event["user_id"] == alice["id"]
+            assert offline_event["is_online"] is False
+
+        assert not asyncio.run(presence_store.is_online(alice["id"]))
+
+
+class TestWebSocketChatDelivery:
+    def test_world_chat_subscription_and_delivery(self):
+        client = TestClient(app)
+        alice = _register(client, "ws_chat_alice")
+        bob = _register(client, "ws_chat_bob")
+        world_id = _make_world(client, alice["headers"])
+
+        with client.websocket_connect(f"/api/ws?token={bob['token']}") as bob_ws:
+            assert bob_ws.receive_json()["type"] == "auth_ok"
+
+            # Bob subscribes to world
+            bob_ws.send_json({"type": "subscribe_world", "world_id": world_id})
+            sub_ack = bob_ws.receive_json()
+            assert sub_ack["type"] == "subscribed"
+            assert sub_ack["channel"] == "world"
+            assert sub_ack["id"] == world_id
+
+            # Alice posts message to world via REST
+            rest_resp = client.post(
+                f"/api/chat/world/{world_id}/messages",
+                headers=alice["headers"],
+                json={"body": "Hello real-time world!"},
+            )
+            assert rest_resp.status_code == 201, rest_resp.text
+            msg_id = rest_resp.json()["id"]
+
+            # Bob receives message in real time over WebSocket
+            ws_msg = bob_ws.receive_json()
+            assert ws_msg["type"] == "world_chat"
+            assert ws_msg["world_id"] == world_id
+            assert ws_msg["message"]["id"] == msg_id
+            assert ws_msg["message"]["body"] == "Hello real-time world!"
+            assert ws_msg["message"]["author"]["username"] == "ws_chat_alice"
+
+    def test_dm_chat_subscription_and_delivery(self):
+        client = TestClient(app)
+        alice = _register(client, "ws_dm_alice")
+        bob = _register(client, "ws_dm_bob")
+
+        # Initial DM to create conversation
+        init_dm = client.post(
+            f"/api/chat/dm/{bob['id']}/messages",
+            headers=alice["headers"],
+            json={"body": "First DM to initiate"},
+        )
+        assert init_dm.status_code == 201, init_dm.text
+        conv_id = init_dm.json()["conversation_id"]
+
+        with client.websocket_connect(f"/api/ws?token={bob['token']}") as bob_ws:
+            assert bob_ws.receive_json()["type"] == "auth_ok"
+
+            # Bob subscribes to this conversation
+            bob_ws.send_json({"type": "subscribe_dm", "conversation_id": conv_id})
+            sub_ack = bob_ws.receive_json()
+            assert sub_ack["type"] == "subscribed"
+            assert sub_ack["channel"] == "dm"
+            assert sub_ack["id"] == conv_id
+
+            # Alice sends another DM via REST
+            rest_dm = client.post(
+                f"/api/chat/dm/{bob['id']}/messages",
+                headers=alice["headers"],
+                json={"body": "Real-time DM ping!"},
+            )
+            assert rest_dm.status_code == 201, rest_dm.text
+
+            # Bob receives real-time DM over WebSocket
+            ws_dm = bob_ws.receive_json()
+            assert ws_dm["type"] == "dm_chat"
+            assert ws_dm["conversation_id"] == conv_id
+            assert ws_dm["message"]["body"] == "Real-time DM ping!"
+
+
+class TestWebSocketPingAndHeartbeat:
+    def test_ping_pong_and_heartbeat(self):
+        client = TestClient(app)
+        alice = _register(client, "ws_ping_alice")
+
+        with client.websocket_connect(f"/api/ws?token={alice['token']}") as ws:
+            assert ws.receive_json()["type"] == "auth_ok"
+
+            ws.send_json({"type": "ping"})
+            assert ws.receive_json()["type"] == "pong"
+
+            ws.send_json({"type": "heartbeat"})
+            assert ws.receive_json()["type"] == "heartbeat_ack"

project.godot

@@ -45,6 +45,16 @@ move_down={
 "events": [Object(InputEventKey,"resource_local_to_scene":false,"resource_name":"","device":-1,"window_id":0,"alt_pressed":false,"shift_pressed":false,"ctrl_pressed":false,"meta_pressed":false,"pressed":false,"keycode":0,"physical_keycode":83,"key_label":0,"unicode":115,"location":0,"echo":false,"script":null)
 ]
 }
+interact={
+"deadzone": 0.5,
+"events": [Object(InputEventKey,"resource_local_to_scene":false,"resource_name":"","device":-1,"window_id":0,"alt_pressed":false,"shift_pressed":false,"ctrl_pressed":false,"meta_pressed":false,"pressed":false,"keycode":0,"physical_keycode":69,"key_label":0,"unicode":101,"location":0,"echo":false,"script":null)
+]
+}
+toggle_build_mode={
+"deadzone": 0.5,
+"events": [Object(InputEventKey,"resource_local_to_scene":false,"resource_name":"","device":-1,"window_id":0,"alt_pressed":false,"shift_pressed":false,"ctrl_pressed":false,"meta_pressed":false,"pressed":false,"keycode":0,"physical_keycode":4194333,"key_label":0,"unicode":0,"location":0,"echo":false,"script":null)
+]
+}
 
 [physics]
 

scenes/chat_ui.tscn

@@ -0,0 +1,202 @@
+[gd_scene load_steps=2 format=3]
+
+[ext_resource type="Script" path="res://scripts/chat_ui.gd" id="1_cu"]
+
+[node name="ChatUI" type="Control"]
+layout_mode = 3
+anchors_preset = 15
+anchor_right = 1.0
+anchor_bottom = 1.0
+grow_horizontal = 2
+grow_vertical = 2
+script = ExtResource("1_cu")
+
+[node name="VBoxContainer" type="VBoxContainer" parent="."]
+layout_mode = 1
+anchors_preset = 15
+anchor_right = 1.0
+anchor_bottom = 1.0
+offset_left = 32.0
+offset_top = 32.0
+offset_right = -32.0
+offset_bottom = -32.0
+grow_horizontal = 2
+grow_vertical = 2
+theme_override_constants/separation = 12
+
+[node name="HeaderHBox" type="HBoxContainer" parent="VBoxContainer"]
+layout_mode = 2
+theme_override_constants/separation = 16
+
+[node name="BackButton" type="Button" parent="VBoxContainer/HeaderHBox"]
+custom_minimum_size = Vector2(100, 36)
+layout_mode = 2
+text = "< Back"
+
+[node name="TitleLabel" type="Label" parent="VBoxContainer/HeaderHBox"]
+layout_mode = 2
+size_flags_horizontal = 3
+theme_override_font_sizes/font_size = 26
+text = "Chat & Messaging"
+horizontal_alignment = 1
+
+[node name="RefreshButton" type="Button" parent="VBoxContainer/HeaderHBox"]
+custom_minimum_size = Vector2(100, 36)
+layout_mode = 2
+text = "Refresh"
+
+[node name="StatusMessageLabel" type="Label" parent="VBoxContainer"]
+layout_mode = 2
+horizontal_alignment = 1
+
+[node name="TabContainer" type="TabContainer" parent="VBoxContainer"]
+layout_mode = 2
+size_flags_vertical = 3
+current_tab = 0
+
+[node name="WorldChat" type="VBoxContainer" parent="VBoxContainer/TabContainer"]
+layout_mode = 2
+theme_override_constants/separation = 8
+metadata/_tab_index = 0
+
+[node name="ControlsHBox" type="HBoxContainer" parent="VBoxContainer/TabContainer/WorldChat"]
+layout_mode = 2
+theme_override_constants/separation = 8
+
+[node name="WorldPrefix" type="Label" parent="VBoxContainer/TabContainer/WorldChat/ControlsHBox"]
+layout_mode = 2
+text = "World ID:"
+
+[node name="WorldIdEdit" type="LineEdit" parent="VBoxContainer/TabContainer/WorldChat/ControlsHBox"]
+custom_minimum_size = Vector2(120, 32)
+layout_mode = 2
+text = "1"
+
+[node name="JoinChatButton" type="Button" parent="VBoxContainer/TabContainer/WorldChat/ControlsHBox"]
+custom_minimum_size = Vector2(110, 32)
+layout_mode = 2
+text = "Switch Channel"
+
+[node name="Scroll" type="ScrollContainer" parent="VBoxContainer/TabContainer/WorldChat"]
+layout_mode = 2
+size_flags_vertical = 3
+
+[node name="MessagesList" type="VBoxContainer" parent="VBoxContainer/TabContainer/WorldChat/Scroll"]
+layout_mode = 2
+size_flags_horizontal = 3
+theme_override_constants/separation = 8
+
+[node name="SendHBox" type="HBoxContainer" parent="VBoxContainer/TabContainer/WorldChat"]
+layout_mode = 2
+theme_override_constants/separation = 8
+
+[node name="MessageInput" type="LineEdit" parent="VBoxContainer/TabContainer/WorldChat/SendHBox"]
+layout_mode = 2
+size_flags_horizontal = 3
+placeholder_text = "Type a message in world chat..."
+
+[node name="SendButton" type="Button" parent="VBoxContainer/TabContainer/WorldChat/SendHBox"]
+custom_minimum_size = Vector2(100, 36)
+layout_mode = 2
+text = "Send"
+
+[node name="DirectMessages" type="VBoxContainer" parent="VBoxContainer/TabContainer"]
+visible = false
+layout_mode = 2
+theme_override_constants/separation = 8
+metadata/_tab_index = 1
+
+[node name="StartHBox" type="HBoxContainer" parent="VBoxContainer/TabContainer/DirectMessages"]
+layout_mode = 2
+theme_override_constants/separation = 8
+
+[node name="TargetUserEdit" type="LineEdit" parent="VBoxContainer/TabContainer/DirectMessages/StartHBox"]
+layout_mode = 2
+size_flags_horizontal = 3
+placeholder_text = "Enter User ID to start conversation..."
+
+[node name="StartDmButton" type="Button" parent="VBoxContainer/TabContainer/DirectMessages/StartHBox"]
+custom_minimum_size = Vector2(140, 32)
+layout_mode = 2
+text = "Start Direct Chat"
+
+[node name="HSplit" type="HSplitContainer" parent="VBoxContainer/TabContainer/DirectMessages"]
+layout_mode = 2
+size_flags_vertical = 3
+split_offset = 260
+
+[node name="ConversationsVBox" type="VBoxContainer" parent="VBoxContainer/TabContainer/DirectMessages/HSplit"]
+layout_mode = 2
+size_flags_horizontal = 3
+size_flags_stretch_ratio = 0.35
+theme_override_constants/separation = 6
+
+[node name="ConvHeader" type="Label" parent="VBoxContainer/TabContainer/DirectMessages/HSplit/ConversationsVBox"]
+layout_mode = 2
+theme_override_font_sizes/font_size = 18
+text = "Conversations"
+
+[node name="Scroll" type="ScrollContainer" parent="VBoxContainer/TabContainer/DirectMessages/HSplit/ConversationsVBox"]
+layout_mode = 2
+size_flags_vertical = 3
+
+[node name="ConvList" type="VBoxContainer" parent="VBoxContainer/TabContainer/DirectMessages/HSplit/ConversationsVBox/Scroll"]
+layout_mode = 2
+size_flags_horizontal = 3
+theme_override_constants/separation = 4
+
+[node name="ChatVBox" type="VBoxContainer" parent="VBoxContainer/TabContainer/DirectMessages/HSplit"]
+layout_mode = 2
+size_flags_horizontal = 3
+theme_override_constants/separation = 6
+
+[node name="DmHeaderLabel" type="Label" parent="VBoxContainer/TabContainer/DirectMessages/HSplit/ChatVBox"]
+layout_mode = 2
+theme_override_font_sizes/font_size = 18
+text = "Select a conversation"
+
+[node name="Scroll" type="ScrollContainer" parent="VBoxContainer/TabContainer/DirectMessages/HSplit/ChatVBox"]
+layout_mode = 2
+size_flags_vertical = 3
+
+[node name="MessagesList" type="VBoxContainer" parent="VBoxContainer/TabContainer/DirectMessages/HSplit/ChatVBox/Scroll"]
+layout_mode = 2
+size_flags_horizontal = 3
+theme_override_constants/separation = 8
+
+[node name="SendHBox" type="HBoxContainer" parent="VBoxContainer/TabContainer/DirectMessages/HSplit/ChatVBox"]
+layout_mode = 2
+theme_override_constants/separation = 8
+
+[node name="MessageInput" type="LineEdit" parent="VBoxContainer/TabContainer/DirectMessages/HSplit/ChatVBox/SendHBox"]
+layout_mode = 2
+size_flags_horizontal = 3
+placeholder_text = "Type a direct message..."
+
+[node name="SendButton" type="Button" parent="VBoxContainer/TabContainer/DirectMessages/HSplit/ChatVBox/SendHBox"]
+custom_minimum_size = Vector2(100, 36)
+layout_mode = 2
+text = "Send"
+
+[node name="ReportDialog" type="ConfirmationDialog" parent="."]
+title = "Report Inappropriate Message"
+size = Vector2i(420, 200)
+
+[node name="VBox" type="VBoxContainer" parent="ReportDialog"]
+offset_left = 8.0
+offset_top = 8.0
+offset_right = 412.0
+offset_bottom = 151.0
+theme_override_constants/separation = 8
+
+[node name="DetailsLabel" type="Label" parent="ReportDialog/VBox"]
+layout_mode = 2
+autowrap_mode = 2
+
+[node name="ReasonPrompt" type="Label" parent="ReportDialog/VBox"]
+layout_mode = 2
+text = "Reason for report:"
+
+[node name="ReasonEdit" type="LineEdit" parent="ReportDialog/VBox"]
+layout_mode = 2
+text = "Inappropriate content"

scenes/friends_presence_ui.tscn

@@ -0,0 +1,174 @@
+[gd_scene load_steps=2 format=3]
+
+[ext_resource type="Script" path="res://scripts/friends_presence_ui.gd" id="1_fp"]
+
+[node name="FriendsPresenceUI" type="Control"]
+layout_mode = 3
+anchors_preset = 15
+anchor_right = 1.0
+anchor_bottom = 1.0
+grow_horizontal = 2
+grow_vertical = 2
+script = ExtResource("1_fp")
+
+[node name="VBoxContainer" type="VBoxContainer" parent="."]
+layout_mode = 1
+anchors_preset = 15
+anchor_right = 1.0
+anchor_bottom = 1.0
+offset_left = 32.0
+offset_top = 32.0
+offset_right = -32.0
+offset_bottom = -32.0
+grow_horizontal = 2
+grow_vertical = 2
+theme_override_constants/separation = 12
+
+[node name="HeaderHBox" type="HBoxContainer" parent="VBoxContainer"]
+layout_mode = 2
+theme_override_constants/separation = 16
+
+[node name="BackButton" type="Button" parent="VBoxContainer/HeaderHBox"]
+custom_minimum_size = Vector2(100, 36)
+layout_mode = 2
+text = "< Back"
+
+[node name="TitleLabel" type="Label" parent="VBoxContainer/HeaderHBox"]
+layout_mode = 2
+size_flags_horizontal = 3
+theme_override_font_sizes/font_size = 26
+text = "Friends & Social"
+horizontal_alignment = 1
+
+[node name="RefreshButton" type="Button" parent="VBoxContainer/HeaderHBox"]
+custom_minimum_size = Vector2(100, 36)
+layout_mode = 2
+text = "Refresh"
+
+[node name="MyStatusHBox" type="HBoxContainer" parent="VBoxContainer"]
+layout_mode = 2
+theme_override_constants/separation = 8
+
+[node name="StatusPrefix" type="Label" parent="VBoxContainer/MyStatusHBox"]
+layout_mode = 2
+text = "My Status:"
+
+[node name="StatusLineEdit" type="LineEdit" parent="VBoxContainer/MyStatusHBox"]
+layout_mode = 2
+size_flags_horizontal = 3
+placeholder_text = "What are you doing? (e.g. Exploring worlds...)"
+
+[node name="SetStatusButton" type="Button" parent="VBoxContainer/MyStatusHBox"]
+custom_minimum_size = Vector2(110, 32)
+layout_mode = 2
+text = "Set Status"
+
+[node name="StatusMessageLabel" type="Label" parent="VBoxContainer"]
+layout_mode = 2
+horizontal_alignment = 1
+
+[node name="TabContainer" type="TabContainer" parent="VBoxContainer"]
+layout_mode = 2
+size_flags_vertical = 3
+current_tab = 0
+
+[node name="Friends" type="VBoxContainer" parent="VBoxContainer/TabContainer"]
+layout_mode = 2
+theme_override_constants/separation = 8
+metadata/_tab_index = 0
+
+[node name="Scroll" type="ScrollContainer" parent="VBoxContainer/TabContainer/Friends"]
+layout_mode = 2
+size_flags_vertical = 3
+
+[node name="FriendsList" type="VBoxContainer" parent="VBoxContainer/TabContainer/Friends/Scroll"]
+layout_mode = 2
+size_flags_horizontal = 3
+theme_override_constants/separation = 8
+
+[node name="Requests" type="VBoxContainer" parent="VBoxContainer/TabContainer"]
+visible = false
+layout_mode = 2
+theme_override_constants/separation = 8
+metadata/_tab_index = 1
+
+[node name="SendHBox" type="HBoxContainer" parent="VBoxContainer/TabContainer/Requests"]
+layout_mode = 2
+theme_override_constants/separation = 8
+
+[node name="TargetUserIdEdit" type="LineEdit" parent="VBoxContainer/TabContainer/Requests/SendHBox"]
+layout_mode = 2
+size_flags_horizontal = 3
+placeholder_text = "Enter User ID to add..."
+
+[node name="SendButton" type="Button" parent="VBoxContainer/TabContainer/Requests/SendHBox"]
+custom_minimum_size = Vector2(120, 32)
+layout_mode = 2
+text = "Send Request"
+
+[node name="Scroll" type="ScrollContainer" parent="VBoxContainer/TabContainer/Requests"]
+layout_mode = 2
+size_flags_vertical = 3
+
+[node name="RequestsList" type="VBoxContainer" parent="VBoxContainer/TabContainer/Requests/Scroll"]
+layout_mode = 2
+size_flags_horizontal = 3
+theme_override_constants/separation = 8
+
+[node name="Following" type="VBoxContainer" parent="VBoxContainer/TabContainer"]
+visible = false
+layout_mode = 2
+theme_override_constants/separation = 8
+metadata/_tab_index = 2
+
+[node name="FollowHBox" type="HBoxContainer" parent="VBoxContainer/TabContainer/Following"]
+layout_mode = 2
+theme_override_constants/separation = 8
+
+[node name="FollowUserIdEdit" type="LineEdit" parent="VBoxContainer/TabContainer/Following/FollowHBox"]
+layout_mode = 2
+size_flags_horizontal = 3
+placeholder_text = "Enter User ID to follow..."
+
+[node name="FollowButton" type="Button" parent="VBoxContainer/TabContainer/Following/FollowHBox"]
+custom_minimum_size = Vector2(100, 32)
+layout_mode = 2
+text = "Follow"
+
+[node name="Scroll" type="ScrollContainer" parent="VBoxContainer/TabContainer/Following"]
+layout_mode = 2
+size_flags_vertical = 3
+
+[node name="FollowingList" type="VBoxContainer" parent="VBoxContainer/TabContainer/Following/Scroll"]
+layout_mode = 2
+size_flags_horizontal = 3
+theme_override_constants/separation = 8
+
+[node name="Blocked" type="VBoxContainer" parent="VBoxContainer/TabContainer"]
+visible = false
+layout_mode = 2
+theme_override_constants/separation = 8
+metadata/_tab_index = 3
+
+[node name="BlockHBox" type="HBoxContainer" parent="VBoxContainer/TabContainer/Blocked"]
+layout_mode = 2
+theme_override_constants/separation = 8
+
+[node name="BlockUserIdEdit" type="LineEdit" parent="VBoxContainer/TabContainer/Blocked/BlockHBox"]
+layout_mode = 2
+size_flags_horizontal = 3
+placeholder_text = "Enter User ID to block..."
+
+[node name="BlockButton" type="Button" parent="VBoxContainer/TabContainer/Blocked/BlockHBox"]
+custom_minimum_size = Vector2(100, 32)
+layout_mode = 2
+text = "Block"
+
+[node name="Scroll" type="ScrollContainer" parent="VBoxContainer/TabContainer/Blocked"]
+layout_mode = 2
+size_flags_vertical = 3
+
+[node name="BlockedList" type="VBoxContainer" parent="VBoxContainer/TabContainer/Blocked/Scroll"]
+layout_mode = 2
+size_flags_horizontal = 3
+theme_override_constants/separation = 8

scenes/groups_ui.tscn

@@ -0,0 +1,179 @@
+[gd_scene load_steps=2 format=3]
+
+[ext_resource type="Script" path="res://scripts/groups_ui.gd" id="1_gu"]
+
+[node name="GroupsUI" type="Control"]
+layout_mode = 3
+anchors_preset = 15
+anchor_right = 1.0
+anchor_bottom = 1.0
+grow_horizontal = 2
+grow_vertical = 2
+script = ExtResource("1_gu")
+
+[node name="VBoxContainer" type="VBoxContainer" parent="."]
+layout_mode = 1
+anchors_preset = 15
+anchor_right = 1.0
+anchor_bottom = 1.0
+offset_left = 32.0
+offset_top = 32.0
+offset_right = -32.0
+offset_bottom = -32.0
+grow_horizontal = 2
+grow_vertical = 2
+theme_override_constants/separation = 12
+
+[node name="HeaderHBox" type="HBoxContainer" parent="VBoxContainer"]
+layout_mode = 2
+theme_override_constants/separation = 16
+
+[node name="BackButton" type="Button" parent="VBoxContainer/HeaderHBox"]
+custom_minimum_size = Vector2(100, 36)
+layout_mode = 2
+text = "< Back"
+
+[node name="TitleLabel" type="Label" parent="VBoxContainer/HeaderHBox"]
+layout_mode = 2
+size_flags_horizontal = 3
+theme_override_font_sizes/font_size = 26
+text = "Groups & Communities"
+horizontal_alignment = 1
+
+[node name="RefreshButton" type="Button" parent="VBoxContainer/HeaderHBox"]
+custom_minimum_size = Vector2(100, 36)
+layout_mode = 2
+text = "Refresh"
+
+[node name="StatusMessageLabel" type="Label" parent="VBoxContainer"]
+layout_mode = 2
+horizontal_alignment = 1
+
+[node name="TabContainer" type="TabContainer" parent="VBoxContainer"]
+layout_mode = 2
+size_flags_vertical = 3
+current_tab = 0
+
+[node name="Browse" type="VBoxContainer" parent="VBoxContainer/TabContainer"]
+layout_mode = 2
+theme_override_constants/separation = 8
+metadata/_tab_index = 0
+
+[node name="FilterHBox" type="HBoxContainer" parent="VBoxContainer/TabContainer/Browse"]
+layout_mode = 2
+theme_override_constants/separation = 8
+
+[node name="MyGroupsCheck" type="CheckBox" parent="VBoxContainer/TabContainer/Browse/FilterHBox"]
+layout_mode = 2
+text = "Show only my groups"
+
+[node name="Scroll" type="ScrollContainer" parent="VBoxContainer/TabContainer/Browse"]
+layout_mode = 2
+size_flags_vertical = 3
+
+[node name="GroupsList" type="VBoxContainer" parent="VBoxContainer/TabContainer/Browse/Scroll"]
+layout_mode = 2
+size_flags_horizontal = 3
+theme_override_constants/separation = 8
+
+[node name="Create" type="VBoxContainer" parent="VBoxContainer/TabContainer"]
+visible = false
+layout_mode = 2
+theme_override_constants/separation = 8
+metadata/_tab_index = 1
+
+[node name="FormVBox" type="VBoxContainer" parent="VBoxContainer/TabContainer/Create"]
+custom_minimum_size = Vector2(480, 0)
+layout_mode = 2
+size_flags_horizontal = 4
+theme_override_constants/separation = 12
+
+[node name="NamePrompt" type="Label" parent="VBoxContainer/TabContainer/Create/FormVBox"]
+layout_mode = 2
+text = "Group Name:"
+
+[node name="NameEdit" type="LineEdit" parent="VBoxContainer/TabContainer/Create/FormVBox"]
+layout_mode = 2
+placeholder_text = "Enter unique group name..."
+
+[node name="DescPrompt" type="Label" parent="VBoxContainer/TabContainer/Create/FormVBox"]
+layout_mode = 2
+text = "Group Description:"
+
+[node name="DescEdit" type="TextEdit" parent="VBoxContainer/TabContainer/Create/FormVBox"]
+custom_minimum_size = Vector2(0, 100)
+layout_mode = 2
+placeholder_text = "Describe the goals and community of your group..."
+
+[node name="CreateButton" type="Button" parent="VBoxContainer/TabContainer/Create/FormVBox"]
+custom_minimum_size = Vector2(160, 36)
+layout_mode = 2
+size_flags_horizontal = 4
+text = "Create Group"
+
+[node name="GroupDetails" type="VBoxContainer" parent="VBoxContainer/TabContainer"]
+visible = false
+layout_mode = 2
+theme_override_constants/separation = 8
+metadata/_tab_index = 2
+
+[node name="Scroll" type="ScrollContainer" parent="VBoxContainer/TabContainer/GroupDetails"]
+layout_mode = 2
+size_flags_vertical = 3
+
+[node name="DetailsVBox" type="VBoxContainer" parent="VBoxContainer/TabContainer/GroupDetails/Scroll"]
+layout_mode = 2
+size_flags_horizontal = 3
+theme_override_constants/separation = 16
+
+[node name="HeaderHBox" type="HBoxContainer" parent="VBoxContainer/TabContainer/GroupDetails/Scroll/DetailsVBox"]
+layout_mode = 2
+theme_override_constants/separation = 16
+
+[node name="GroupNameLabel" type="Label" parent="VBoxContainer/TabContainer/GroupDetails/Scroll/DetailsVBox/HeaderHBox"]
+layout_mode = 2
+size_flags_horizontal = 3
+theme_override_font_sizes/font_size = 24
+text = "Select a Group"
+
+[node name="MemberCountLabel" type="Label" parent="VBoxContainer/TabContainer/GroupDetails/Scroll/DetailsVBox/HeaderHBox"]
+layout_mode = 2
+theme_override_font_sizes/font_size = 18
+text = "0 Members"
+
+[node name="GroupDescLabel" type="Label" parent="VBoxContainer/TabContainer/GroupDetails/Scroll/DetailsVBox"]
+layout_mode = 2
+autowrap_mode = 2
+text = "No description."
+
+[node name="ActionsHBox" type="HBoxContainer" parent="VBoxContainer/TabContainer/GroupDetails/Scroll/DetailsVBox"]
+layout_mode = 2
+theme_override_constants/separation = 12
+
+[node name="JoinButton" type="Button" parent="VBoxContainer/TabContainer/GroupDetails/Scroll/DetailsVBox/ActionsHBox"]
+custom_minimum_size = Vector2(100, 36)
+layout_mode = 2
+text = "Join Group"
+
+[node name="LeaveButton" type="Button" parent="VBoxContainer/TabContainer/GroupDetails/Scroll/DetailsVBox/ActionsHBox"]
+custom_minimum_size = Vector2(100, 36)
+layout_mode = 2
+text = "Leave Group"
+
+[node name="DeleteButton" type="Button" parent="VBoxContainer/TabContainer/GroupDetails/Scroll/DetailsVBox/ActionsHBox"]
+custom_minimum_size = Vector2(110, 36)
+layout_mode = 2
+text = "Delete Group"
+
+[node name="MembersVBox" type="VBoxContainer" parent="VBoxContainer/TabContainer/GroupDetails/Scroll/DetailsVBox"]
+layout_mode = 2
+theme_override_constants/separation = 8
+
+[node name="MembersHeader" type="Label" parent="VBoxContainer/TabContainer/GroupDetails/Scroll/DetailsVBox/MembersVBox"]
+layout_mode = 2
+theme_override_font_sizes/font_size = 18
+text = "Members & Roles"
+
+[node name="MembersList" type="VBoxContainer" parent="VBoxContainer/TabContainer/GroupDetails/Scroll/DetailsVBox/MembersVBox"]
+layout_mode = 2
+theme_override_constants/separation = 6

scenes/player.tscn

@@ -1,6 +1,7 @@
-[gd_scene load_steps=4 format=3 uid="uid://player_scene_001"]
+[gd_scene load_steps=5 format=3 uid="uid://player_scene_001"]
 
 [ext_resource type="Script" path="res://scripts/player.gd" id="1_player"]
+[ext_resource type="Script" path="res://scripts/scripting/player_inventory.gd" id="2_inventory"]
 
 [sub_resource type="CapsuleMesh" id="CapsuleMesh1"]
 radius = 0.35
@@ -30,3 +31,6 @@ margin = 0.2
 
 [node name="Camera3D" type="Camera3D" parent="CameraPivot/SpringArm3D"]
 current = true
+
+[node name="Inventory" type="Node" parent="."]
+script = ExtResource("2_inventory")

scenes/profile_ui.tscn

@@ -0,0 +1,215 @@
+[gd_scene load_steps=2 format=3]
+
+[ext_resource type="Script" path="res://scripts/profile_ui.gd" id="1_pu"]
+
+[node name="ProfileUI" type="Control"]
+layout_mode = 3
+anchors_preset = 15
+anchor_right = 1.0
+anchor_bottom = 1.0
+grow_horizontal = 2
+grow_vertical = 2
+script = ExtResource("1_pu")
+
+[node name="VBoxContainer" type="VBoxContainer" parent="."]
+layout_mode = 1
+anchors_preset = 15
+anchor_right = 1.0
+anchor_bottom = 1.0
+offset_left = 32.0
+offset_top = 32.0
+offset_right = -32.0
+offset_bottom = -32.0
+grow_horizontal = 2
+grow_vertical = 2
+theme_override_constants/separation = 12
+
+[node name="HeaderHBox" type="HBoxContainer" parent="VBoxContainer"]
+layout_mode = 2
+theme_override_constants/separation = 16
+
+[node name="BackButton" type="Button" parent="VBoxContainer/HeaderHBox"]
+custom_minimum_size = Vector2(100, 36)
+layout_mode = 2
+text = "< Back"
+
+[node name="TitleLabel" type="Label" parent="VBoxContainer/HeaderHBox"]
+layout_mode = 2
+size_flags_horizontal = 3
+theme_override_font_sizes/font_size = 26
+text = "Profile"
+horizontal_alignment = 1
+
+[node name="RefreshButton" type="Button" parent="VBoxContainer/HeaderHBox"]
+custom_minimum_size = Vector2(100, 36)
+layout_mode = 2
+text = "Refresh"
+
+[node name="LookupHBox" type="HBoxContainer" parent="VBoxContainer"]
+layout_mode = 2
+theme_override_constants/separation = 8
+
+[node name="LookupPrefix" type="Label" parent="VBoxContainer/LookupHBox"]
+layout_mode = 2
+text = "Lookup User ID:"
+
+[node name="UserIdEdit" type="LineEdit" parent="VBoxContainer/LookupHBox"]
+custom_minimum_size = Vector2(120, 32)
+layout_mode = 2
+placeholder_text = "e.g. 2"
+
+[node name="ViewUserButton" type="Button" parent="VBoxContainer/LookupHBox"]
+custom_minimum_size = Vector2(100, 32)
+layout_mode = 2
+text = "View"
+
+[node name="Spacer" type="Control" parent="VBoxContainer/LookupHBox"]
+layout_mode = 2
+size_flags_horizontal = 3
+
+[node name="ViewMyProfileButton" type="Button" parent="VBoxContainer/LookupHBox"]
+custom_minimum_size = Vector2(140, 32)
+layout_mode = 2
+text = "My Own Profile"
+
+[node name="StatusMessageLabel" type="Label" parent="VBoxContainer"]
+layout_mode = 2
+horizontal_alignment = 1
+
+[node name="Scroll" type="ScrollContainer" parent="VBoxContainer"]
+layout_mode = 2
+size_flags_vertical = 3
+
+[node name="ContentVBox" type="VBoxContainer" parent="VBoxContainer/Scroll"]
+layout_mode = 2
+size_flags_horizontal = 3
+theme_override_constants/separation = 16
+
+[node name="CardPanel" type="PanelContainer" parent="VBoxContainer/Scroll/ContentVBox"]
+layout_mode = 2
+
+[node name="Margin" type="MarginContainer" parent="VBoxContainer/Scroll/ContentVBox/CardPanel"]
+layout_mode = 2
+theme_override_constants/margin_left = 16
+theme_override_constants/margin_top = 16
+theme_override_constants/margin_right = 16
+theme_override_constants/margin_bottom = 16
+
+[node name="HBox" type="HBoxContainer" parent="VBoxContainer/Scroll/ContentVBox/CardPanel/Margin"]
+layout_mode = 2
+theme_override_constants/separation = 20
+
+[node name="AvatarBox" type="VBoxContainer" parent="VBoxContainer/Scroll/ContentVBox/CardPanel/Margin/HBox"]
+custom_minimum_size = Vector2(120, 120)
+layout_mode = 2
+alignment = 1
+
+[node name="AvatarLabel" type="Label" parent="VBoxContainer/Scroll/ContentVBox/CardPanel/Margin/HBox/AvatarBox"]
+layout_mode = 2
+text = "Avatar"
+horizontal_alignment = 1
+
+[node name="DetailsVBox" type="VBoxContainer" parent="VBoxContainer/Scroll/ContentVBox/CardPanel/Margin/HBox"]
+layout_mode = 2
+size_flags_horizontal = 3
+theme_override_constants/separation = 6
+
+[node name="UsernameLabel" type="Label" parent="VBoxContainer/Scroll/ContentVBox/CardPanel/Margin/HBox/DetailsVBox"]
+layout_mode = 2
+theme_override_font_sizes/font_size = 22
+text = "Username"
+
+[node name="UserIdLabel" type="Label" parent="VBoxContainer/Scroll/ContentVBox/CardPanel/Margin/HBox/DetailsVBox"]
+layout_mode = 2
+text = "User ID: --"
+
+[node name="BioPrompt" type="Label" parent="VBoxContainer/Scroll/ContentVBox/CardPanel/Margin/HBox/DetailsVBox"]
+layout_mode = 2
+text = "Bio:"
+
+[node name="BioEdit" type="TextEdit" parent="VBoxContainer/Scroll/ContentVBox/CardPanel/Margin/HBox/DetailsVBox"]
+custom_minimum_size = Vector2(0, 80)
+layout_mode = 2
+placeholder_text = "Tell the world about yourself..."
+
+[node name="SaveBioButton" type="Button" parent="VBoxContainer/Scroll/ContentVBox/CardPanel/Margin/HBox/DetailsVBox"]
+custom_minimum_size = Vector2(100, 32)
+layout_mode = 2
+size_flags_horizontal = 0
+text = "Save Bio"
+
+[node name="PrivacyVBox" type="VBoxContainer" parent="VBoxContainer/Scroll/ContentVBox"]
+layout_mode = 2
+theme_override_constants/separation = 8
+
+[node name="PrivacyHeader" type="Label" parent="VBoxContainer/Scroll/ContentVBox/PrivacyVBox"]
+layout_mode = 2
+theme_override_font_sizes/font_size = 18
+text = "Privacy Settings"
+
+[node name="Grid" type="GridContainer" parent="VBoxContainer/Scroll/ContentVBox/PrivacyVBox"]
+layout_mode = 2
+columns = 2
+theme_override_constants/h_separation = 16
+theme_override_constants/v_separation = 8
+
+[node name="ProfileVisLabel" type="Label" parent="VBoxContainer/Scroll/ContentVBox/PrivacyVBox/Grid"]
+layout_mode = 2
+text = "Profile Visibility:"
+
+[node name="ProfileVisOption" type="OptionButton" parent="VBoxContainer/Scroll/ContentVBox/PrivacyVBox/Grid"]
+layout_mode = 2
+
+[node name="FriendsVisLabel" type="Label" parent="VBoxContainer/Scroll/ContentVBox/PrivacyVBox/Grid"]
+layout_mode = 2
+text = "Friends List Visibility:"
+
+[node name="FriendsVisOption" type="OptionButton" parent="VBoxContainer/Scroll/ContentVBox/PrivacyVBox/Grid"]
+layout_mode = 2
+
+[node name="FavoritesVisLabel" type="Label" parent="VBoxContainer/Scroll/ContentVBox/PrivacyVBox/Grid"]
+layout_mode = 2
+text = "Favorites Visibility:"
+
+[node name="FavoritesVisOption" type="OptionButton" parent="VBoxContainer/Scroll/ContentVBox/PrivacyVBox/Grid"]
+layout_mode = 2
+
+[node name="SavePrivacyButton" type="Button" parent="VBoxContainer/Scroll/ContentVBox/PrivacyVBox"]
+custom_minimum_size = Vector2(140, 32)
+layout_mode = 2
+size_flags_horizontal = 0
+text = "Save Privacy"
+
+[node name="FavoritesVBox" type="VBoxContainer" parent="VBoxContainer/Scroll/ContentVBox"]
+layout_mode = 2
+theme_override_constants/separation = 8
+
+[node name="FavHeader" type="Label" parent="VBoxContainer/Scroll/ContentVBox/FavoritesVBox"]
+layout_mode = 2
+theme_override_font_sizes/font_size = 18
+text = "Favorite Experiences"
+
+[node name="FavoritesStatusLabel" type="Label" parent="VBoxContainer/Scroll/ContentVBox/FavoritesVBox"]
+layout_mode = 2
+text = "No favorite experiences yet."
+
+[node name="FavoritesList" type="VBoxContainer" parent="VBoxContainer/Scroll/ContentVBox/FavoritesVBox"]
+layout_mode = 2
+theme_override_constants/separation = 4
+
+[node name="FriendsVBox" type="VBoxContainer" parent="VBoxContainer/Scroll/ContentVBox"]
+layout_mode = 2
+theme_override_constants/separation = 8
+
+[node name="FriendsHeader" type="Label" parent="VBoxContainer/Scroll/ContentVBox/FriendsVBox"]
+layout_mode = 2
+theme_override_font_sizes/font_size = 18
+text = "Friends"
+
+[node name="FriendsStatusLabel" type="Label" parent="VBoxContainer/Scroll/ContentVBox/FriendsVBox"]
+layout_mode = 2
+text = "No friends listed."
+
+[node name="FriendsList" type="VBoxContainer" parent="VBoxContainer/Scroll/ContentVBox/FriendsVBox"]
+layout_mode = 2
+theme_override_constants/separation = 4

scenes/worlds/test_level.tscn

@@ -1,4 +1,6 @@
-[gd_scene load_steps=1 format=3 uid="uid://c49a36fc7db_test_level"]
+[gd_scene load_steps=2 format=3 uid="uid://c49a36fc7db_test_level"]
+
+[ext_resource type="Script" path="res://scripts/scripting/script_interpreter.gd" id="1_scripted_chest"]
 
 [sub_resource type="BoxShape3D" id="BoxShape3D_ground"]
 size = Vector3(40, 1, 40)
@@ -44,6 +46,12 @@ radius = 0.5
 subdivisions_ring = 8
 subdivisions_height = 8
 
+[sub_resource type="BoxShape3D" id="BoxShape3D_chest"]
+size = Vector3(1, 0.8, 0.6)
+
+[sub_resource type="BoxMesh" id="BoxMesh_chest"]
+size = Vector3(1, 0.8, 0.6)
+
 [sub_resource type="Environment" id="WorldEnvironment_env"]
 background_mode = 1
 background_color = Color(0.45, 0.62, 0.82, 1)
@@ -109,6 +117,18 @@ shape = SubResource("SphereShape3D_prop5")
 [node name="MeshInstance3D" type="MeshInstance3D" parent="Props/Prop5_SmallSphere"]
 mesh = SubResource("SphereMesh_prop5")
 
+[node name="ScriptedChest" type="StaticBody3D" parent="."]
+position = Vector3(0, 1.0, 1.5)
+script = ExtResource("1_scripted_chest")
+behavior_path = "res://assets/scripting/behaviors/demo_chest.json"
+interact_radius = 2.5
+
+[node name="CollisionShape3D" type="CollisionShape3D" parent="ScriptedChest"]
+shape = SubResource("BoxShape3D_chest")
+
+[node name="MeshInstance3D" type="MeshInstance3D" parent="ScriptedChest"]
+mesh = SubResource("BoxMesh_chest")
+
 [node name="Sun" type="DirectionalLight3D" parent="."]
 rotation = Vector3(-0.95, -0.5, 0)
 light_energy = 1.3

scripts/api_client.gd

@@ -69,9 +69,22 @@ func clear_token() -> void:
 
 var _base_url: String = "http://127.0.0.1:8000"
 
+## Read-only access to the configured backend base URL (no trailing slash).
+## Lets other client-side code that needs to build its own request outside
+## the [method request] primitive -- e.g. [HttpChunkSource], which needs raw
+## response bytes and custom headers `request()`'s JSON-only contract can't
+## give it -- target the same backend without duplicating the env var /
+## ProjectSettings resolution logic in `_ready()`.
+var base_url: String:
+	get:
+		return _base_url
+
 ## Request timeout in seconds. 0 disables the timeout.
 var timeout_seconds: float = 10.0
 
+## Real-time WebSocket gateway client instance
+var ws: WsGatewayClient = null
+
 
 func _ready() -> void:
 	# Environment variable override (e.g. for headless smoke tests against a
@@ -86,6 +99,24 @@ func _ready() -> void:
 			"http://127.0.0.1:8000"
 		)).rstrip("/")
 
+	ws = WsGatewayClient.new()
+	ws.name = "WsGatewayClient"
+	add_child(ws)
+
+
+## Connect to the WebSocket gateway using the current base_url and stored token.
+func connect_ws_gateway(token: String = "") -> Error:
+	if ws == null:
+		return ERR_UNCONFIGURED
+	var tok := token if token != "" else _access_token
+	return ws.connect_gateway(_base_url, tok)
+
+
+## Disconnect from the WebSocket gateway.
+func disconnect_ws_gateway() -> void:
+	if ws != null:
+		ws.disconnect_gateway()
+
 
 # ---------------------------------------------------------------------------
 # Core request primitive
@@ -245,6 +276,184 @@ func save_avatar_loadout(loadout: Dictionary) -> Dictionary:
 	return await request(HTTPClient.METHOD_PUT, "/api/avatar/loadout", body, "application/json", true)
 
 
+# ---------------------------------------------------------------------------
+# Social Features: Friends, Follow & Block
+# ---------------------------------------------------------------------------
+
+## Send a friend request to target user_id.
+func send_friend_request(user_id: int) -> Dictionary:
+	return await SocialApiClient.send_friend_request(self, user_id)
+
+## Get pending incoming friend requests.
+func get_friend_requests() -> Dictionary:
+	return await SocialApiClient.get_friend_requests(self)
+
+## Accept an incoming friend request.
+func accept_friend_request(request_id: int) -> Dictionary:
+	return await SocialApiClient.accept_friend_request(self, request_id)
+
+## Decline an incoming friend request.
+func decline_friend_request(request_id: int) -> Dictionary:
+	return await SocialApiClient.decline_friend_request(self, request_id)
+
+## Remove an existing friend.
+func unfriend(user_id: int) -> Dictionary:
+	return await SocialApiClient.unfriend(self, user_id)
+
+## Get list of mutual friends.
+func get_friends() -> Dictionary:
+	return await SocialApiClient.get_friends(self)
+
+## Follow a user.
+func follow_user(user_id: int) -> Dictionary:
+	return await SocialApiClient.follow_user(self, user_id)
+
+## Unfollow a user.
+func unfollow_user(user_id: int) -> Dictionary:
+	return await SocialApiClient.unfollow_user(self, user_id)
+
+## Get list of users followed by current user.
+func get_following() -> Dictionary:
+	return await SocialApiClient.get_following(self)
+
+## Block a user.
+func block_user(user_id: int) -> Dictionary:
+	return await SocialApiClient.block_user(self, user_id)
+
+## Unblock a user.
+func unblock_user(user_id: int) -> Dictionary:
+	return await SocialApiClient.unblock_user(self, user_id)
+
+## Get list of blocked users.
+func get_blocked() -> Dictionary:
+	return await SocialApiClient.get_blocked(self)
+
+
+# ---------------------------------------------------------------------------
+# Social Features: Presence
+# ---------------------------------------------------------------------------
+
+## Send presence heartbeat with optional custom status.
+func send_presence_heartbeat(custom_status: String = "") -> Dictionary:
+	return await SocialApiClient.send_presence_heartbeat(self, custom_status)
+
+## Get presence status of mutual friends.
+func get_friends_presence() -> Dictionary:
+	return await SocialApiClient.get_friends_presence(self)
+
+## Get presence status of a specific user.
+func get_user_presence(user_id: int) -> Dictionary:
+	return await SocialApiClient.get_user_presence(self, user_id)
+
+
+# ---------------------------------------------------------------------------
+# Social Features: Profiles
+# ---------------------------------------------------------------------------
+
+## Get current user's own profile.
+func get_my_profile() -> Dictionary:
+	return await SocialApiClient.get_my_profile(self)
+
+## Update current user's bio, avatar asset, or privacy settings.
+func update_my_profile(bio: Variant = null, avatar_asset_id: Variant = null, privacy: Variant = null) -> Dictionary:
+	return await SocialApiClient.update_my_profile(self, bio, avatar_asset_id, privacy)
+
+## Get current user's favorited world IDs.
+func get_my_favorites() -> Dictionary:
+	return await SocialApiClient.get_my_favorites(self)
+
+## Replace current user's favorited world IDs.
+func replace_my_favorites(world_ids: Array) -> Dictionary:
+	return await SocialApiClient.replace_my_favorites(self, world_ids)
+
+## Get public profile of another user.
+func get_public_profile(user_id: int) -> Dictionary:
+	return await SocialApiClient.get_public_profile(self, user_id)
+
+
+# ---------------------------------------------------------------------------
+# Social Features: Groups
+# ---------------------------------------------------------------------------
+
+## Create a new group.
+func create_group(name: String, description: String = "") -> Dictionary:
+	return await SocialApiClient.create_group(self, name, description)
+
+## List groups.
+func list_groups(page: int = 1, page_size: int = 50, mine: bool = false) -> Dictionary:
+	return await SocialApiClient.list_groups(self, page, page_size, mine)
+
+## Get group details and member list.
+func get_group(group_id: int) -> Dictionary:
+	return await SocialApiClient.get_group(self, group_id)
+
+## Update group name or description.
+func update_group(group_id: int, name: Variant = null, description: Variant = null) -> Dictionary:
+	return await SocialApiClient.update_group(self, group_id, name, description)
+
+## Delete a group (owner only).
+func delete_group(group_id: int) -> Dictionary:
+	return await SocialApiClient.delete_group(self, group_id)
+
+## Join a group.
+func join_group(group_id: int) -> Dictionary:
+	return await SocialApiClient.join_group(self, group_id)
+
+## Leave a group.
+func leave_group(group_id: int) -> Dictionary:
+	return await SocialApiClient.leave_group(self, group_id)
+
+## Set a member's role in a group.
+func set_group_member_role(group_id: int, user_id: int, role: String) -> Dictionary:
+	return await SocialApiClient.set_group_member_role(self, group_id, user_id, role)
+
+## Transfer ownership of a group.
+func transfer_group_ownership(group_id: int, new_owner_id: int) -> Dictionary:
+	return await SocialApiClient.transfer_group_ownership(self, group_id, new_owner_id)
+
+
+# ---------------------------------------------------------------------------
+# Social Features: Chat & Moderation
+# ---------------------------------------------------------------------------
+
+## List DM conversations for the authenticated user.
+func get_dm_conversations() -> Dictionary:
+	return await SocialApiClient.get_dm_conversations(self)
+
+## Start or get existing DM conversation with target user.
+func start_dm_conversation(target_user_id: int) -> Dictionary:
+	return await SocialApiClient.start_dm_conversation(self, target_user_id)
+
+## Get DM messages for a conversation.
+func get_dm_messages(conversation_id: int, before_id: int = 0, limit: int = 50) -> Dictionary:
+	return await SocialApiClient.get_dm_messages(self, conversation_id, before_id, limit)
+
+## Send a DM message to a conversation.
+func send_dm_message(conversation_id: int, content: String) -> Dictionary:
+	return await SocialApiClient.send_dm_message(self, conversation_id, content)
+
+## Get messages in world chat.
+func get_world_chat_messages(world_id: int, before_id: int = 0, limit: int = 50) -> Dictionary:
+	return await SocialApiClient.get_world_chat_messages(self, world_id, before_id, limit)
+
+## Send a message to world chat.
+func send_world_chat_message(world_id: int, content: String) -> Dictionary:
+	return await SocialApiClient.send_world_chat_message(self, world_id, content)
+
+## Get messages in room chat.
+func get_room_chat_messages(room_id: String, before_id: int = 0, limit: int = 50) -> Dictionary:
+	return await SocialApiClient.get_room_chat_messages(self, room_id, before_id, limit)
+
+## Send a message to room chat.
+func send_room_chat_message(room_id: String, content: String) -> Dictionary:
+	return await SocialApiClient.send_room_chat_message(self, room_id, content)
+
+## Report a message to the moderation queue.
+func report_message(message_id: int, conversation_type: String, reason: String, context_text: String = "") -> Dictionary:
+	return await SocialApiClient.report_message(self, message_id, conversation_type, reason, context_text)
+
+
+
 # ---------------------------------------------------------------------------
 # Internals
 # ---------------------------------------------------------------------------

scripts/chat_ui.gd

@@ -0,0 +1,330 @@
+extends Control
+class_name ChatUI
+## Chat UI for Direct Messages, World/Room Chat, and Message Reporting.
+##
+## Features:
+## - DM Conversations list + message thread
+## - In-experience World/Room chat thread
+## - Real-time WebSocket event dispatch for new messages
+## - Inline "Report" button on each message with reporting popup
+## - Rate limiting and error feedback display
+
+signal back_requested
+
+@onready var back_button: Button = $VBoxContainer/HeaderHBox/BackButton
+@onready var title_label: Label = $VBoxContainer/HeaderHBox/TitleLabel
+@onready var refresh_button: Button = $VBoxContainer/HeaderHBox/RefreshButton
+@onready var status_label: Label = $VBoxContainer/StatusMessageLabel
+
+@onready var tab_container: TabContainer = $VBoxContainer/TabContainer
+
+# World chat controls
+@onready var world_id_edit: LineEdit = $VBoxContainer/TabContainer/WorldChat/ControlsHBox/WorldIdEdit
+@onready var join_world_chat_btn: Button = $VBoxContainer/TabContainer/WorldChat/ControlsHBox/JoinChatButton
+@onready var world_messages_container: VBoxContainer = $VBoxContainer/TabContainer/WorldChat/Scroll/MessagesList
+@onready var world_msg_input: LineEdit = $VBoxContainer/TabContainer/WorldChat/SendHBox/MessageInput
+@onready var world_send_btn: Button = $VBoxContainer/TabContainer/WorldChat/SendHBox/SendButton
+
+# DM controls
+@onready var target_user_edit: LineEdit = $VBoxContainer/TabContainer/DirectMessages/StartHBox/TargetUserEdit
+@onready var start_dm_btn: Button = $VBoxContainer/TabContainer/DirectMessages/StartHBox/StartDmButton
+@onready var conv_list_container: VBoxContainer = $VBoxContainer/TabContainer/DirectMessages/HSplit/ConversationsVBox/Scroll/ConvList
+@onready var dm_header_label: Label = $VBoxContainer/TabContainer/DirectMessages/HSplit/ChatVBox/DmHeaderLabel
+@onready var dm_messages_container: VBoxContainer = $VBoxContainer/TabContainer/DirectMessages/HSplit/ChatVBox/Scroll/MessagesList
+@onready var dm_msg_input: LineEdit = $VBoxContainer/TabContainer/DirectMessages/HSplit/ChatVBox/SendHBox/MessageInput
+@onready var dm_send_btn: Button = $VBoxContainer/TabContainer/DirectMessages/HSplit/ChatVBox/SendHBox/SendButton
+
+# Report Popup
+@onready var report_dialog: ConfirmationDialog = $ReportDialog
+@onready var report_reason_edit: LineEdit = $ReportDialog/VBox/ReasonEdit
+@onready var report_details_label: Label = $ReportDialog/VBox/DetailsLabel
+
+var _api_client: Node = null
+var _current_world_id: int = 1
+var _active_conversation_id: int = 0
+var _reporting_message_id: int = 0
+var _reporting_conv_type: String = ""
+var _reporting_context: String = ""
+
+
+func _ready() -> void:
+	_api_client = _get_api()
+	_wire_signals()
+	if _api_client != null and _api_client.has_token():
+		refresh_world_chat()
+		refresh_dm_conversations()
+
+
+func _get_api() -> Node:
+	if has_node("/root/ApiClient"):
+		return get_node("/root/ApiClient")
+	return null
+
+
+func _wire_signals() -> void:
+	if back_button:
+		back_button.pressed.connect(_on_back_pressed)
+	if refresh_button:
+		refresh_button.pressed.connect(refresh_active_tab)
+
+	# World chat
+	if join_world_chat_btn:
+		join_world_chat_btn.pressed.connect(_on_join_world_chat)
+	if world_send_btn:
+		world_send_btn.pressed.connect(_on_send_world_message)
+	if world_msg_input:
+		world_msg_input.text_submitted.connect(func(_t): _on_send_world_message())
+
+	# DM chat
+	if start_dm_btn:
+		start_dm_btn.pressed.connect(_on_start_dm_pressed)
+	if dm_send_btn:
+		dm_send_btn.pressed.connect(_on_send_dm_message)
+	if dm_msg_input:
+		dm_msg_input.text_submitted.connect(func(_t): _on_send_dm_message())
+
+	# Report dialog
+	if report_dialog:
+		report_dialog.confirmed.connect(_on_report_confirmed)
+
+	# WebSocket real-time hook
+	if _api_client != null and _api_client.ws != null:
+		if not _api_client.ws.chat_message_received.is_connected(_on_ws_chat_message):
+			_api_client.ws.chat_message_received.connect(_on_ws_chat_message)
+
+
+func _on_back_pressed() -> void:
+	back_requested.emit()
+	if get_tree().current_scene == self:
+		get_tree().change_scene_to_file("res://scenes/main_menu.tscn")
+
+
+func show_message(text: String, is_error: bool = false) -> void:
+	if status_label:
+		status_label.text = text
+		status_label.modulate = Color(1.0, 0.4, 0.4) if is_error else Color(0.4, 1.0, 0.4)
+
+
+func refresh_active_tab() -> void:
+	if tab_container == null:
+		return
+	if tab_container.current_tab == 0:
+		refresh_world_chat()
+	else:
+		refresh_dm_conversations()
+		if _active_conversation_id > 0:
+			refresh_dm_messages(_active_conversation_id)
+
+
+# ── World Chat ──
+
+func _on_join_world_chat() -> void:
+	var wid_str := world_id_edit.text.strip_edges()
+	if not wid_str.is_valid_int():
+		show_message("Enter a valid integer world ID.", true)
+		return
+	_current_world_id = int(wid_str)
+	if _api_client != null and _api_client.ws != null:
+		_api_client.ws.subscribe_world(_current_world_id)
+	show_message("Joined world %d chat." % _current_world_id)
+	refresh_world_chat()
+
+
+func refresh_world_chat() -> void:
+	if _api_client == null or not _api_client.has_token():
+		return
+	var res: Dictionary = await _api_client.get_world_chat_messages(_current_world_id)
+	_clear_children(world_messages_container)
+
+	if not res.ok:
+		show_message("Failed to load world chat: " + res.detail, true)
+		return
+
+	var msgs: Array = []
+	if res.data is Dictionary and res.data.has("messages"):
+		msgs = res.data["messages"]
+	elif res.data is Array:
+		msgs = res.data
+
+	for m in msgs:
+		_add_message_row(world_messages_container, m, "world")
+
+
+func _on_send_world_message() -> void:
+	var content := world_msg_input.text.strip_edges()
+	if content == "":
+		return
+	var res: Dictionary = await _api_client.send_world_chat_message(_current_world_id, content)
+	if res.ok:
+		world_msg_input.text = ""
+		refresh_world_chat()
+	else:
+		show_message("Send failed: " + res.detail, true)
+
+
+# ── Direct Messages (DMs) ──
+
+func refresh_dm_conversations() -> void:
+	if _api_client == null or not _api_client.has_token():
+		return
+	var res: Dictionary = await _api_client.get_dm_conversations()
+	_clear_children(conv_list_container)
+
+	if not res.ok:
+		show_message("Failed to load DMs: " + res.detail, true)
+		return
+
+	var convs: Array = []
+	if res.data is Dictionary and res.data.has("conversations"):
+		convs = res.data["conversations"]
+	elif res.data is Array:
+		convs = res.data
+
+	if convs.is_empty():
+		var empty_lbl := Label.new()
+		empty_lbl.text = "No conversations yet."
+		empty_lbl.modulate = Color(0.6, 0.6, 0.6)
+		conv_list_container.add_child(empty_lbl)
+		return
+
+	for c in convs:
+		var cid: int = int(c.get("id", 0))
+		var other_name: String = "Conversation #%d" % cid
+		if c.has("other_user") and c["other_user"] is Dictionary:
+			other_name = str(c["other_user"].get("username", other_name))
+
+		var btn := Button.new()
+		btn.text = other_name
+		btn.size_flags_horizontal = Control.SIZE_EXPAND_FILL
+		btn.pressed.connect(func(): _select_dm_conversation(cid, other_name))
+		conv_list_container.add_child(btn)
+
+
+func _select_dm_conversation(cid: int, name_hint: String) -> void:
+	_active_conversation_id = cid
+	if dm_header_label:
+		dm_header_label.text = "Chat with " + name_hint
+	if _api_client != null and _api_client.ws != null:
+		_api_client.ws.subscribe_dm(cid)
+	refresh_dm_messages(cid)
+
+
+func refresh_dm_messages(cid: int) -> void:
+	if _api_client == null or cid <= 0:
+		return
+	var res: Dictionary = await _api_client.get_dm_messages(cid)
+	_clear_children(dm_messages_container)
+
+	if not res.ok:
+		show_message("Failed to load messages: " + res.detail, true)
+		return
+
+	var msgs: Array = []
+	if res.data is Dictionary and res.data.has("messages"):
+		msgs = res.data["messages"]
+	elif res.data is Array:
+		msgs = res.data
+
+	for m in msgs:
+		_add_message_row(dm_messages_container, m, "dm")
+
+
+func _on_start_dm_pressed() -> void:
+	var target_text := target_user_edit.text.strip_edges()
+	if not target_text.is_valid_int():
+		show_message("Enter a valid integer user ID.", true)
+		return
+	var target_id := int(target_text)
+	var res: Dictionary = await _api_client.start_dm_conversation(target_id)
+	if res.ok and res.data is Dictionary:
+		var cid: int = int(res.data.get("id", 0))
+		target_user_edit.text = ""
+		show_message("Conversation started!")
+		await refresh_dm_conversations()
+		_select_dm_conversation(cid, "User #%d" % target_id)
+	else:
+		show_message("Failed to start conversation: " + res.detail, true)
+
+
+func _on_send_dm_message() -> void:
+	if _active_conversation_id <= 0:
+		show_message("Select or start a conversation first.", true)
+		return
+	var content := dm_msg_input.text.strip_edges()
+	if content == "":
+		return
+	var res: Dictionary = await _api_client.send_dm_message(_active_conversation_id, content)
+	if res.ok:
+		dm_msg_input.text = ""
+		refresh_dm_messages(_active_conversation_id)
+	else:
+		show_message("Send failed: " + res.detail, true)
+
+
+# ── Message Row & Reporting ──
+
+func _add_message_row(container: VBoxContainer, msg_data: Dictionary, conv_type: String) -> void:
+	var hbox := HBoxContainer.new()
+	hbox.add_theme_constant_override("separation", 8)
+
+	var mid: int = int(msg_data.get("id", 0))
+	var author: String = "User #%s" % str(msg_data.get("author_id", msg_data.get("sender_id", "?")))
+	if msg_data.has("author") and msg_data["author"] is Dictionary:
+		author = str(msg_data["author"].get("username", author))
+	elif msg_data.has("sender") and msg_data["sender"] is Dictionary:
+		author = str(msg_data["sender"].get("username", author))
+
+	var content: String = str(msg_data.get("content", ""))
+
+	var label := Label.new()
+	label.text = "[%s]: %s" % [author, content]
+	label.size_flags_horizontal = Control.SIZE_EXPAND_FILL
+	label.autowrap_mode = TextServer.AUTOWRAP_WORD_SMART
+	hbox.add_child(label)
+
+	var report_btn := Button.new()
+	report_btn.text = "Report"
+	report_btn.pressed.connect(func(): _open_report_dialog(mid, conv_type, content))
+	hbox.add_child(report_btn)
+
+	container.add_child(hbox)
+
+
+func _open_report_dialog(msg_id: int, conv_type: String, context_text: String) -> void:
+	_reporting_message_id = msg_id
+	_reporting_conv_type = conv_type
+	_reporting_context = context_text
+
+	if report_details_label:
+		report_details_label.text = "Reporting message: \"%s\"" % context_text.left(60)
+	if report_reason_edit:
+		report_reason_edit.text = "Inappropriate content"
+	if report_dialog:
+		report_dialog.popup_centered()
+
+
+func _on_report_confirmed() -> void:
+	if _reporting_message_id <= 0 or _api_client == null:
+		return
+	var reason := report_reason_edit.text.strip_edges() if report_reason_edit else "Inappropriate content"
+	var res: Dictionary = await _api_client.report_message(_reporting_message_id, _reporting_conv_type, reason, _reporting_context)
+	if res.ok:
+		show_message("Message reported to moderation queue. Thank you!")
+	else:
+		show_message("Failed to report message: " + res.detail, true)
+
+
+# ── Real-Time WS Hook ──
+
+func _on_ws_chat_message(channel: String, id: int, data: Dictionary) -> void:
+	if channel == "world" and id == _current_world_id:
+		_add_message_row(world_messages_container, data, "world")
+	elif channel == "dm" and id == _active_conversation_id:
+		_add_message_row(dm_messages_container, data, "dm")
+
+
+func _clear_children(node: Node) -> void:
+	if node == null:
+		return
+	for c in node.get_children():
+		c.queue_free()

scripts/chunk_data_decoder.gd

@@ -100,6 +100,17 @@ class TileLayerData:
 			return tiles[idx]
 		return 0
 
+	## Editor mutator: writes `tile_id` at (x, y, z). Silently no-ops out of
+	## bounds, mirroring get_tile's "out of bounds is empty" contract rather
+	## than erroring -- callers that need bounds feedback should check first
+	## (see ChunkEditorModel.is_tile_in_bounds in scripts/editor/).
+	func set_tile(x: int, y: int, z: int, tile_id: int) -> void:
+		if x < 0 or x >= width or y < 0 or y >= height or z < 0 or z >= depth:
+			return
+		var idx := (z * height + y) * width + x
+		if idx < tiles.size():
+			tiles[idx] = tile_id
+
 	func get_tile_def(tile_id: int) -> TileDef:
 		for def in palette:
 			if def.id == tile_id:
@@ -404,7 +415,15 @@ static func _parse_object_section(data: PackedByteArray, result: ChunkPayload) -
 	offset += 2
 	var props_str := data.slice(offset, offset + props_len).get_string_from_utf8()
 	offset += props_len
-	obj.properties = JSON.parse_string(props_str) or {}
+	# `or` in GDScript is a boolean operator, not Python/JS-style
+	# short-circuit-return -- `parsed or {}` returns a bool (true for any
+	# non-empty Dictionary), not `parsed` itself. Assigning that bool to
+	# `properties` (typed Dictionary) crashes at runtime for any object
+	# with real property data -- verified: a real fixture with
+	# {"locked": false, ...} threw "Invalid assignment of property or key
+	# 'properties' with value of type 'bool'".
+	var parsed_props: Variant = JSON.parse_string(props_str)
+	obj.properties = parsed_props if parsed_props is Dictionary else {}
 
 	# flags (ContentFlags)
 	obj.flags.violence = data[offset]
@@ -484,13 +503,33 @@ static func _build_metadata_section(payload: ChunkPayload) -> PackedByteArray:
 	data.append_array(_write_int32(payload.coord.x))
 	data.append_array(_write_int32(payload.coord.y))
 	data.append_array(_write_int32(payload.coord.z))
+	# Wire format is min + max (world.md §3, and _parse_metadata_section
+	# below reads the 2nd triple as max_pos and computes size = max - min)
+	# -- writing raw `.size` here instead of `.position + .size` was a
+	# latent bug that only escaped every test because AABB(Vector3.ZERO, ...)
+	# happens to make size == max when position is exactly zero. Any chunk
+	# at a real, nonzero world position (i.e. every real chunk except the
+	# one at the origin) would round-trip through encode_binary/decode_binary
+	# with a corrupted size. Same bug class as the backend's min+size/
+	# min+max mismatch fixed in chunk_codec.py (commit eb39e43).
+	var bounds_max: Vector3 = payload.bounds.position + payload.bounds.size
 	data.append_array(_write_float32(payload.bounds.position.x))
 	data.append_array(_write_float32(payload.bounds.position.y))
 	data.append_array(_write_float32(payload.bounds.position.z))
-	data.append_array(_write_float32(payload.bounds.size.x))
+	data.append_array(_write_float32(bounds_max.x))
-	data.append_array(_write_float32(payload.bounds.size.y))
+	data.append_array(_write_float32(bounds_max.y))
-	data.append_array(_write_float32(payload.bounds.size.z))
+	data.append_array(_write_float32(bounds_max.z))
-	return data
+	# Every other section builder wraps its body with `_wrap_section`
+	# (section_id + uint32 length prefix) -- this one didn't, so
+	# `encode_binary()` spliced the raw metadata bytes directly into the
+	# section stream with no header at all. The decoder then read the
+	# metadata's own first bytes (a string length prefix) as a bogus
+	# section_id/section_len pair, producing a garbage length that
+	# overran the buffer ("truncated section body") and silently found
+	# zero real sections. Never caught before because nothing in this
+	# codebase called encode_binary() until
+	# scripts/smoke_test_http_chunk_source.gd.
+	return _wrap_section(data, SECTION_META)
 
 
 static func _build_tile_section(layer: TileLayerData) -> PackedByteArray:
@@ -607,8 +646,11 @@ static func _read_int64(data: PackedByteArray, offset: int) -> int:
 	return hi * 0x100000000 + lo
 
 static func _read_float32(data: PackedByteArray, offset: int) -> float:
-	var bits := _read_uint32(data, offset)
+	# `int as float` is a NUMERIC cast, not an IEEE-754 bit reinterpretation --
-	return bits as float  # GDScript float is 64-bit; bits repr works for IEEE 754
+	# it was silently corrupting every non-integer value (verified: bits for
+	# 1.5f decoded as 1069547520.0). decode_float() does a real bitcast and
+	# matches this format's little-endian byte order (§3.6).
+	return data.decode_float(offset)
 
 static func _read_hex_string(data: PackedByteArray, offset: int, length: int) -> String:
 	var hex_chars := "0123456789abcdef"
@@ -637,8 +679,10 @@ static func _write_int64(val: int) -> PackedByteArray:
 	return _write_uint32(lo) + _write_uint32(hi)
 
 static func _write_float32(val: float) -> PackedByteArray:
-	var bits := val as int
+	var out := PackedByteArray()
-	return _write_uint32(bits)
+	out.resize(4)
+	out.encode_float(0, val)
+	return out
 
 static func _write_string(s: String) -> PackedByteArray:
 	var bytes := s.to_utf8_buffer()

scripts/chunk_stream_manager.gd

@@ -241,7 +241,11 @@ func _instantiate_chunk_scene_with_data(coord: Vector3i, data: ChunkDataDecoder.
 	chunk_scene.coord = coord
 	chunk_scene.key = data.key
 	chunk_scene.bounds = data.bounds
-	chunk_scene.format_version = data.format_version
+	# ChunkDataDecoder.ChunkPayload's field is named `version`, not
+	# `format_version` -- this was a hard crash ("Invalid access to
+	# property or key 'format_version'") the first time real decoded data
+	# ever reached this dormant method (via HttpChunkSource).
+	chunk_scene.format_version = data.version
 	chunk_scene.revision = data.revision
 
 	# Add tiles
@@ -348,7 +352,13 @@ func clear_all_chunks() -> void:
 
 func _parse_coord_from_key(key: String) -> Variant:
 	"""Parse chunk coordinate from a canonical chunk key."""
-	var parts: Array[String] = key.split(":")
+	# String.split() returns PackedStringArray, not Array[String] -- those
+	# are different container types with no implicit conversion, so this
+	# raised "Trying to assign a value of type 'PackedStringArray' to a
+	# variable of type 'Array[String]'" the moment real data reached this
+	# dormant method for the first time (via HttpChunkSource's
+	# _on_chunk_data_received call -- nothing exercised this path before).
+	var parts: PackedStringArray = key.split(":")
 	if parts.size() < 5:
 		return null
 	return Vector3i(

scripts/editor/chunk_editor_model.gd

@@ -0,0 +1,190 @@
+class_name ChunkEditorModel
+extends RefCounted
+## In-memory chunk being edited (docs/architecture/editor.md §7.1's
+## `ChunkEditorModel`).
+##
+## Wraps a `ChunkDataDecoder.ChunkPayload` directly rather than inventing a
+## parallel data model -- that payload is already the exact structure that
+## round-trips through `ChunkDataDecoder.encode_binary()` /
+## `decode_binary()` (world.md §3.6, and the interop bugs fixed in that file
+## are proof this contract is exercised for real). Editing this model and
+## re-encoding it must always produce a valid, byte-compatible chunk, since
+## the sibling save-path task depends on that being true.
+##
+## Every method here is a "raw" mutator: it changes the payload and returns
+## whatever an undo needs to reverse the change, but it does **not** know
+## about undo/redo itself. `scripts/editor/editor_core.gd`'s tools
+## (scripts/editor/tools/*.gd) are the only things that call these -- they
+## wrap each call in an `EditorUndoRedoStack` action. Nothing here should be
+## called directly by UI code; that would bypass undo/redo silently.
+
+var payload: ChunkDataDecoder.ChunkPayload
+
+## Monotonic counter seeded from the highest existing "obj_NNNN"-style
+## numeric suffix already in the chunk, so freshly generated ids never
+## collide with ids that arrived from a decoded chunk.
+var _next_object_seq: int = 0
+
+
+func _init(p_payload: ChunkDataDecoder.ChunkPayload = null) -> void:
+	payload = p_payload if p_payload != null else ChunkDataDecoder.ChunkPayload.new()
+	_seed_object_sequence()
+
+
+func _seed_object_sequence() -> void:
+	for obj in payload.objects:
+		var n := _numeric_suffix(obj.id)
+		if n >= _next_object_seq:
+			_next_object_seq = n + 1
+
+
+static func _numeric_suffix(id: String) -> int:
+	var digits := ""
+	for i in range(id.length() - 1, -1, -1):
+		var c: String = id[i]
+		if c.is_valid_int():
+			digits = c + digits
+		else:
+			break
+	return int(digits) if digits != "" else -1
+
+
+## Build a fresh, empty single-layer chunk model -- convenient for tests and
+## for a "new chunk" starting point in the in-game editor before a real
+## chunk has been loaded from the backend (loading real chunks over HTTP is
+## HttpChunkSource's job; this just gives the editor something valid to
+## operate on).
+static func create_empty(width: int = 32, height: int = 32, world_id: String = "",
+		room_id: String = "main", coord: Vector3i = Vector3i.ZERO) -> ChunkEditorModel:
+	var layer := ChunkDataDecoder.TileLayerData.new()
+	layer.name = "ground"
+	layer.layer_id = 0
+	layer.width = width
+	layer.height = height
+	layer.depth = 1
+	layer.palette = [
+		TileDef.new(0, "", false, 0, 1),
+		TileDef.new(1, "tiles/default", true, 0, 1),
+	]
+	var tiles := PackedInt32Array()
+	tiles.resize(width * height)
+	layer.tiles = tiles
+
+	var payload := ChunkDataDecoder.ChunkPayload.new()
+	payload.world_id = world_id
+	payload.room_id = room_id
+	payload.coord = coord
+	payload.bounds = AABB(Vector3(coord.x * width, coord.y * height, coord.z), Vector3(width, height, 1))
+	payload.tile_layers = [layer]
+	payload.revision = 0
+	payload.created_at = Time.get_unix_time_from_system()
+	payload.updated_at = payload.created_at
+	return ChunkEditorModel.new(payload)
+
+
+static func from_binary(data: PackedByteArray) -> ChunkEditorModel:
+	var decoded := ChunkDataDecoder.decode_binary(data)
+	if decoded == null:
+		return null
+	return ChunkEditorModel.new(decoded)
+
+
+func encode_binary() -> PackedByteArray:
+	return ChunkDataDecoder.encode_binary(payload)
+
+
+# ───────────────────────── tiles ─────────────────────────
+
+func get_layer(layer_idx: int) -> ChunkDataDecoder.TileLayerData:
+	if layer_idx < 0 or layer_idx >= payload.tile_layers.size():
+		return null
+	return payload.tile_layers[layer_idx]
+
+
+func is_tile_in_bounds(layer_idx: int, x: int, y: int, z: int = 0) -> bool:
+	var layer := get_layer(layer_idx)
+	if layer == null:
+		return false
+	return x >= 0 and x < layer.width and y >= 0 and y < layer.height and z >= 0 and z < layer.depth
+
+
+func get_tile_raw(layer_idx: int, x: int, y: int, z: int = 0) -> int:
+	var layer := get_layer(layer_idx)
+	if layer == null:
+		return 0
+	return layer.get_tile(x, y, z)
+
+
+## Raw setter -- undo-unaware. Only ever called (in both directions) by
+## BrushTool/EraseTool via EditorUndoRedoStack.
+func set_tile_raw(layer_idx: int, x: int, y: int, z: int, tile_id: int) -> void:
+	var layer := get_layer(layer_idx)
+	if layer == null:
+		return
+	layer.set_tile(x, y, z, tile_id)
+
+
+# ───────────────────────── objects ─────────────────────────
+
+func find_object(object_id: String) -> ChunkDataDecoder.WorldObjectData:
+	for obj in payload.objects:
+		if obj.id == object_id:
+			return obj
+	return null
+
+
+func get_object_index(object_id: String) -> int:
+	for i in range(payload.objects.size()):
+		if payload.objects[i].id == object_id:
+			return i
+	return -1
+
+
+func generate_object_id() -> String:
+	var id := "obj_%04d" % _next_object_seq
+	_next_object_seq += 1
+	return id
+
+
+## Raw mutators -- undo-unaware. Only ever called (in both directions) by
+## ObjectPlaceTool/EraseTool/TransformTool via EditorUndoRedoStack.
+func add_object_raw(obj: ChunkDataDecoder.WorldObjectData) -> void:
+	payload.objects.append(obj)
+
+
+func insert_object_raw(obj: ChunkDataDecoder.WorldObjectData, index: int) -> void:
+	var clamped: int = clampi(index, 0, payload.objects.size())
+	payload.objects.insert(clamped, obj)
+
+
+func remove_object_raw(object_id: String) -> ChunkDataDecoder.WorldObjectData:
+	var idx := get_object_index(object_id)
+	if idx == -1:
+		return null
+	var obj := payload.objects[idx]
+	payload.objects.remove_at(idx)
+	return obj
+
+
+func set_object_position_raw(object_id: String, position: Vector3) -> void:
+	var obj := find_object(object_id)
+	if obj != null:
+		obj.position = position
+
+
+func set_object_rotation_raw(object_id: String, rotation: Vector4) -> void:
+	var obj := find_object(object_id)
+	if obj != null:
+		obj.rotation = rotation
+
+
+func set_object_scale_raw(object_id: String, scale: Vector3) -> void:
+	var obj := find_object(object_id)
+	if obj != null:
+		obj.scale = scale
+
+
+func set_object_property_raw(object_id: String, key: String, value: Variant) -> void:
+	var obj := find_object(object_id)
+	if obj != null:
+		obj.properties[key] = value

scripts/editor/chunk_save_service.gd

@@ -0,0 +1,280 @@
+class_name ChunkSaveService
+extends Node
+## HTTP save path for the in-game editor
+## (docs/architecture/world_persistence_impl.md §8.1 chunk write / §8.2 D5).
+##
+## Owns the write half of editor persistence: single-chunk PUT with
+## `X-Base-Revision`/`base_revision`, batch PUT for a multi-chunk edit, and
+## the §5.4 optimistic-concurrency retry loop on `409`.
+##
+## Conflict handling ("re-fetch current chunk, re-apply the edit, retry"):
+## per §8.2 D5 this backend stores and accepts **whole chunks**, not
+## JSON-Patch deltas -- "lost-update protection comes from `base_revision`,
+## not from the patch". That means there is no delta to replay against a
+## freshly-fetched chunk; "re-apply the edit" is exactly "keep the locally
+## edited payload, learn the chunk's current revision, and retry at that
+## revision". `fetch_chunk()` is still called on a conflict (rather than
+## just trusting the 409 body's `current_revision`) so the editor's own
+## last-known state stays in sync with the store, matching what a real
+## client does before retrying a write it doesn't fully trust yet.
+##
+## Deliberately does **not** use `ApiClient.request()`: that helper discards
+## the parsed JSON body on any non-2xx response (see its `_make_result`
+## calls), and the `409` body's `current_revision`/`current_checksum` are
+## exactly what this retry loop needs. Uses a raw per-request `HTTPRequest`
+## child instead, the same pattern `scripts/http_chunk_source.gd` uses for
+## the read side.
+##
+## Must be added to the scene tree before use.
+
+## The world this service saves chunks for (string form of the backend's
+## numeric world id).
+var world_id: String = ""
+
+## The room slug within that world. world.md's default room is "main".
+var room_slug: String = "main"
+
+## Bounded retries on a 409 conflict -- refuses to loop forever against a
+## chunk under sustained contention.
+const MAX_RETRIES := 3
+
+
+## Fetch the current chunk at [param coord].
+##
+## Returns:
+##     {"ok": bool, "status": int, "model": ChunkEditorModel|null,
+##      "revision": int, "checksum": String, "detail": String}
+##
+## A `404` (unwritten coordinate) is reported as `ok: true, model: null` --
+## world_persistence_impl.md §8.1: "an unwritten coordinate is not an error".
+## Callers wanting a fresh chunk to edit should fall back to
+## `ChunkEditorModel.create_empty()` at `base_revision: 0` in that case.
+func fetch_chunk(coord: Vector3i) -> Dictionary:
+	var http := HTTPRequest.new()
+	http.timeout = 15.0
+	add_child(http)
+
+	var api := _api_client()
+	var headers := PackedStringArray(["Accept: application/octet-stream"])
+	if api.has_token():
+		headers.append("Authorization: " + str(api.bearer_token))
+
+	var url: String = str(api.base_url) + _chunk_path(coord)
+	var err := http.request(url, headers, HTTPClient.METHOD_GET)
+	if err != OK:
+		http.queue_free()
+		return _fetch_result(false, 0, null, 0, "", "request failed to start (%d)" % err)
+
+	var args: Array = await http.request_completed
+	var result_code: int = args[0]
+	var response_code: int = args[1]
+	var response_headers: PackedStringArray = args[2]
+	var body: PackedByteArray = args[3]
+	http.queue_free()
+
+	if result_code != HTTPRequest.RESULT_SUCCESS:
+		return _fetch_result(false, 0, null, 0, "", "transport error (%d)" % result_code)
+
+	if response_code == 404:
+		return _fetch_result(true, 404, null, 0, "", "not found (unwritten chunk)")
+
+	if response_code != 200:
+		return _fetch_result(false, response_code, null, 0, "", _error_detail_from_body(body))
+
+	var model := ChunkEditorModel.from_binary(body)
+	if model == null:
+		return _fetch_result(false, response_code, null, 0, "", "failed to decode chunk payload")
+
+	return _fetch_result(
+		true, 200, model,
+		_int_header(response_headers, "x-chunk-revision"),
+		_etag_from_headers(response_headers),
+		"OK",
+	)
+
+
+## Save one chunk. `model.encode_binary()` is sent as the new payload;
+## `base_revision` is the revision the editor last knew about (0 = create).
+##
+## Returns:
+##     {"ok": bool, "status": int, "revision": int, "checksum": String,
+##      "live_session": bool, "retried": bool, "detail": String}
+func save_chunk(model: ChunkEditorModel, coord: Vector3i, base_revision: int) -> Dictionary:
+	var attempt_revision := base_revision
+	var retried := false
+	for attempt in range(MAX_RETRIES + 1):
+		var body := {
+			"base_revision": attempt_revision,
+			"payload_b64": Marshalls.raw_to_base64(model.encode_binary()),
+		}
+		var resp := await _request_json(HTTPClient.METHOD_PUT, _chunk_path(coord), body)
+
+		if resp["status"] == 200:
+			var d: Dictionary = resp["data"]
+			return {
+				"ok": true, "status": 200,
+				"revision": int(d.get("revision", attempt_revision)),
+				"checksum": str(d.get("checksum", "")),
+				"live_session": bool(d.get("live_session", false)),
+				"retried": retried, "detail": "OK",
+			}
+
+		if resp["status"] == 409 and attempt < MAX_RETRIES:
+			var conflict: Dictionary = resp["data"] if resp["data"] is Dictionary else {}
+			var current_rev := int(conflict.get("current_revision", attempt_revision))
+			# Doc-mandated "re-fetch current chunk" step before retrying --
+			# keeps this service's view of the chunk current even though the
+			# retry itself only needs the revision number from the 409 body.
+			await fetch_chunk(coord)
+			attempt_revision = current_rev
+			retried = true
+			continue
+
+		return {"ok": false, "status": resp["status"], "revision": 0, "checksum": "",
+			"live_session": false, "retried": retried, "detail": _error_detail(resp)}
+
+	return {"ok": false, "status": 409, "revision": 0, "checksum": "", "live_session": false,
+		"retried": true, "detail": "conflict retry limit exceeded"}
+
+
+## Save multiple chunks in one atomic batch PUT (world_persistence_impl.md
+## §8.1 batch write: "an editor brush stroke or an object drag routinely
+## straddles a chunk boundary"). `entries` is an Array of
+## `{"coord": Vector3i, "model": ChunkEditorModel, "base_revision": int}`.
+## All-or-nothing: a `409` names the offending coordinate and nothing is
+## written, so only that entry's `base_revision` is refreshed before the
+## whole batch is retried.
+##
+## Returns:
+##     {"ok": bool, "status": int, "live_session": bool,
+##      "chunks": Array, "retried": bool, "detail": String}
+func save_batch(entries: Array) -> Dictionary:
+	var working: Array = []
+	for e in entries:
+		working.append((e as Dictionary).duplicate())
+	var retried := false
+
+	for attempt in range(MAX_RETRIES + 1):
+		var chunks_json: Array = []
+		for e in working:
+			var c: Vector3i = e["coord"]
+			var m: ChunkEditorModel = e["model"]
+			chunks_json.append({
+				"cx": c.x, "cy": c.y, "cz": c.z,
+				"base_revision": int(e["base_revision"]),
+				"payload_b64": Marshalls.raw_to_base64(m.encode_binary()),
+			})
+		var resp := await _request_json(HTTPClient.METHOD_PUT, _batch_path(), {"chunks": chunks_json})
+
+		if resp["status"] == 200:
+			var d: Dictionary = resp["data"]
+			return {"ok": true, "status": 200, "live_session": bool(d.get("live_session", false)),
+				"chunks": d.get("chunks", []), "retried": retried, "detail": "OK"}
+
+		if resp["status"] == 409 and attempt < MAX_RETRIES:
+			var conflict: Dictionary = resp["data"] if resp["data"] is Dictionary else {}
+			var current_rev := int(conflict.get("current_revision", 0))
+			var offending: Variant = conflict.get("coord")
+			if offending is Array and offending.size() == 3:
+				var oc := Vector3i(int(offending[0]), int(offending[1]), int(offending[2]))
+				for e in working:
+					if (e["coord"] as Vector3i) == oc:
+						await fetch_chunk(oc)
+						e["base_revision"] = current_rev
+						break
+			retried = true
+			continue
+
+		return {"ok": false, "status": resp["status"], "live_session": false, "chunks": [],
+			"retried": retried, "detail": _error_detail(resp)}
+
+	return {"ok": false, "status": 409, "live_session": false, "chunks": [],
+		"retried": true, "detail": "conflict retry limit exceeded"}
+
+
+# ─────────────────────────── internals ───────────────────────────
+
+## Resolved via an absolute node path, not the bare `ApiClient` autoload
+## identifier -- see the identical note on `HttpChunkSource._api_client()`
+## (bare autoload identifiers don't resolve when a script is compiled for a
+## headless `godot --script ...` run, which is how this service's smoke
+## test drives it).
+func _api_client() -> Node:
+	return get_node("/root/ApiClient")
+
+
+func _chunk_path(coord: Vector3i) -> String:
+	return "/api/worlds/%s/rooms/%s/chunks/%d/%d/%d" % [world_id, room_slug, coord.x, coord.y, coord.z]
+
+
+func _batch_path() -> String:
+	return "/api/worlds/%s/rooms/%s/chunks" % [world_id, room_slug]
+
+
+func _request_json(method: HTTPClient.Method, path: String, body_dict: Dictionary) -> Dictionary:
+	var http := HTTPRequest.new()
+	http.timeout = 15.0
+	add_child(http)
+
+	var api := _api_client()
+	var headers := PackedStringArray(["Content-Type: application/json", "Accept: application/json"])
+	if api.has_token():
+		headers.append("Authorization: " + str(api.bearer_token))
+
+	var url: String = str(api.base_url) + path
+	var err := http.request(url, headers, method, JSON.stringify(body_dict))
+	if err != OK:
+		http.queue_free()
+		return {"status": 0, "data": null, "raw": "request failed to start (%d)" % err}
+
+	var args: Array = await http.request_completed
+	var result_code: int = args[0]
+	var response_code: int = args[1]
+	var body_bytes: PackedByteArray = args[3]
+	http.queue_free()
+
+	if result_code != HTTPRequest.RESULT_SUCCESS:
+		return {"status": 0, "data": null, "raw": "transport error (%d)" % result_code}
+
+	var text := body_bytes.get_string_from_utf8()
+	var parsed: Variant = JSON.parse_string(text) if text != "" else null
+	return {"status": response_code, "data": parsed, "raw": text}
+
+
+func _error_detail(resp: Dictionary) -> String:
+	var data: Variant = resp.get("data")
+	if data is Dictionary and (data as Dictionary).has("detail"):
+		return str((data as Dictionary)["detail"])
+	if int(resp.get("status", 0)) == 0:
+		return str(resp.get("raw", "network error"))
+	return "HTTP error %d" % int(resp.get("status", 0))
+
+
+func _error_detail_from_body(body: PackedByteArray) -> String:
+	var text := body.get_string_from_utf8()
+	var parsed: Variant = JSON.parse_string(text) if text != "" else null
+	if parsed is Dictionary and (parsed as Dictionary).has("detail"):
+		return str((parsed as Dictionary)["detail"])
+	return text
+
+
+func _fetch_result(ok: bool, status: int, model: ChunkEditorModel, revision: int,
+		checksum: String, detail: String) -> Dictionary:
+	return {"ok": ok, "status": status, "model": model, "revision": revision,
+		"checksum": checksum, "detail": detail}
+
+
+func _int_header(headers: PackedStringArray, key: String) -> int:
+	var prefix := key + ":"
+	for h in headers:
+		if h.to_lower().begins_with(prefix):
+			return int(h.substr(h.find(":") + 1).strip_edges())
+	return 0
+
+
+func _etag_from_headers(headers: PackedStringArray) -> String:
+	for h in headers:
+		if h.to_lower().begins_with("etag:"):
+			var v := h.substr(h.find(":") + 1).strip_edges()
+			return v.trim_prefix('"').trim_suffix('"')
+	return ""

scripts/editor/editor_core.gd

@@ -0,0 +1,114 @@
+class_name EditorCore
+extends RefCounted
+## Shared, data-native editor core (docs/architecture/editor.md §7.1).
+##
+## Both the in-game editor UI (`scripts/editor/ui/in_game_editor.gd`) and,
+## per the doc's §6.2/§7.3, any future thin dev-plugin surface are meant to
+## sit on top of this single object. It never touches `Control` nodes,
+## HTTP, or the live scene tree -- it only knows about the chunk model,
+## undo/redo, selection, and tools. It owns:
+##
+##   - `model`     (ChunkEditorModel)     the chunk being edited
+##   - `undo_redo` (EditorUndoRedoStack)  command-pattern history
+##   - `selection` (SelectionManager)     selected object id
+##   - `tools`     (ToolRegistry)         brush / object_place / select /
+##                                        erase / transform
+##   - `catalog`   (EditorObjectCatalog, optional) palette source consumed
+##                                        by `object_place`
+##
+## Every mutating public method here (`paint_tile`, `erase_tile`,
+## `place_object`, `delete_object`, `move_object`, `rotate_object`,
+## `scale_object`, `select_object`) is a thin wrapper around `use_tool()` --
+## it goes through `ToolRegistry`, never straight at `ChunkEditorModel`.
+## This is the seam this task's verification bar cares about: UI code and
+## tests mutate the chunk exactly the same way, so a test that calls
+## `core.move_object(...)` is exercising the same code path a player's
+## drag-in-the-viewport would.
+##
+## Persisting the edited chunk to the backend is explicitly **out of
+## scope** here (a sibling task owns the batch-PUT/conflict-handling save
+## path per world_persistence_impl.md) -- `model.encode_binary()` is as far
+## as this class goes.
+
+var model: ChunkEditorModel
+var undo_redo: EditorUndoRedoStack
+var selection: SelectionManager
+var tools: ToolRegistry
+var catalog: EditorObjectCatalog = null
+
+
+func _init(p_model: ChunkEditorModel, p_catalog: EditorObjectCatalog = null) -> void:
+	model = p_model
+	catalog = p_catalog
+	undo_redo = EditorUndoRedoStack.new()
+	selection = SelectionManager.new()
+	tools = ToolRegistry.new()
+	tools.register_tool(BrushTool.new())
+	tools.register_tool(ObjectPlaceTool.new())
+	tools.register_tool(SelectTool.new())
+	tools.register_tool(EraseTool.new())
+	tools.register_tool(TransformTool.new())
+	tools.set_active_tool("select")
+
+
+## Route an action through the named tool. This is the single choke point
+## every mutation (and every convenience wrapper below) goes through.
+func use_tool(tool_id: String, args: Dictionary) -> Variant:
+	var tool: EditorTool = tools.get_tool(tool_id)
+	if tool == null:
+		push_error("EditorCore: unknown tool '%s'" % tool_id)
+		return null
+	return tool.apply(self, args)
+
+
+# ───────── convenience wrappers (all route through use_tool/ToolRegistry) ─────────
+
+func paint_tile(layer_idx: int, x: int, y: int, tile_id: int, z: int = 0) -> bool:
+	return bool(use_tool("brush", {"layer": layer_idx, "x": x, "y": y, "z": z, "tile_id": tile_id}))
+
+
+func erase_tile(layer_idx: int, x: int, y: int, z: int = 0) -> bool:
+	return bool(use_tool("erase", {"layer": layer_idx, "x": x, "y": y, "z": z}))
+
+
+func place_object(catalog_id: String, position: Vector3,
+		rotation: Vector4 = Vector4(0, 0, 0, 1), scale: Vector3 = Vector3.ONE) -> String:
+	var result: Variant = use_tool("object_place", {
+		"catalog_id": catalog_id,
+		"position": position,
+		"rotation": rotation,
+		"scale": scale,
+	})
+	return result if result is String else ""
+
+
+func delete_object(object_id: String) -> bool:
+	return bool(use_tool("erase", {"object_id": object_id}))
+
+
+func move_object(object_id: String, position: Vector3) -> bool:
+	return bool(use_tool("transform", {"object_id": object_id, "op": "move", "value": position}))
+
+
+func rotate_object(object_id: String, rotation: Vector4) -> bool:
+	return bool(use_tool("transform", {"object_id": object_id, "op": "rotate", "value": rotation}))
+
+
+func scale_object(object_id: String, scale: Vector3) -> bool:
+	return bool(use_tool("transform", {"object_id": object_id, "op": "scale", "value": scale}))
+
+
+func select_object(object_id: String) -> bool:
+	return bool(use_tool("select", {"object_id": object_id}))
+
+
+func clear_selection() -> void:
+	use_tool("select", {})
+
+
+func undo() -> bool:
+	return undo_redo.undo()
+
+
+func redo() -> bool:
+	return undo_redo.redo()

scripts/editor/editor_undo_redo_stack.gd

@@ -0,0 +1,73 @@
+class_name EditorUndoRedoStack
+extends RefCounted
+## Command pattern over ChunkEditorModel mutations
+## (docs/architecture/editor.md §7.1 `UndoRedoStack`).
+##
+## Thin wrapper around Godot's built-in `UndoRedo` -- the general-purpose
+## class meant for use in game code (unlike the editor-only
+## `EditorUndoRedoManager`, which only exists inside `EditorPlugin`s and
+## isn't available at runtime). Every EditorCore tool (scripts/editor/tools/
+## *.gd) opens exactly one action per user operation and adds a do/undo
+## Callable pair that calls the *same* ChunkEditorModel raw setter in both
+## directions (e.g. `set_tile_raw` with the new id, then again with the old
+## one) -- so undo genuinely reverts the mutation instead of re-deriving it.
+##
+## `UndoRedo` extends `Object`, not `RefCounted`, so it is not automatically
+## freed; `_notification(NOTIFICATION_PREDELETE)` frees it when this wrapper
+## (a RefCounted) goes out of scope.
+
+var _ur := UndoRedo.new()
+
+
+func _notification(what: int) -> void:
+	if what == NOTIFICATION_PREDELETE and _ur != null:
+		_ur.free()
+		_ur = null
+
+
+## Begin a new undoable action. Must be paired with `commit()`.
+func begin(action_name: String) -> void:
+	_ur.create_action(action_name)
+
+
+## Register the forward step of the current action. Called immediately by
+## `commit()`, and again on every future `redo()`.
+func add_do(callable: Callable) -> void:
+	_ur.add_do_method(callable)
+
+
+## Register the reverse step of the current action. Called on every
+## `undo()`.
+func add_undo(callable: Callable) -> void:
+	_ur.add_undo_method(callable)
+
+
+## Close the current action and execute its do-step once.
+func commit() -> void:
+	_ur.commit_action()
+
+
+## Close the current action without executing anything (used when a tool
+## decides mid-way that there is nothing worth recording).
+func cancel() -> void:
+	_ur.commit_action(false)
+
+
+func undo() -> bool:
+	return _ur.undo()
+
+
+func redo() -> bool:
+	return _ur.redo()
+
+
+func can_undo() -> bool:
+	return _ur.has_undo()
+
+
+func can_redo() -> bool:
+	return _ur.has_redo()
+
+
+func clear_history() -> void:
+	_ur.clear_history()

scripts/editor/object_catalog.gd

@@ -0,0 +1,68 @@
+class_name EditorObjectCatalog
+extends RefCounted
+## Catalog of placeable world objects for the in-game editor's
+## `PalettePanel` (docs/architecture/editor.md §7.2).
+##
+## Mirrors the loading convention already used twice in this codebase --
+## `scripts/avatar/avatar_catalog.gd` (AvatarCatalog) and
+## `scripts/scripting/spawn_catalog.gd` (SpawnCatalog): a data-driven JSON
+## manifest, loaded once, looked up by id. Checked both before adding this:
+## `AvatarCatalog` is avatar-attachment-specific (base_body/slot/mount_bone)
+## and `SpawnCatalog` is scoped to `ScriptBehavior`'s `spawn_from_catalog`
+## verb specifically (its own doc comment says as much) -- neither is a
+## general "placeable world object" catalog, so this is a new, small one
+## rather than a reuse of either.
+
+## Catalog manifest structure:
+## { "objects": { "id": { "type", "asset_id", "display_name", ... } } }
+var _catalog: Dictionary = {}
+var _loaded: bool = false
+var _catalog_path: String = "res://assets/editor/object_catalog.json"
+
+
+func load_catalog(path: String = _catalog_path) -> Error:
+	_catalog_path = path
+	_catalog = {}
+
+	var file := FileAccess.open(path, FileAccess.READ)
+	if file == null:
+		return FileAccess.get_open_error()
+
+	var json_text: String = file.get_as_text()
+	file.close()
+
+	var result: Variant = JSON.parse_string(json_text)
+	if result == null or not (result is Dictionary) or not (result as Dictionary).has("objects"):
+		return ERR_INVALID_DATA
+
+	_catalog = (result as Dictionary)["objects"]
+	_loaded = true
+	return OK
+
+
+func is_loaded() -> bool:
+	return _loaded
+
+
+## Resolve a catalog id to its template Dictionary ({} if unknown/unloaded).
+func resolve(id: String) -> Dictionary:
+	if not _loaded:
+		return {}
+	return _catalog.get(id, {})
+
+
+func has_object(id: String) -> bool:
+	return _loaded and _catalog.has(id)
+
+
+func get_all_ids() -> Array[String]:
+	if not _loaded:
+		return []
+	var ids: Array[String] = []
+	for id in _catalog.keys():
+		ids.append(id)
+	return ids
+
+
+func get_catalog_path() -> String:
+	return _catalog_path

scripts/editor/selection_manager.gd

@@ -0,0 +1,32 @@
+class_name SelectionManager
+extends RefCounted
+## Tracks the currently-selected object in the in-game editor
+## (docs/architecture/editor.md §7.1 `SelectionManager`).
+##
+## Selection is UI/session state, not chunk data: it is never pushed onto
+## `EditorUndoRedoStack` and never encoded into the `ChunkPayload`. Scoped
+## to a single selected object id, matching the 2D-tile-editor scope
+## (docs/architecture/editor.md §8) -- multi-select is future work.
+
+signal selection_changed(object_id: String)
+
+var _selected_id: String = ""
+
+
+func select(object_id: String) -> void:
+	if _selected_id == object_id:
+		return
+	_selected_id = object_id
+	selection_changed.emit(_selected_id)
+
+
+func clear() -> void:
+	select("")
+
+
+func get_selected() -> String:
+	return _selected_id
+
+
+func has_selection() -> bool:
+	return _selected_id != ""

scripts/editor/tool_registry.gd

@@ -0,0 +1,41 @@
+class_name ToolRegistry
+extends RefCounted
+## Registry of `EditorTool` instances, keyed by id
+## (docs/architecture/editor.md §7.1: "brush / object-place / select /
+## erase, etc."). `EditorCore.use_tool()` is the single choke point every
+## chunk mutation goes through -- UI code and tests both call tools by id
+## through here rather than reaching into `ChunkEditorModel` directly.
+
+var _tools: Dictionary = {}
+var _active_id: String = ""
+
+
+func register_tool(tool: EditorTool) -> void:
+	_tools[tool.tool_id] = tool
+
+
+func get_tool(tool_id: String) -> EditorTool:
+	return _tools.get(tool_id, null)
+
+
+func has_tool(tool_id: String) -> bool:
+	return _tools.has(tool_id)
+
+
+func get_tool_ids() -> Array:
+	return _tools.keys()
+
+
+func set_active_tool(tool_id: String) -> bool:
+	if not _tools.has(tool_id):
+		return false
+	_active_id = tool_id
+	return true
+
+
+func get_active_tool_id() -> String:
+	return _active_id
+
+
+func get_active_tool() -> EditorTool:
+	return _tools.get(_active_id, null)

scripts/editor/tools/brush_tool.gd

@@ -0,0 +1,31 @@
+class_name BrushTool
+extends EditorTool
+## Paints a single tile id into a tile layer at (x, y[, z]).
+##
+## `args`: `layer` (int, default 0), `x` (int), `y` (int), `z` (int,
+## default 0), `tile_id` (int).
+
+
+func _init() -> void:
+	tool_id = "brush"
+
+
+func apply(core: EditorCore, args: Dictionary) -> Variant:
+	var layer_idx: int = args.get("layer", 0)
+	var x: int = args.get("x", 0)
+	var y: int = args.get("y", 0)
+	var z: int = args.get("z", 0)
+	var tile_id: int = args.get("tile_id", 0)
+
+	if not core.model.is_tile_in_bounds(layer_idx, x, y, z):
+		return false
+
+	var old_tile_id: int = core.model.get_tile_raw(layer_idx, x, y, z)
+	if old_tile_id == tile_id:
+		return false  # no-op -- nothing to undo
+
+	core.undo_redo.begin("Paint tile (%d,%d,%d) -> %d" % [x, y, z, tile_id])
+	core.undo_redo.add_do(core.model.set_tile_raw.bind(layer_idx, x, y, z, tile_id))
+	core.undo_redo.add_undo(core.model.set_tile_raw.bind(layer_idx, x, y, z, old_tile_id))
+	core.undo_redo.commit()
+	return true

scripts/editor/tools/editor_tool.gd

@@ -0,0 +1,20 @@
+class_name EditorTool
+extends RefCounted
+## Base class for EditorCore tools (docs/architecture/editor.md §7.1
+## `ToolRegistry`: brush / object-place / select / erase / transform).
+##
+## A tool never mutates `ChunkEditorModel` "bare" -- every chunk-data
+## mutation goes through `EditorCore.undo_redo` so it is always revertible.
+## (Selection is the one exception: it is UI state, not chunk data, and
+## `SelectTool` intentionally does not touch undo/redo -- see its comment.)
+
+var tool_id: String = ""
+
+
+## Apply this tool's action against `core` with `args`. Returns a
+## tool-specific result on success (often `true`/a new object id), or a
+## falsy value (`false`/`""`/`null`) if nothing changed -- callers should
+## treat falsy as "no-op, nothing to undo".
+func apply(_core: EditorCore, _args: Dictionary) -> Variant:
+	push_error("EditorTool.apply() not implemented for tool '%s'" % tool_id)
+	return null

scripts/editor/tools/erase_tool.gd

@@ -0,0 +1,41 @@
+class_name EraseTool
+extends EditorTool
+## Deletes an object, or clears a tile back to id 0 (the reserved empty/air
+## id -- world.md §3.2 / TileDef doc comment).
+##
+## `args`: either `{"object_id": ...}` to delete an object, or
+## `{"layer", "x", "y", "z"}` to clear a tile (delegates to BrushTool with
+## `tile_id = 0` so both paths share one undo/redo implementation).
+
+
+func _init() -> void:
+	tool_id = "erase"
+
+
+func apply(core: EditorCore, args: Dictionary) -> Variant:
+	if args.has("object_id"):
+		return _erase_object(core, args["object_id"])
+	return _erase_tile(core, args)
+
+
+func _erase_object(core: EditorCore, object_id: String) -> bool:
+	var idx: int = core.model.get_object_index(object_id)
+	if idx == -1:
+		return false
+	var obj: ChunkDataDecoder.WorldObjectData = core.model.payload.objects[idx]
+
+	core.undo_redo.begin("Delete '%s'" % object_id)
+	core.undo_redo.add_do(core.model.remove_object_raw.bind(object_id))
+	core.undo_redo.add_undo(core.model.insert_object_raw.bind(obj, idx))
+	core.undo_redo.commit()
+
+	if core.selection.get_selected() == object_id:
+		core.selection.clear()
+	return true
+
+
+func _erase_tile(core: EditorCore, args: Dictionary) -> bool:
+	var brush: EditorTool = core.tools.get_tool("brush")
+	var tile_args: Dictionary = args.duplicate()
+	tile_args["tile_id"] = 0
+	return bool(brush.apply(core, tile_args))

scripts/editor/tools/object_place_tool.gd

@@ -0,0 +1,50 @@
+class_name ObjectPlaceTool
+extends EditorTool
+## Places a new catalog object into the chunk at a given transform.
+##
+## `args`: `catalog_id` (String, required), `position` (Vector3), `rotation`
+## (Vector4 quaternion, optional, default identity), `scale` (Vector3,
+## optional, default ONE), `properties` (Dictionary, optional, merged in).
+##
+## Returns the new object's id (String) on success, or "" on failure
+## (unknown catalog_id).
+
+
+func _init() -> void:
+	tool_id = "object_place"
+
+
+func apply(core: EditorCore, args: Dictionary) -> Variant:
+	var catalog_id: String = args.get("catalog_id", "")
+	if catalog_id == "":
+		push_error("ObjectPlaceTool: missing catalog_id")
+		return ""
+
+	var entry: Dictionary = {}
+	if core.catalog != null:
+		entry = core.catalog.resolve(catalog_id)
+		if entry.is_empty():
+			push_error("ObjectPlaceTool: unknown catalog_id '%s'" % catalog_id)
+			return ""
+
+	var obj := ChunkDataDecoder.WorldObjectData.new()
+	obj.id = core.model.generate_object_id()
+	obj.type = entry.get("type", "prop")
+	obj.asset_id = entry.get("asset_id", catalog_id)
+	obj.position = args.get("position", Vector3.ZERO)
+	obj.rotation = args.get("rotation", Vector4(0, 0, 0, 1))
+	obj.scale = args.get("scale", Vector3.ONE)
+
+	var props: Dictionary = (args.get("properties", {}) as Dictionary).duplicate()
+	if entry.has("display_name"):
+		props["display_name"] = entry["display_name"]
+	props["catalog_id"] = catalog_id
+	obj.properties = props
+
+	core.undo_redo.begin("Place '%s' (%s)" % [obj.id, catalog_id])
+	core.undo_redo.add_do(core.model.add_object_raw.bind(obj))
+	core.undo_redo.add_undo(core.model.remove_object_raw.bind(obj.id))
+	core.undo_redo.commit()
+
+	core.selection.select(obj.id)
+	return obj.id

scripts/editor/tools/select_tool.gd

@@ -0,0 +1,24 @@
+class_name SelectTool
+extends EditorTool
+## Selects (or clears) the active object in `EditorCore.selection`.
+##
+## `args`: `object_id` (String) -- omitted or "" clears the selection.
+##
+## Selection is UI/session state, not chunk data (docs/architecture/editor.md
+## §7.1 lists `SelectionManager` as a sibling of `UndoRedoStack`, not a
+## client of it), so this intentionally never touches `core.undo_redo`.
+
+
+func _init() -> void:
+	tool_id = "select"
+
+
+func apply(core: EditorCore, args: Dictionary) -> Variant:
+	var object_id: String = args.get("object_id", "")
+	if object_id == "":
+		core.selection.clear()
+		return true
+	if core.model.find_object(object_id) == null:
+		return false
+	core.selection.select(object_id)
+	return true

scripts/editor/tools/transform_tool.gd

@@ -0,0 +1,62 @@
+class_name TransformTool
+extends EditorTool
+## Moves, rotates, or scales an existing object.
+##
+## Not one of the four tools literally named in docs/architecture/editor.md
+## §7.1's `ToolRegistry` list ("brush / object-place / select / erase,
+## etc.") but required by this task's brief ("place / move / rotate / scale
+## / delete") -- the doc's own "etc." leaves room, so this is a fifth
+## registered tool rather than overloading `ObjectPlaceTool` (placing a new
+## object and re-transforming an existing one are different undo units)
+## or `SelectTool` (selection is deliberately not chunk-mutating).
+##
+## `args`: `object_id` (String), `op` ("move" | "rotate" | "scale"), `value`
+## (Vector3 for move/scale, Vector4 quaternion for rotate).
+
+
+func _init() -> void:
+	tool_id = "transform"
+
+
+func apply(core: EditorCore, args: Dictionary) -> Variant:
+	var object_id: String = args.get("object_id", "")
+	var op: String = args.get("op", "")
+	var obj := core.model.find_object(object_id)
+	if obj == null:
+		return false
+
+	match op:
+		"move":
+			return _apply_vector3(core, object_id, args.get("value", obj.position),
+				obj.position, "Move", core.model.set_object_position_raw)
+		"rotate":
+			return _apply_vector4(core, object_id, args.get("value", obj.rotation),
+				obj.rotation, "Rotate", core.model.set_object_rotation_raw)
+		"scale":
+			return _apply_vector3(core, object_id, args.get("value", obj.scale),
+				obj.scale, "Scale", core.model.set_object_scale_raw)
+		_:
+			push_error("TransformTool: unknown op '%s'" % op)
+			return false
+
+
+func _apply_vector3(core: EditorCore, object_id: String, new_value: Vector3,
+		old_value: Vector3, label: String, setter: Callable) -> bool:
+	if new_value.is_equal_approx(old_value):
+		return false
+	core.undo_redo.begin("%s '%s'" % [label, object_id])
+	core.undo_redo.add_do(setter.bind(object_id, new_value))
+	core.undo_redo.add_undo(setter.bind(object_id, old_value))
+	core.undo_redo.commit()
+	return true
+
+
+func _apply_vector4(core: EditorCore, object_id: String, new_value: Vector4,
+		old_value: Vector4, label: String, setter: Callable) -> bool:
+	if new_value.is_equal_approx(old_value):
+		return false
+	core.undo_redo.begin("%s '%s'" % [label, object_id])
+	core.undo_redo.add_do(setter.bind(object_id, new_value))
+	core.undo_redo.add_undo(setter.bind(object_id, old_value))
+	core.undo_redo.commit()
+	return true

scripts/editor/ui/editor_toolbar.gd

@@ -0,0 +1,65 @@
+class_name EditorToolbar
+extends HBoxContainer
+## Tool-mode switcher for the in-game editor (docs/architecture/editor.md
+## §7.2 `Toolbar`). Pure UI: it only emits signals: `InGameEditor` decides
+## what to do with them (calling into `EditorCore`/`ToolRegistry`).
+
+signal tool_selected(tool_id: String)
+signal undo_pressed
+signal redo_pressed
+
+const TOOL_LABELS := {
+	"select": "Select",
+	"brush": "Brush",
+	"object_place": "Place",
+	"erase": "Erase",
+}
+
+var _tool_buttons: Dictionary = {}
+var _undo_button: Button
+var _redo_button: Button
+
+
+func _init() -> void:
+	name = "EditorToolbar"
+
+
+func _ready() -> void:
+	for tool_id in TOOL_LABELS:
+		var btn := Button.new()
+		btn.text = TOOL_LABELS[tool_id]
+		btn.toggle_mode = true
+		btn.pressed.connect(_on_tool_button_pressed.bind(tool_id))
+		add_child(btn)
+		_tool_buttons[tool_id] = btn
+
+	add_child(VSeparator.new())
+
+	_undo_button = Button.new()
+	_undo_button.text = "Undo"
+	_undo_button.pressed.connect(func(): undo_pressed.emit())
+	add_child(_undo_button)
+
+	_redo_button = Button.new()
+	_redo_button.text = "Redo"
+	_redo_button.pressed.connect(func(): redo_pressed.emit())
+	add_child(_redo_button)
+
+
+func _on_tool_button_pressed(tool_id: String) -> void:
+	set_active_tool(tool_id)
+	tool_selected.emit(tool_id)
+
+
+## Reflect the active tool in the button states without re-emitting the signal.
+func set_active_tool(tool_id: String) -> void:
+	for id in _tool_buttons:
+		_tool_buttons[id].button_pressed = (id == tool_id)
+
+
+## Reflect whether undo/redo currently have anything to do.
+func set_history_state(can_undo: bool, can_redo: bool) -> void:
+	if _undo_button:
+		_undo_button.disabled = not can_undo
+	if _redo_button:
+		_redo_button.disabled = not can_redo

scripts/editor/ui/editor_viewport.gd

@@ -0,0 +1,135 @@
+class_name EditorViewport
+extends Control
+## Custom 2D viewport for the in-game editor (docs/architecture/editor.md
+## §7.2 `EditorViewport`).
+##
+## Deliberately 2D top-down, not a 3D gizmo viewport -- per §8's own risk
+## mitigation ("start with a 2D tile editor... matches CHUNK_SIZE_Z=1
+## default; add 3D later"). Renders one tile layer as a grid plus the
+## chunk's objects as dots, and turns clicks into calls on `EditorCore`
+## routed through whichever tool is active in `ToolRegistry` -- this is UI
+## glue, it never mutates `ChunkEditorModel` itself.
+##
+## Coordinate convention matches the rest of this codebase's tile system
+## (scripts/tile_layer_node.gd `_tile_to_world`): chunk-local X/Y are the
+## flat ground plane, Z is height (CHUNK_SIZE_Z=1 by default -- see
+## scripts/chunk.gd). One grid cell == one world unit == `cell_size` pixels.
+
+signal edit_applied
+
+var core: EditorCore = null
+var layer_idx: int = 0
+var cell_size: float = 24.0
+## Catalog id the next "object_place" click will place. Set by
+## `InGameEditor` from `PalettePanel.object_selected`.
+var pending_catalog_id: String = ""
+## Tile id the next "brush" click paints. Cycled with number keys 0-9.
+var current_tile_id: int = 1
+
+const TILE_EMPTY_COLOR := Color(0.15, 0.15, 0.17)
+const TILE_SOLID_COLOR := Color(0.35, 0.55, 0.35)
+const GRID_COLOR := Color(0, 0, 0, 0.25)
+const OBJECT_COLOR := Color(0.9, 0.6, 0.2)
+const OBJECT_SELECTED_COLOR := Color(1.0, 0.95, 0.2)
+
+
+func _init() -> void:
+	name = "EditorViewport"
+	mouse_filter = Control.MOUSE_FILTER_STOP
+	focus_mode = Control.FOCUS_ALL
+
+
+func setup(p_core: EditorCore, p_layer_idx: int = 0) -> void:
+	core = p_core
+	layer_idx = p_layer_idx
+	core.selection.selection_changed.connect(func(_id): queue_redraw())
+	_resize_to_layer()
+	queue_redraw()
+
+
+func _resize_to_layer() -> void:
+	var layer := core.model.get_layer(layer_idx)
+	if layer == null:
+		custom_minimum_size = Vector2(cell_size * 8, cell_size * 8)
+		return
+	custom_minimum_size = Vector2(layer.width * cell_size, layer.height * cell_size)
+
+
+func _draw() -> void:
+	if core == null:
+		return
+	var layer := core.model.get_layer(layer_idx)
+	if layer == null:
+		return
+
+	for y in range(layer.height):
+		for x in range(layer.width):
+			var tile_id := layer.get_tile(x, y, 0)
+			var color := TILE_EMPTY_COLOR
+			var tdef := layer.get_tile_def(tile_id)
+			if tdef != null and tdef.solid:
+				color = TILE_SOLID_COLOR
+			draw_rect(Rect2(x * cell_size, y * cell_size, cell_size, cell_size), color, true)
+
+	for x in range(layer.width + 1):
+		draw_line(Vector2(x * cell_size, 0), Vector2(x * cell_size, layer.height * cell_size), GRID_COLOR)
+	for y in range(layer.height + 1):
+		draw_line(Vector2(0, y * cell_size), Vector2(layer.width * cell_size, y * cell_size), GRID_COLOR)
+
+	for obj in core.model.payload.objects:
+		var center := Vector2(obj.position.x * cell_size, obj.position.y * cell_size)
+		var is_selected: bool = core.selection.get_selected() == obj.id
+		var color := OBJECT_SELECTED_COLOR if is_selected else OBJECT_COLOR
+		draw_circle(center, cell_size * 0.3, color)
+
+
+func _gui_input(event: InputEvent) -> void:
+	if core == null:
+		return
+	if event is InputEventMouseButton:
+		var mb := event as InputEventMouseButton
+		if mb.pressed and mb.button_index == MOUSE_BUTTON_LEFT:
+			_handle_click(mb.position)
+			accept_event()
+	elif event is InputEventKey:
+		var key := event as InputEventKey
+		if key.pressed and not key.echo:
+			_handle_key(key)
+
+
+func _handle_key(key: InputEventKey) -> void:
+	if key.keycode >= KEY_0 and key.keycode <= KEY_9:
+		current_tile_id = key.keycode - KEY_0
+
+
+func _handle_click(local_pos: Vector2) -> void:
+	var tx := int(floor(local_pos.x / cell_size))
+	var ty := int(floor(local_pos.y / cell_size))
+
+	match core.tools.get_active_tool_id():
+		"brush":
+			if core.paint_tile(layer_idx, tx, ty, current_tile_id):
+				edit_applied.emit()
+				queue_redraw()
+		"erase":
+			var hit := _object_at(tx, ty)
+			var changed: bool = core.delete_object(hit) if hit != "" else core.erase_tile(layer_idx, tx, ty)
+			if changed:
+				edit_applied.emit()
+				queue_redraw()
+		"object_place":
+			if pending_catalog_id != "":
+				var new_id := core.place_object(pending_catalog_id, Vector3(tx + 0.5, ty + 0.5, 0.0))
+				if new_id != "":
+					edit_applied.emit()
+					queue_redraw()
+		"select":
+			core.select_object(_object_at(tx, ty))
+			queue_redraw()
+
+
+func _object_at(tx: int, ty: int) -> String:
+	for obj in core.model.payload.objects:
+		if int(floor(obj.position.x)) == tx and int(floor(obj.position.y)) == ty:
+			return obj.id
+	return ""

scripts/editor/ui/in_game_editor.gd

@@ -0,0 +1,250 @@
+class_name InGameEditor
+extends Control
+## In-game "build mode" UI (docs/architecture/editor.md §7.2 `InGameEditor`).
+##
+## Built entirely from `Control` nodes in code (matching this codebase's
+## existing convention for dynamic UI -- see `game.gd`'s `_show_build_stamp`
+## / `_show_status`) rather than a hand-authored `.tscn`, so there is one
+## fewer place for a scene-file/script mismatch to hide. It is only ever
+## instantiated when the player enters build mode (see `game.gd`'s
+## `_toggle_build_mode`), so it costs nothing during normal play.
+##
+## Composition matches the doc exactly:
+##   EditorToolbar   -- tool mode switcher
+##   PalettePanel    -- catalog-sourced object palette
+##   EditorViewport   -- the 2D tile/object canvas
+##   InspectorPanel  -- property editor for the selected object
+##   EditorCore      -- shared core (passed in, not owned/created here)
+##
+## Persisting edits (world_persistence_impl.md's single/batch-PUT save path,
+## §8.1-8.2) is wired through `ChunkSaveService`, set via
+## `setup_persistence()`. Without it (e.g. the F2 scratch-chunk path, or
+## `smoke_test_editor_core.gd`'s bare `InGameEditor.new(core)`), the Save
+## button is present but disabled -- closing the editor just discards the
+## UI and the in-memory `ChunkEditorModel` is unaffected either way.
+
+signal closed
+
+var core: EditorCore
+
+var _toolbar: EditorToolbar
+var _palette: PalettePanel
+var _inspector: InspectorPanel
+var _viewport: EditorViewport
+var _close_button: Button
+var _save_button: Button
+var _save_status_label: Label
+
+## Save-path state (world_persistence_impl.md §8.1/§8.2), set via
+## `setup_persistence()`. `_save_service == null` means there is nothing to
+## save to (see the class doc above) -- the Save button stays disabled.
+var _save_service: ChunkSaveService = null
+var _world_id: String = ""
+var _room_slug: String = "main"
+var _coord: Vector3i = Vector3i.ZERO
+var _base_revision: int = 0
+var _saving: bool = false
+
+
+func _init(p_core: EditorCore) -> void:
+	core = p_core
+	name = "InGameEditor"
+	set_anchors_preset(Control.PRESET_FULL_RECT)
+	mouse_filter = Control.MOUSE_FILTER_STOP
+
+
+## Wire this editor's Save button/Ctrl+S to a real backend round-trip.
+## `save_service` must already be in the scene tree (game.gd adds it as a
+## sibling before constructing this editor). `base_revision` is whatever the
+## caller last fetched for `coord` (0 if the chunk didn't exist yet).
+func setup_persistence(save_service: ChunkSaveService, world_id: String, room_slug: String,
+		coord: Vector3i, base_revision: int) -> void:
+	_save_service = save_service
+	_world_id = world_id
+	_room_slug = room_slug
+	_coord = coord
+	_base_revision = base_revision
+	if _save_button != null:
+		_save_button.disabled = false
+
+
+func _ready() -> void:
+	_build_ui()
+	_refresh_history_buttons()
+
+
+func _build_ui() -> void:
+	var bg := ColorRect.new()
+	bg.color = Color(0.08, 0.08, 0.09, 0.96)
+	bg.set_anchors_preset(Control.PRESET_FULL_RECT)
+	bg.mouse_filter = Control.MOUSE_FILTER_IGNORE
+	add_child(bg)
+
+	var root_vbox := VBoxContainer.new()
+	root_vbox.set_anchors_preset(Control.PRESET_FULL_RECT)
+	root_vbox.offset_left = 12
+	root_vbox.offset_top = 12
+	root_vbox.offset_right = -12
+	root_vbox.offset_bottom = -12
+	add_child(root_vbox)
+
+	var top_bar := HBoxContainer.new()
+	root_vbox.add_child(top_bar)
+
+	_toolbar = EditorToolbar.new()
+	_toolbar.size_flags_horizontal = Control.SIZE_EXPAND_FILL
+	top_bar.add_child(_toolbar)
+
+	_save_button = Button.new()
+	_save_button.text = "Save (Ctrl+S)"
+	_save_button.disabled = (_save_service == null)
+	_save_button.pressed.connect(_on_save_pressed)
+	top_bar.add_child(_save_button)
+
+	_close_button = Button.new()
+	_close_button.text = "Close (F2)"
+	_close_button.pressed.connect(_on_close_pressed)
+	top_bar.add_child(_close_button)
+
+	_save_status_label = Label.new()
+	_save_status_label.autowrap_mode = TextServer.AUTOWRAP_WORD
+	_save_status_label.visible = false
+	root_vbox.add_child(_save_status_label)
+
+	var body := HBoxContainer.new()
+	body.size_flags_vertical = Control.SIZE_EXPAND_FILL
+	root_vbox.add_child(body)
+
+	var viewport_scroll := ScrollContainer.new()
+	viewport_scroll.size_flags_horizontal = Control.SIZE_EXPAND_FILL
+	viewport_scroll.size_flags_vertical = Control.SIZE_EXPAND_FILL
+	body.add_child(viewport_scroll)
+
+	_viewport = EditorViewport.new()
+	viewport_scroll.add_child(_viewport)
+
+	var sidebar := VBoxContainer.new()
+	sidebar.custom_minimum_size = Vector2(240, 0)
+	body.add_child(sidebar)
+
+	_palette = PalettePanel.new()
+	sidebar.add_child(_palette)
+
+	_inspector = InspectorPanel.new()
+	sidebar.add_child(_inspector)
+
+	_viewport.setup(core, 0)
+	_palette.set_catalog(core.catalog)
+	_inspector.setup(core)
+
+	_toolbar.set_active_tool(core.tools.get_active_tool_id())
+	_toolbar.tool_selected.connect(_on_tool_selected)
+	_toolbar.undo_pressed.connect(_on_undo_pressed)
+	_toolbar.redo_pressed.connect(_on_redo_pressed)
+	_palette.object_selected.connect(_on_palette_object_selected)
+	_inspector.delete_requested.connect(_on_inspector_delete_requested)
+	_viewport.edit_applied.connect(_on_edit_applied)
+	core.selection.selection_changed.connect(_on_selection_changed)
+
+
+func _unhandled_key_input(event: InputEvent) -> void:
+	if not (event is InputEventKey):
+		return
+	var key := event as InputEventKey
+	if not key.pressed or key.echo:
+		return
+	if key.ctrl_pressed and key.keycode == KEY_Z:
+		_on_undo_pressed()
+		get_viewport().set_input_as_handled()
+	elif key.ctrl_pressed and key.keycode == KEY_Y:
+		_on_redo_pressed()
+		get_viewport().set_input_as_handled()
+	elif key.ctrl_pressed and key.keycode == KEY_S:
+		_on_save_pressed()
+		get_viewport().set_input_as_handled()
+	elif key.keycode == KEY_DELETE and core.selection.has_selection():
+		core.delete_object(core.selection.get_selected())
+		_on_edit_applied()
+		get_viewport().set_input_as_handled()
+
+
+func _on_tool_selected(tool_id: String) -> void:
+	core.tools.set_active_tool(tool_id)
+
+
+func _on_palette_object_selected(catalog_id: String) -> void:
+	_viewport.pending_catalog_id = catalog_id
+	core.tools.set_active_tool("object_place")
+	_toolbar.set_active_tool("object_place")
+
+
+func _on_inspector_delete_requested(object_id: String) -> void:
+	core.delete_object(object_id)
+	_on_edit_applied()
+
+
+func _on_undo_pressed() -> void:
+	core.undo()
+	_on_edit_applied()
+
+
+func _on_redo_pressed() -> void:
+	core.redo()
+	_on_edit_applied()
+
+
+func _on_edit_applied() -> void:
+	_viewport.queue_redraw()
+	_inspector.show_object(core.selection.get_selected())
+	_refresh_history_buttons()
+
+
+func _on_selection_changed(object_id: String) -> void:
+	_inspector.show_object(object_id)
+
+
+func _refresh_history_buttons() -> void:
+	_toolbar.set_history_state(core.undo_redo.can_undo(), core.undo_redo.can_redo())
+
+
+func _on_close_pressed() -> void:
+	closed.emit()
+	queue_free()
+
+
+## Single-chunk save (world_persistence_impl.md §8.1). `ChunkSaveService`
+## owns the actual HTTP round trip, retrying on `409` internally
+## (§8.2/§5.4) -- this just reflects the outcome and, per §6 D4, surfaces
+## the `live_session` flag as a warning instead of ignoring it.
+func _on_save_pressed() -> void:
+	if _save_service == null or _saving:
+		return
+	_saving = true
+	_save_button.disabled = true
+	_set_save_status("Saving…", Color(0.85, 0.85, 0.85))
+
+	var result: Dictionary = await _save_service.save_chunk(core.model, _coord, _base_revision)
+
+	_saving = false
+	_save_button.disabled = false
+
+	if result.get("ok", false):
+		_base_revision = int(result.get("revision", _base_revision))
+		var msg := "Saved (revision %d)." % _base_revision
+		if bool(result.get("retried", false)):
+			msg += " (resolved a save conflict automatically)"
+		if bool(result.get("live_session", false)):
+			msg += " This world has players in it right now -- they'll see your changes when the session restarts."
+			_set_save_status(msg, Color(1.0, 0.8, 0.25))
+		else:
+			_set_save_status(msg, Color(0.55, 1.0, 0.55))
+	else:
+		_set_save_status("Save failed: %s" % str(result.get("detail", "unknown error")), Color(1.0, 0.45, 0.45))
+
+
+func _set_save_status(text: String, color: Color) -> void:
+	if _save_status_label == null:
+		return
+	_save_status_label.text = text
+	_save_status_label.add_theme_color_override("font_color", color)
+	_save_status_label.visible = true

scripts/editor/ui/inspector_panel.gd

@@ -0,0 +1,166 @@
+class_name InspectorPanel
+extends VBoxContainer
+## Property editor for the selected object (docs/architecture/editor.md
+## §7.2 `InspectorPanel`).
+##
+## 2D-tile-editor scope (docs/architecture/editor.md §8: the default world
+## is flat, `CHUNK_SIZE_Z=1`): position exposes X/Y (world-plane) plus a
+## single "height" Z for props that sit above the floor, and rotation
+## exposes one yaw field (rotation about the vertical axis) rather than a
+## full 3-axis gizmo -- deliberately not the volumetric 3D editing the doc
+## says to defer.
+##
+## Pure UI: every edit calls back into `EditorCore` (`move_object` /
+## `rotate_object` / `scale_object` / `delete_object`), so inspector edits
+## go through the exact same undo/redo path as viewport edits.
+
+signal delete_requested(object_id: String)
+
+var _core: EditorCore = null
+var _object_id: String = ""
+var _updating := false  # guards against feedback loops while refreshing fields
+
+var _id_label: Label
+var _type_label: Label
+var _asset_label: Label
+var _pos_x: SpinBox
+var _pos_y: SpinBox
+var _pos_z: SpinBox
+var _yaw: SpinBox
+var _scale_x: SpinBox
+var _scale_y: SpinBox
+var _scale_z: SpinBox
+var _delete_button: Button
+var _empty_label: Label
+var _fields_box: VBoxContainer
+
+
+func _init() -> void:
+	name = "InspectorPanel"
+
+
+func _ready() -> void:
+	var header := Label.new()
+	header.text = "Inspector"
+	add_child(header)
+
+	_empty_label = Label.new()
+	_empty_label.text = "(nothing selected)"
+	add_child(_empty_label)
+
+	_fields_box = VBoxContainer.new()
+	_fields_box.visible = false
+	add_child(_fields_box)
+
+	_id_label = _add_readonly_row("id")
+	_type_label = _add_readonly_row("type")
+	_asset_label = _add_readonly_row("asset")
+
+	_pos_x = _add_spinbox_row("pos x")
+	_pos_y = _add_spinbox_row("pos y")
+	_pos_z = _add_spinbox_row("pos z (height)")
+	_pos_x.value_changed.connect(_on_position_changed)
+	_pos_y.value_changed.connect(_on_position_changed)
+	_pos_z.value_changed.connect(_on_position_changed)
+
+	_yaw = _add_spinbox_row("rotation (deg)")
+	_yaw.min_value = -360.0
+	_yaw.max_value = 360.0
+	_yaw.step = 1.0
+	_yaw.value_changed.connect(_on_yaw_changed)
+
+	_scale_x = _add_spinbox_row("scale x")
+	_scale_y = _add_spinbox_row("scale y")
+	_scale_z = _add_spinbox_row("scale z")
+	_scale_x.value_changed.connect(_on_scale_changed)
+	_scale_y.value_changed.connect(_on_scale_changed)
+	_scale_z.value_changed.connect(_on_scale_changed)
+
+	_delete_button = Button.new()
+	_delete_button.text = "Delete"
+	_delete_button.pressed.connect(_on_delete_pressed)
+	_fields_box.add_child(_delete_button)
+
+
+func setup(core: EditorCore) -> void:
+	_core = core
+
+
+func show_object(object_id: String) -> void:
+	_object_id = object_id
+	if object_id == "" or _core == null:
+		_empty_label.visible = true
+		_fields_box.visible = false
+		return
+
+	var obj := _core.model.find_object(object_id)
+	if obj == null:
+		_empty_label.visible = true
+		_fields_box.visible = false
+		return
+
+	_empty_label.visible = false
+	_fields_box.visible = true
+
+	_updating = true
+	_id_label.text = "id: %s" % obj.id
+	_type_label.text = "type: %s" % obj.type
+	_asset_label.text = "asset: %s" % obj.asset_id
+	_pos_x.value = obj.position.x
+	_pos_y.value = obj.position.y
+	_pos_z.value = obj.position.z
+	_yaw.value = rad_to_deg(Quaternion(obj.rotation.x, obj.rotation.y, obj.rotation.z, obj.rotation.w).get_euler().y)
+	_scale_x.value = obj.scale.x
+	_scale_y.value = obj.scale.y
+	_scale_z.value = obj.scale.z
+	_updating = false
+
+
+func _on_position_changed(_v: float) -> void:
+	if _updating or _core == null or _object_id == "":
+		return
+	_core.move_object(_object_id, Vector3(_pos_x.value, _pos_y.value, _pos_z.value))
+
+
+func _on_yaw_changed(v: float) -> void:
+	if _updating or _core == null or _object_id == "":
+		return
+	var quat := Quaternion(Vector3.UP, deg_to_rad(v))
+	_core.rotate_object(_object_id, Vector4(quat.x, quat.y, quat.z, quat.w))
+
+
+func _on_scale_changed(_v: float) -> void:
+	if _updating or _core == null or _object_id == "":
+		return
+	_core.scale_object(_object_id, Vector3(_scale_x.value, _scale_y.value, _scale_z.value))
+
+
+func _on_delete_pressed() -> void:
+	if _object_id == "":
+		return
+	var id := _object_id
+	delete_requested.emit(id)
+
+
+func _add_readonly_row(label: String) -> Label:
+	var l := Label.new()
+	l.text = "%s: " % label
+	_fields_box.add_child(l)
+	return l
+
+
+func _add_spinbox_row(label_text: String) -> SpinBox:
+	var row := HBoxContainer.new()
+	var l := Label.new()
+	l.text = label_text
+	l.custom_minimum_size = Vector2(90, 0)
+	row.add_child(l)
+	var sb := SpinBox.new()
+	sb.min_value = -100000.0
+	sb.max_value = 100000.0
+	sb.step = 0.1
+	sb.allow_greater = true
+	sb.allow_lesser = true
+	row.add_child(sb)
+	_fields_box.add_child(row)
+	return sb

scripts/editor/ui/palette_panel.gd

@@ -0,0 +1,57 @@
+class_name PalettePanel
+extends VBoxContainer
+## Catalog-sourced object palette (docs/architecture/editor.md §7.2
+## `PalettePanel`). Lists every id in an `EditorObjectCatalog` and emits
+## which one the player picked; `InGameEditor` remembers it as the pending
+## `catalog_id` for the next `ObjectPlaceTool` placement.
+
+signal object_selected(catalog_id: String)
+
+var _list: ItemList
+var _catalog: EditorObjectCatalog = null
+var _ids: Array[String] = []
+
+
+func _init() -> void:
+	name = "PalettePanel"
+
+
+func _ready() -> void:
+	var header := Label.new()
+	header.text = "Palette"
+	add_child(header)
+
+	_list = ItemList.new()
+	_list.size_flags_vertical = Control.SIZE_EXPAND_FILL
+	_list.item_selected.connect(_on_item_selected)
+	add_child(_list)
+
+
+func set_catalog(catalog: EditorObjectCatalog) -> void:
+	_catalog = catalog
+	_refresh()
+
+
+func _refresh() -> void:
+	_list.clear()
+	_ids.clear()
+	if _catalog == null or not _catalog.is_loaded():
+		return
+	for id in _catalog.get_all_ids():
+		var entry := _catalog.resolve(id)
+		var label: String = entry.get("display_name", id)
+		_list.add_item(label)
+		_ids.append(id)
+
+
+func _on_item_selected(index: int) -> void:
+	if index < 0 or index >= _ids.size():
+		return
+	object_selected.emit(_ids[index])
+
+
+func get_selected_catalog_id() -> String:
+	var selected: PackedInt32Array = _list.get_selected_items()
+	if selected.is_empty():
+		return ""
+	return _ids[selected[0]]

scripts/friends_presence_ui.gd

@@ -0,0 +1,444 @@
+extends Control
+class_name FriendsPresenceUI
+## Friends & Presence UI panel.
+##
+## Displays:
+## - Friends list with real-time online/offline presence & custom status
+## - Friend requests inbox (with Accept / Decline / Send actions)
+## - Following list (with Unfollow / Follow actions)
+## - Blocked users list (with Unblock / Block actions)
+## - Custom status updater
+
+signal back_requested
+
+@onready var back_button: Button = $VBoxContainer/HeaderHBox/BackButton
+@onready var refresh_button: Button = $VBoxContainer/HeaderHBox/RefreshButton
+@onready var status_label: Label = $VBoxContainer/StatusMessageLabel
+
+@onready var tab_container: TabContainer = $VBoxContainer/TabContainer
+@onready var friends_container: VBoxContainer = $VBoxContainer/TabContainer/Friends/Scroll/FriendsList
+@onready var requests_container: VBoxContainer = $VBoxContainer/TabContainer/Requests/Scroll/RequestsList
+@onready var following_container: VBoxContainer = $VBoxContainer/TabContainer/Following/Scroll/FollowingList
+@onready var blocked_container: VBoxContainer = $VBoxContainer/TabContainer/Blocked/Scroll/BlockedList
+
+@onready var custom_status_input: LineEdit = $VBoxContainer/MyStatusHBox/StatusLineEdit
+@onready var set_status_button: Button = $VBoxContainer/MyStatusHBox/SetStatusButton
+
+# Friend request input
+@onready var send_req_input: LineEdit = $VBoxContainer/TabContainer/Requests/SendHBox/TargetUserIdEdit
+@onready var send_req_button: Button = $VBoxContainer/TabContainer/Requests/SendHBox/SendButton
+
+# Follow input
+@onready var follow_input: LineEdit = $VBoxContainer/TabContainer/Following/FollowHBox/FollowUserIdEdit
+@onready var follow_button: Button = $VBoxContainer/TabContainer/Following/FollowHBox/FollowButton
+
+# Block input
+@onready var block_input: LineEdit = $VBoxContainer/TabContainer/Blocked/BlockHBox/BlockUserIdEdit
+@onready var block_button: Button = $VBoxContainer/TabContainer/Blocked/BlockHBox/BlockButton
+
+var _api_client: Node = null
+var _friend_presence_map: Dictionary = {} # user_id (int) -> {"status": String, "custom_status": String, "last_seen": String}
+
+
+func _ready() -> void:
+	_api_client = _get_api()
+	_wire_signals()
+	if _api_client != null and _api_client.has_token():
+		refresh_all()
+
+
+func _get_api() -> Node:
+	if has_node("/root/ApiClient"):
+		return get_node("/root/ApiClient")
+	return null
+
+
+func _wire_signals() -> void:
+	if back_button:
+		back_button.pressed.connect(_on_back_pressed)
+	if refresh_button:
+		refresh_button.pressed.connect(refresh_all)
+	if set_status_button:
+		set_status_button.pressed.connect(_on_set_status_pressed)
+	if send_req_button:
+		send_req_button.pressed.connect(_on_send_req_pressed)
+	if follow_button:
+		follow_button.pressed.connect(_on_follow_pressed)
+	if block_button:
+		block_button.pressed.connect(_on_block_pressed)
+
+	if _api_client != null and _api_client.ws != null:
+		if not _api_client.ws.presence_changed.is_connected(_on_presence_changed):
+			_api_client.ws.presence_changed.connect(_on_presence_changed)
+
+
+func _on_back_pressed() -> void:
+	back_requested.emit()
+	if get_tree().current_scene == self:
+		get_tree().change_scene_to_file("res://scenes/main_menu.tscn")
+
+
+func show_message(text: String, is_error: bool = false) -> void:
+	if status_label:
+		status_label.text = text
+		status_label.modulate = Color(1.0, 0.4, 0.4) if is_error else Color(0.4, 1.0, 0.4)
+
+
+func refresh_all() -> void:
+	if _api_client == null or not _api_client.has_token():
+		show_message("Please log in to view social features.", true)
+		return
+
+	await refresh_friends()
+	await refresh_requests()
+	await refresh_following()
+	await refresh_blocked()
+
+
+# ── Friends & Presence ──
+
+func refresh_friends() -> void:
+	if _api_client == null:
+		return
+
+	# Fetch mutual presence first
+	var pres_res: Dictionary = await _api_client.get_friends_presence()
+	_friend_presence_map.clear()
+	if pres_res.ok and pres_res.data is Dictionary and pres_res.data.has("friends"):
+		for p in pres_res.data["friends"]:
+			var uid: int = int(p.get("user_id", 0))
+			_friend_presence_map[uid] = p
+
+	# Fetch friends list
+	var res: Dictionary = await _api_client.get_friends()
+	_clear_children(friends_container)
+
+	if not res.ok:
+		show_message("Failed to load friends: " + res.detail, true)
+		return
+
+	var friends_list: Array = []
+	if res.data is Dictionary and res.data.has("friends"):
+		friends_list = res.data["friends"]
+
+	if friends_list.is_empty():
+		var empty_label := Label.new()
+		empty_label.text = "No friends yet. Send a friend request to get started!"
+		empty_label.modulate = Color(0.7, 0.7, 0.7)
+		friends_container.add_child(empty_label)
+		return
+
+	for friend in friends_list:
+		var uid: int = int(friend.get("id", 0))
+		var uname: String = str(friend.get("username", "Unknown"))
+		_build_friend_row(uid, uname)
+
+
+func _build_friend_row(uid: int, uname: String) -> void:
+	var hbox := HBoxContainer.new()
+	hbox.name = "FriendRow_%d" % uid
+	hbox.add_theme_constant_override("separation", 12)
+
+	var pres: Dictionary = _friend_presence_map.get(uid, {})
+	var is_online: bool = pres.get("status", "offline") == "online"
+	var custom_status: String = str(pres.get("custom_status", ""))
+	var last_seen: String = str(pres.get("last_seen", ""))
+
+	# Status indicator dot
+	var status_dot := Label.new()
+	status_dot.text = "●"
+	status_dot.modulate = Color(0.2, 0.9, 0.2) if is_online else Color(0.5, 0.5, 0.5)
+	hbox.add_child(status_dot)
+
+	# Username label
+	var name_label := Label.new()
+	name_label.text = uname
+	name_label.size_flags_horizontal = Control.SIZE_EXPAND_FILL
+	hbox.add_child(name_label)
+
+	# Presence info
+	var pres_label := Label.new()
+	if is_online:
+		pres_label.text = "Online" + ((" - " + custom_status) if custom_status != "" else "")
+		pres_label.modulate = Color(0.3, 0.9, 0.3)
+	else:
+		pres_label.text = "Offline" + ((" (" + last_seen.left(10) + ")") if last_seen != "" else "")
+		pres_label.modulate = Color(0.6, 0.6, 0.6)
+	pres_label.size_flags_horizontal = Control.SIZE_EXPAND_FILL
+	hbox.add_child(pres_label)
+
+	# Action: Unfriend
+	var unfriend_btn := Button.new()
+	unfriend_btn.text = "Unfriend"
+	unfriend_btn.pressed.connect(func(): _on_unfriend(uid))
+	hbox.add_child(unfriend_btn)
+
+	# Action: Block
+	var block_btn := Button.new()
+	block_btn.text = "Block"
+	block_btn.pressed.connect(func(): _on_block_friend(uid))
+	hbox.add_child(block_btn)
+
+	friends_container.add_child(hbox)
+
+
+func _on_unfriend(uid: int) -> void:
+	var res: Dictionary = await _api_client.unfriend(uid)
+	if res.ok:
+		show_message("Unfriended user.")
+		refresh_friends()
+	else:
+		show_message("Failed to unfriend: " + res.detail, true)
+
+
+func _on_block_friend(uid: int) -> void:
+	var res: Dictionary = await _api_client.block_user(uid)
+	if res.ok:
+		show_message("Blocked user.")
+		refresh_friends()
+		refresh_blocked()
+	else:
+		show_message("Failed to block user: " + res.detail, true)
+
+
+func _on_presence_changed(uid: int, p_status: String) -> void:
+	if not _friend_presence_map.has(uid):
+		_friend_presence_map[uid] = {}
+	_friend_presence_map[uid]["status"] = p_status
+	# Refresh UI if row exists
+	var row_name := "FriendRow_%d" % uid
+	if friends_container.has_node(row_name):
+		refresh_friends()
+
+
+func _on_set_status_pressed() -> void:
+	if _api_client == null:
+		return
+	var new_status := custom_status_input.text.strip_edges()
+	var res: Dictionary = await _api_client.send_presence_heartbeat(new_status)
+	if res.ok:
+		show_message("Status updated.")
+	else:
+		show_message("Failed to update status: " + res.detail, true)
+
+
+# ── Requests ──
+
+func refresh_requests() -> void:
+	if _api_client == null:
+		return
+	var res: Dictionary = await _api_client.get_friend_requests()
+	_clear_children(requests_container)
+
+	if not res.ok:
+		show_message("Failed to load requests: " + res.detail, true)
+		return
+
+	var req_list: Array = []
+	if res.data is Dictionary and res.data.has("requests"):
+		req_list = res.data["requests"]
+
+	if req_list.is_empty():
+		var empty_label := Label.new()
+		empty_label.text = "No pending friend requests."
+		empty_label.modulate = Color(0.7, 0.7, 0.7)
+		requests_container.add_child(empty_label)
+		return
+
+	for req in req_list:
+		var req_id: int = int(req.get("id", 0))
+		var from_id: int = int(req.get("requester_id", 0))
+		var created_at: String = str(req.get("created_at", "")).left(10)
+
+		var hbox := HBoxContainer.new()
+		hbox.add_theme_constant_override("separation", 12)
+
+		var lbl := Label.new()
+		lbl.text = "Request from User #%d (%s)" % [from_id, created_at]
+		lbl.size_flags_horizontal = Control.SIZE_EXPAND_FILL
+		hbox.add_child(lbl)
+
+		var accept_btn := Button.new()
+		accept_btn.text = "Accept"
+		accept_btn.pressed.connect(func(): _on_accept_request(req_id))
+		hbox.add_child(accept_btn)
+
+		var decline_btn := Button.new()
+		decline_btn.text = "Decline"
+		decline_btn.pressed.connect(func(): _on_decline_request(req_id))
+		hbox.add_child(decline_btn)
+
+		requests_container.add_child(hbox)
+
+
+func _on_accept_request(req_id: int) -> void:
+	var res: Dictionary = await _api_client.accept_friend_request(req_id)
+	if res.ok:
+		show_message("Friend request accepted!")
+		refresh_requests()
+		refresh_friends()
+	else:
+		show_message("Failed to accept: " + res.detail, true)
+
+
+func _on_decline_request(req_id: int) -> void:
+	var res: Dictionary = await _api_client.decline_friend_request(req_id)
+	if res.ok:
+		show_message("Friend request declined.")
+		refresh_requests()
+	else:
+		show_message("Failed to decline: " + res.detail, true)
+
+
+func _on_send_req_pressed() -> void:
+	var target_text := send_req_input.text.strip_edges()
+	if not target_text.is_valid_int():
+		show_message("Enter a valid integer user ID.", true)
+		return
+	var target_id := int(target_text)
+	var res: Dictionary = await _api_client.send_friend_request(target_id)
+	if res.ok:
+		show_message("Friend request sent to User #%d!" % target_id)
+		send_req_input.text = ""
+	else:
+		show_message("Failed to send request: " + res.detail, true)
+
+
+# ── Following ──
+
+func refresh_following() -> void:
+	if _api_client == null:
+		return
+	var res: Dictionary = await _api_client.get_following()
+	_clear_children(following_container)
+
+	if not res.ok:
+		return
+
+	var list: Array = []
+	if res.data is Dictionary and res.data.has("following"):
+		list = res.data["following"]
+
+	if list.is_empty():
+		var empty_label := Label.new()
+		empty_label.text = "You are not following anyone."
+		empty_label.modulate = Color(0.7, 0.7, 0.7)
+		following_container.add_child(empty_label)
+		return
+
+	for u in list:
+		var uid: int = int(u.get("id", 0))
+		var uname: String = str(u.get("username", "Unknown"))
+
+		var hbox := HBoxContainer.new()
+		hbox.add_theme_constant_override("separation", 12)
+
+		var lbl := Label.new()
+		lbl.text = "%s (ID: %d)" % [uname, uid]
+		lbl.size_flags_horizontal = Control.SIZE_EXPAND_FILL
+		hbox.add_child(lbl)
+
+		var unfollow_btn := Button.new()
+		unfollow_btn.text = "Unfollow"
+		unfollow_btn.pressed.connect(func(): _on_unfollow(uid))
+		hbox.add_child(unfollow_btn)
+
+		following_container.add_child(hbox)
+
+
+func _on_unfollow(uid: int) -> void:
+	var res: Dictionary = await _api_client.unfollow_user(uid)
+	if res.ok:
+		show_message("Unfollowed User #%d." % uid)
+		refresh_following()
+	else:
+		show_message("Failed to unfollow: " + res.detail, true)
+
+
+func _on_follow_pressed() -> void:
+	var target_text := follow_input.text.strip_edges()
+	if not target_text.is_valid_int():
+		show_message("Enter a valid integer user ID.", true)
+		return
+	var target_id := int(target_text)
+	var res: Dictionary = await _api_client.follow_user(target_id)
+	if res.ok:
+		show_message("Following User #%d." % target_id)
+		follow_input.text = ""
+		refresh_following()
+	else:
+		show_message("Failed to follow: " + res.detail, true)
+
+
+# ── Blocked ──
+
+func refresh_blocked() -> void:
+	if _api_client == null:
+		return
+	var res: Dictionary = await _api_client.get_blocked()
+	_clear_children(blocked_container)
+
+	if not res.ok:
+		return
+
+	var list: Array = []
+	if res.data is Dictionary and res.data.has("blocked"):
+		list = res.data["blocked"]
+
+	if list.is_empty():
+		var empty_label := Label.new()
+		empty_label.text = "No blocked users."
+		empty_label.modulate = Color(0.7, 0.7, 0.7)
+		blocked_container.add_child(empty_label)
+		return
+
+	for u in list:
+		var uid: int = int(u.get("id", 0))
+		var uname: String = str(u.get("username", "Unknown"))
+
+		var hbox := HBoxContainer.new()
+		hbox.add_theme_constant_override("separation", 12)
+
+		var lbl := Label.new()
+		lbl.text = "%s (ID: %d)" % [uname, uid]
+		lbl.size_flags_horizontal = Control.SIZE_EXPAND_FILL
+		hbox.add_child(lbl)
+
+		var unblock_btn := Button.new()
+		unblock_btn.text = "Unblock"
+		unblock_btn.pressed.connect(func(): _on_unblock(uid))
+		hbox.add_child(unblock_btn)
+
+		blocked_container.add_child(hbox)
+
+
+func _on_unblock(uid: int) -> void:
+	var res: Dictionary = await _api_client.unblock_user(uid)
+	if res.ok:
+		show_message("Unblocked User #%d." % uid)
+		refresh_blocked()
+	else:
+		show_message("Failed to unblock: " + res.detail, true)
+
+
+func _on_block_pressed() -> void:
+	var target_text := block_input.text.strip_edges()
+	if not target_text.is_valid_int():
+		show_message("Enter a valid integer user ID.", true)
+		return
+	var target_id := int(target_text)
+	var res: Dictionary = await _api_client.block_user(target_id)
+	if res.ok:
+		show_message("Blocked User #%d." % target_id)
+		block_input.text = ""
+		refresh_blocked()
+		refresh_friends()
+	else:
+		show_message("Failed to block: " + res.detail, true)
+
+
+func _clear_children(node: Node) -> void:
+	if node == null:
+		return
+	for c in node.get_children():
+		c.queue_free()

scripts/game.gd

@@ -28,23 +28,150 @@ var _remotes: Dictionary = {}   # peer_id -> Node3D
 var _remote_prev: Dictionary = {}   # peer_id -> Vector3 (last snapshot position)
 var _status_label: Label = null
 
+## Build-mode UI, gated behind toggle_build_mode (F2) -- only ever
+## instantiated once the player actually enters build mode
+## (docs/architecture/editor.md §7.2: "Instantiated only when the player
+## enters 'build mode'... so the runtime footprint is negligible during
+## normal play"). Editing is in-memory only here; the save path to the
+## backend is a sibling task (world_persistence_impl.md).
+var _build_editor: InGameEditor = null
+
 
 func _ready() -> void:
 	_show_build_stamp()
-	if Session.active:
+	if Session.editing:
+		_open_editor_for_world()
+	elif Session.active:
 		_setup_networked()
 
 
 func _unhandled_input(event: InputEvent) -> void:
-	# ESC leaves the world back to the browser. Handled here (the scene root
+	if event.is_action_pressed("toggle_build_mode"):
+		# world_persistence_impl.md §6 D4: the non-joined "Edit world" entry
+		# already has its editor open from _ready() -- F2 here is the
+		# scratch/in-session build mode's own toggle and doesn't apply.
+		if not Session.editing:
+			get_viewport().set_input_as_handled()
+			_toggle_build_mode()
+		return
+
+	# ESC leaves the world back to the browser (or, while build mode is
+	# open, just closes build mode instead). Handled here (the scene root
 	# that owns the connection) rather than in player.gd so the teardown is
 	# a single ordered path -- doing it from two places raced _on_server_lost
 	# against the scene change and looked like a crash.
 	if event.is_action_pressed("ui_cancel"):
 		get_viewport().set_input_as_handled()
+		if Session.editing:
+			# Non-joined editing has no play session to fall back into --
+			# closing it means leaving, same as the Close button.
+			_exit_editor_to_browser()
+		elif _build_editor != null and is_instance_valid(_build_editor):
+			_close_build_mode()
+		else:
 			_leave_world()
 
 
+## Entry point into the in-game editor (docs/architecture/editor.md §7.2).
+## Freezes the player and opens a fresh, empty in-memory chunk to edit --
+## loading a *real* chunk from the backend for editing is the sibling
+## save-path task's territory (it owns the HTTP round-trip); this task's
+## contract stops at "a correctly-editable in-memory ChunkEditorModel".
+func _toggle_build_mode() -> void:
+	if _build_editor != null and is_instance_valid(_build_editor):
+		_close_build_mode()
+	else:
+		_open_build_mode()
+
+
+func _open_build_mode() -> void:
+	var model := ChunkEditorModel.create_empty(32, 32, str(Session.world_id), "main")
+	var catalog := EditorObjectCatalog.new()
+	var err := catalog.load_catalog()
+	if err != OK:
+		push_error("game.gd: failed to load editor object catalog (%d)" % err)
+	var core := EditorCore.new(model, catalog)
+
+	_build_editor = InGameEditor.new(core)
+	_build_editor.closed.connect(_close_build_mode)
+	add_child(_build_editor)
+
+	Input.mouse_mode = Input.MOUSE_MODE_VISIBLE
+	_player.set_physics_process(false)
+	_player.set_process_unhandled_input(false)
+
+
+## Shared teardown for both close paths (F2 again, or the editor's own
+## Close button/`closed` signal) -- safe to call twice: `queue_free()` on an
+## already-freeing node and restoring already-restored player state are
+## both no-ops.
+func _close_build_mode() -> void:
+	if _build_editor != null and is_instance_valid(_build_editor):
+		_build_editor.queue_free()
+	_build_editor = null
+	_player.set_physics_process(true)
+	_player.set_process_unhandled_input(true)
+	_player._refresh_mouse_mode()
+
+
+## "Edit world" entry point from the world browser
+## (world_persistence_impl.md §6 D4 / §9 "Client/editor task"). Reached only
+## via Session.editing (set by world_list.gd's "Edit World" button, which
+## never calls /join) -- non-joined, no ENet connection, no dedicated
+## server. Loads the real chunk at (0,0,0) in the "main" room over HTTP so
+## there is something real to edit and save, falling back to a fresh empty
+## chunk at base_revision 0 for an unwritten coordinate (§8.1: "an unwritten
+## coordinate is not an error").
+func _open_editor_for_world() -> void:
+	Input.mouse_mode = Input.MOUSE_MODE_VISIBLE
+	_player.set_physics_process(false)
+	_player.set_process_unhandled_input(false)
+
+	var world_id_str := str(Session.world_id)
+	var room_slug := "main"
+	var coord := Vector3i.ZERO
+
+	var save_service := ChunkSaveService.new()
+	save_service.world_id = world_id_str
+	save_service.room_slug = room_slug
+	add_child(save_service)
+
+	var fetch_result: Dictionary = await save_service.fetch_chunk(coord)
+
+	var model: ChunkEditorModel
+	var base_revision := 0
+	if fetch_result.get("ok", false) and fetch_result.get("model") != null:
+		model = fetch_result["model"]
+		base_revision = int(fetch_result.get("revision", 0))
+	else:
+		if not fetch_result.get("ok", false):
+			push_error("game.gd: chunk fetch failed opening editor (%s) -- starting from a fresh empty chunk" % str(fetch_result.get("detail", "")))
+		model = ChunkEditorModel.create_empty(32, 32, world_id_str, room_slug, coord)
+		base_revision = 0
+
+	var catalog := EditorObjectCatalog.new()
+	var err := catalog.load_catalog()
+	if err != OK:
+		push_error("game.gd: failed to load editor object catalog (%d)" % err)
+	var core := EditorCore.new(model, catalog)
+
+	_build_editor = InGameEditor.new(core)
+	_build_editor.setup_persistence(save_service, world_id_str, room_slug, coord, base_revision)
+	_build_editor.closed.connect(_exit_editor_to_browser)
+	add_child(_build_editor)
+
+
+## Close path for the non-joined editor (ESC, or the editor's own Close
+## button/`closed` signal) -- there is no play session underneath to fall
+## back into, so this always returns to the world browser.
+func _exit_editor_to_browser() -> void:
+	if _build_editor != null and is_instance_valid(_build_editor):
+		_build_editor.queue_free()
+	_build_editor = null
+	Session.clear()
+	get_tree().change_scene_to_file("res://scenes/world_list.tscn")
+
+
 func _leave_world() -> void:
 	if _leaving:
 		return

scripts/groups_ui.gd

@@ -0,0 +1,357 @@
+extends Control
+class_name GroupsUI
+## Groups & Communities UI.
+##
+## Features:
+## - Browse groups with pagination and "My Groups" filter
+## - Create new group (creator becomes owner)
+## - Detailed group page: description, member count, member list with roles
+## - Join and Leave group actions
+## - Role management for owner (promote to admin, demote to member, transfer ownership)
+## - Delete group (owner only)
+
+signal back_requested
+
+@onready var back_button: Button = $VBoxContainer/HeaderHBox/BackButton
+@onready var title_label: Label = $VBoxContainer/HeaderHBox/TitleLabel
+@onready var refresh_button: Button = $VBoxContainer/HeaderHBox/RefreshButton
+@onready var status_label: Label = $VBoxContainer/StatusMessageLabel
+
+@onready var tab_container: TabContainer = $VBoxContainer/TabContainer
+
+# Browse controls
+@onready var my_groups_check: CheckBox = $VBoxContainer/TabContainer/Browse/FilterHBox/MyGroupsCheck
+@onready var groups_list_container: VBoxContainer = $VBoxContainer/TabContainer/Browse/Scroll/GroupsList
+
+# Create controls
+@onready var new_group_name_edit: LineEdit = $VBoxContainer/TabContainer/Create/FormVBox/NameEdit
+@onready var new_group_desc_edit: TextEdit = $VBoxContainer/TabContainer/Create/FormVBox/DescEdit
+@onready var create_group_btn: Button = $VBoxContainer/TabContainer/Create/FormVBox/CreateButton
+
+# Group Page controls
+@onready var group_page_vbox: VBoxContainer = $VBoxContainer/TabContainer/GroupDetails/Scroll/DetailsVBox
+@onready var group_name_label: Label = $VBoxContainer/TabContainer/GroupDetails/Scroll/DetailsVBox/HeaderHBox/GroupNameLabel
+@onready var member_count_label: Label = $VBoxContainer/TabContainer/GroupDetails/Scroll/DetailsVBox/HeaderHBox/MemberCountLabel
+@onready var group_desc_label: Label = $VBoxContainer/TabContainer/GroupDetails/Scroll/DetailsVBox/GroupDescLabel
+@onready var join_btn: Button = $VBoxContainer/TabContainer/GroupDetails/Scroll/DetailsVBox/ActionsHBox/JoinButton
+@onready var leave_btn: Button = $VBoxContainer/TabContainer/GroupDetails/Scroll/DetailsVBox/ActionsHBox/LeaveButton
+@onready var delete_btn: Button = $VBoxContainer/TabContainer/GroupDetails/Scroll/DetailsVBox/ActionsHBox/DeleteButton
+@onready var members_list_container: VBoxContainer = $VBoxContainer/TabContainer/GroupDetails/Scroll/DetailsVBox/MembersVBox/MembersList
+
+var _api_client: Node = null
+var _current_user_id: int = 0
+var _active_group_id: int = 0
+var _active_group_data: Dictionary = {}
+
+
+func _ready() -> void:
+	_api_client = _get_api()
+	_wire_signals()
+	if _api_client != null and _api_client.has_token():
+		_init_user()
+		refresh_groups()
+
+
+func _get_api() -> Node:
+	if has_node("/root/ApiClient"):
+		return get_node("/root/ApiClient")
+	return null
+
+
+func _init_user() -> void:
+	if _api_client == null:
+		return
+	var me_res: Dictionary = await _api_client.get_me()
+	if me_res.ok and me_res.data is Dictionary:
+		_current_user_id = int(me_res.data.get("id", 0))
+
+
+func _wire_signals() -> void:
+	if back_button:
+		back_button.pressed.connect(_on_back_pressed)
+	if refresh_button:
+		refresh_button.pressed.connect(refresh_groups)
+	if my_groups_check:
+		my_groups_check.toggled.connect(func(_t): refresh_groups())
+	if create_group_btn:
+		create_group_btn.pressed.connect(_on_create_group_pressed)
+	if join_btn:
+		join_btn.pressed.connect(_on_join_pressed)
+	if leave_btn:
+		leave_btn.pressed.connect(_on_leave_pressed)
+	if delete_btn:
+		delete_btn.pressed.connect(_on_delete_pressed)
+
+
+func _on_back_pressed() -> void:
+	back_requested.emit()
+	if get_tree().current_scene == self:
+		get_tree().change_scene_to_file("res://scenes/main_menu.tscn")
+
+
+func show_message(text: String, is_error: bool = false) -> void:
+	if status_label:
+		status_label.text = text
+		status_label.modulate = Color(1.0, 0.4, 0.4) if is_error else Color(0.4, 1.0, 0.4)
+
+
+# ── Browse Groups ──
+
+func refresh_groups() -> void:
+	if _api_client == null or not _api_client.has_token():
+		return
+	var mine: bool = my_groups_check.button_pressed if my_groups_check else false
+	var res: Dictionary = await _api_client.list_groups(1, 50, mine)
+	_clear_children(groups_list_container)
+
+	if not res.ok:
+		show_message("Failed to load groups: " + res.detail, true)
+		return
+
+	var groups: Array = []
+	if res.data is Dictionary and res.data.has("groups"):
+		groups = res.data["groups"]
+	elif res.data is Array:
+		groups = res.data
+
+	if groups.is_empty():
+		var empty_lbl := Label.new()
+		empty_lbl.text = "No groups found. Create one in the Create Group tab!"
+		empty_lbl.modulate = Color(0.6, 0.6, 0.6)
+		groups_list_container.add_child(empty_lbl)
+		return
+
+	for g in groups:
+		var gid: int = int(g.get("id", 0))
+		var gname: String = str(g.get("name", "Group"))
+		var gdesc: String = str(g.get("description", ""))
+		var count: int = int(g.get("member_count", 0))
+		_build_group_card(gid, gname, gdesc, count)
+
+
+func _build_group_card(gid: int, gname: String, gdesc: String, count: int) -> void:
+	var panel := PanelContainer.new()
+	var margin := MarginContainer.new()
+	margin.add_theme_constant_override("margin_left", 12)
+	margin.add_theme_constant_override("margin_top", 12)
+	margin.add_theme_constant_override("margin_right", 12)
+	margin.add_theme_constant_override("margin_bottom", 12)
+
+	var hbox := HBoxContainer.new()
+	hbox.add_theme_constant_override("separation", 16)
+
+	var info_vbox := VBoxContainer.new()
+	info_vbox.size_flags_horizontal = Control.SIZE_EXPAND_FILL
+
+	var name_lbl := Label.new()
+	name_lbl.text = gname
+	name_lbl.add_theme_font_size_override("font_size", 18)
+	info_vbox.add_child(name_lbl)
+
+	if gdesc != "":
+		var desc_lbl := Label.new()
+		desc_lbl.text = gdesc.left(100)
+		desc_lbl.modulate = Color(0.8, 0.8, 0.8)
+		info_vbox.add_child(desc_lbl)
+
+	var count_lbl := Label.new()
+	count_lbl.text = "%d member%s" % [count, "" if count == 1 else "s"]
+	count_lbl.modulate = Color(0.6, 0.8, 1.0)
+	info_vbox.add_child(count_lbl)
+
+	hbox.add_child(info_vbox)
+
+	var view_btn := Button.new()
+	view_btn.text = "View Group"
+	view_btn.custom_minimum_size = Vector2(110, 36)
+	view_btn.size_flags_vertical = Control.SIZE_SHRINK_CENTER
+	view_btn.pressed.connect(func(): open_group_page(gid))
+	hbox.add_child(view_btn)
+
+	margin.add_child(hbox)
+	panel.add_child(margin)
+	groups_list_container.add_child(panel)
+
+
+# ── Create Group ──
+
+func _on_create_group_pressed() -> void:
+	if _api_client == null:
+		return
+	var gname := new_group_name_edit.text.strip_edges()
+	var gdesc := new_group_desc_edit.text.strip_edges()
+	if gname == "":
+		show_message("Group name cannot be empty.", true)
+		return
+
+	var res: Dictionary = await _api_client.create_group(gname, gdesc)
+	if res.ok and res.data is Dictionary:
+		var gid: int = int(res.data.get("id", 0))
+		new_group_name_edit.text = ""
+		new_group_desc_edit.text = ""
+		show_message("Group '%s' created!" % gname)
+		await refresh_groups()
+		open_group_page(gid)
+	else:
+		show_message("Failed to create group: " + res.detail, true)
+
+
+# ── Group Page Details ──
+
+func open_group_page(group_id: int) -> void:
+	_active_group_id = group_id
+	if tab_container:
+		tab_container.current_tab = 2 # Details tab
+	await refresh_group_page(group_id)
+
+
+func refresh_group_page(group_id: int) -> void:
+	if _api_client == null or group_id <= 0:
+		return
+	var res: Dictionary = await _api_client.get_group(group_id)
+	if not res.ok:
+		show_message("Failed to load group: " + res.detail, true)
+		return
+
+	_active_group_data = res.data if res.data is Dictionary else {}
+	var gname: String = str(_active_group_data.get("name", "Group"))
+	var gdesc: String = str(_active_group_data.get("description", "No description provided."))
+	var members: Array = _active_group_data.get("members", [])
+	var count: int = int(_active_group_data.get("member_count", members.size()))
+	var owner_id: int = int(_active_group_data.get("owner_id", 0))
+
+	if group_name_label:
+		group_name_label.text = gname
+	if group_desc_label:
+		group_desc_label.text = gdesc
+	if member_count_label:
+		member_count_label.text = "%d Members" % count
+
+	# Check membership of current user
+	var is_member := false
+	var my_role := ""
+	for m in members:
+		var uid: int = int(m.get("user_id", 0))
+		if uid == _current_user_id:
+			is_member = true
+			my_role = str(m.get("role", "member"))
+			break
+
+	var is_owner := (_current_user_id == owner_id) or my_role == "owner"
+
+	if join_btn:
+		join_btn.visible = not is_member
+	if leave_btn:
+		leave_btn.visible = is_member and not is_owner
+	if delete_btn:
+		delete_btn.visible = is_owner
+
+	_populate_members_list(members, is_owner)
+
+
+func _populate_members_list(members: Array, can_manage_roles: bool) -> void:
+	_clear_children(members_list_container)
+
+	for m in members:
+		var uid: int = int(m.get("user_id", 0))
+		var uname: String = "User #%d" % uid
+		if m.has("user") and m["user"] is Dictionary:
+			uname = str(m["user"].get("username", uname))
+		var role: String = str(m.get("role", "member"))
+
+		var hbox := HBoxContainer.new()
+		hbox.add_theme_constant_override("separation", 12)
+
+		var name_lbl := Label.new()
+		name_lbl.text = "%s (ID: %d)" % [uname, uid]
+		name_lbl.size_flags_horizontal = Control.SIZE_EXPAND_FILL
+		hbox.add_child(name_lbl)
+
+		var role_badge := Label.new()
+		role_badge.text = "[%s]" % role.to_upper()
+		if role == "owner":
+			role_badge.modulate = Color(1.0, 0.8, 0.2)
+		elif role == "admin":
+			role_badge.modulate = Color(0.4, 0.8, 1.0)
+		else:
+			role_badge.modulate = Color(0.7, 0.7, 0.7)
+		hbox.add_child(role_badge)
+
+		# Role selector for owner (excluding self/owner)
+		if can_manage_roles and role != "owner":
+			var opt := OptionButton.new()
+			opt.add_item("Member")
+			opt.add_item("Admin")
+			opt.selected = 1 if role == "admin" else 0
+			opt.item_selected.connect(func(idx: int): _on_role_changed(uid, "admin" if idx == 1 else "member"))
+			hbox.add_child(opt)
+
+			var xfer_btn := Button.new()
+			xfer_btn.text = "Make Owner"
+			xfer_btn.pressed.connect(func(): _on_transfer_ownership(uid))
+			hbox.add_child(xfer_btn)
+
+		members_list_container.add_child(hbox)
+
+
+func _on_join_pressed() -> void:
+	if _api_client == null or _active_group_id <= 0:
+		return
+	var res: Dictionary = await _api_client.join_group(_active_group_id)
+	if res.ok:
+		show_message("Joined group!")
+		refresh_group_page(_active_group_id)
+	else:
+		show_message("Failed to join group: " + res.detail, true)
+
+
+func _on_leave_pressed() -> void:
+	if _api_client == null or _active_group_id <= 0:
+		return
+	var res: Dictionary = await _api_client.leave_group(_active_group_id)
+	if res.ok:
+		show_message("Left group.")
+		refresh_group_page(_active_group_id)
+	else:
+		show_message("Failed to leave group: " + res.detail, true)
+
+
+func _on_delete_pressed() -> void:
+	if _api_client == null or _active_group_id <= 0:
+		return
+	var res: Dictionary = await _api_client.delete_group(_active_group_id)
+	if res.ok:
+		show_message("Group deleted.")
+		tab_container.current_tab = 0
+		refresh_groups()
+	else:
+		show_message("Failed to delete group: " + res.detail, true)
+
+
+func _on_role_changed(uid: int, new_role: String) -> void:
+	if _api_client == null or _active_group_id <= 0:
+		return
+	var res: Dictionary = await _api_client.set_group_member_role(_active_group_id, uid, new_role)
+	if res.ok:
+		show_message("Role updated to %s." % new_role)
+		refresh_group_page(_active_group_id)
+	else:
+		show_message("Failed to change role: " + res.detail, true)
+
+
+func _on_transfer_ownership(new_owner_id: int) -> void:
+	if _api_client == null or _active_group_id <= 0:
+		return
+	var res: Dictionary = await _api_client.transfer_group_ownership(_active_group_id, new_owner_id)
+	if res.ok:
+		show_message("Ownership transferred to User #%d!" % new_owner_id)
+		refresh_group_page(_active_group_id)
+	else:
+		show_message("Failed to transfer ownership: " + res.detail, true)
+
+
+func _clear_children(node: Node) -> void:
+	if node == null:
+		return
+	for c in node.get_children():
+		c.queue_free()

scripts/http_chunk_source.gd

@@ -0,0 +1,203 @@
+class_name HttpChunkSource
+extends Node
+## HTTP-backed adapter for ChunkStreamManager.set_server_rpc().
+##
+## Implements docs/architecture/world_persistence_impl.md D6/§8.4: the
+## playing client streams chunks from the FastAPI backend over HTTP (the
+## same public routes the editor uses -- `backend/app/routers/world_content.py`),
+## not over the dedicated server's ENet connection.
+##
+## `ChunkStreamManager` only requires an object with a `request_chunk(key)`
+## method (see its `_server_rpc` seam); this adapter satisfies that and feeds
+## results back through the manager's existing (previously dormant)
+## `_on_chunk_data_received(key, bytes)` / `_on_chunk_load_error(coord, msg)`
+## methods, and its `_instantiate_chunk_scene(coord)` for the "unwritten
+## coordinate renders empty" case (§8.1).
+##
+## `ChunkStreamManager._load_chunk()` builds its request key with empty
+## world/room components (`Chunk.build_key("", "", coord)`) because the
+## manager itself has no notion of which world/room it's streaming --
+## that's this adapter's job. `request_chunk(key)` only reads the
+## coordinate out of the key it's given and rebuilds the real key from
+## `world_id`/`room_slug` before touching the network, per the doc's note
+## under §8.4.
+##
+## Must be added to the scene tree before use (it creates per-request
+## HTTPRequest child nodes), e.g.:
+##
+##     var source := HttpChunkSource.new()
+##     source.world_id = str(Session.world_id)
+##     source.room_slug = "main"
+##     source.stream_manager = stream_manager
+##     stream_manager.add_child(source)
+##     stream_manager.set_server_rpc(source)
+
+## The world this source fetches chunks for (string form of the backend's
+## numeric world id -- matches Chunk.build_key's world_id parameter type).
+var world_id: String = ""
+
+## The room slug within that world. world.md's default room is "main".
+var room_slug: String = "main"
+
+## The ChunkStreamManager to feed decoded results back into. Required.
+var stream_manager: ChunkStreamManager = null
+
+## In-memory ETag cache: chunk key -> last-known checksum (bare hex, no
+## quotes). Backs the on-disk payload cache so re-fetching an unchanged
+## chunk costs a 304, not a re-download (world_persistence_impl.md §8.1:
+## "This is what makes the client's user://chunk_cache/ cache cheap").
+var _etag_by_key: Dictionary = {}
+
+const CACHE_DIR := "user://chunk_cache"
+
+
+func _ready() -> void:
+	DirAccess.make_dir_recursive_absolute(CACHE_DIR)
+
+
+## Satisfies ChunkStreamManager's `_server_rpc.request_chunk(key)` seam.
+func request_chunk(key: String) -> void:
+	var coord: Variant = _coord_from_key(key)
+	if coord == null:
+		push_error("HttpChunkSource: malformed chunk key %s" % key)
+		return
+	_fetch(coord)
+
+
+## world_persistence_impl.md §8.1 chunk index -- lists which chunks in a
+## bounds actually exist without fetching their payloads. Not called by
+## ChunkStreamManager's per-coordinate streaming loop today, but is the
+## "bounds-query listing" half of this adapter's contract for future
+## callers (e.g. a minimap, or a smarter prefetcher).
+func list_chunks(cx_min: int, cx_max: int, cy_min: int, cy_max: int, cz: int = 0) -> Dictionary:
+	var path := "/api/worlds/%s/rooms/%s/chunks?cx_min=%d&cx_max=%d&cy_min=%d&cy_max=%d&cz=%d" % [
+		world_id, room_slug, cx_min, cx_max, cy_min, cy_max, cz
+	]
+	return await _api_client().request(HTTPClient.METHOD_GET, path, "", "application/json", true)
+
+
+# ─────────────────────────── internals ───────────────────────────
+
+## Resolved via an absolute node path rather than the bare `ApiClient`
+## autoload identifier: bare autoload identifiers only resolve at GDScript
+## compile time inside a scene the engine boots normally. Any script
+## compiled while running headless via `godot --script ...` (as
+## scripts/smoke_test_*.gd do) fails with "Identifier not found: ApiClient"
+## on the bare form -- confirmed while writing
+## scripts/smoke_test_http_chunk_source.gd. `get_node` resolves the same
+## singleton correctly in both contexts (the same pattern game.gd already
+## uses for AvatarSystem via `get_node_or_null("/root/AvatarSystem")`).
+func _api_client() -> Node:
+	return get_node("/root/ApiClient")
+
+
+func _fetch(coord: Vector3i) -> void:
+	var key := Chunk.build_key(world_id, room_slug, coord)
+
+	var http := HTTPRequest.new()
+	http.timeout = 10.0
+	add_child(http)
+
+	var api := _api_client()
+	var headers := PackedStringArray()
+	headers.append("Accept: application/octet-stream")
+	if api.has_token():
+		var bearer: String = api.bearer_token
+		headers.append("Authorization: " + bearer)
+	var cached_etag: String = _etag_by_key.get(key, "")
+	if cached_etag != "":
+		headers.append("If-None-Match: \"%s\"" % cached_etag)
+
+	var base_url: String = api.base_url
+	var url := "%s/api/worlds/%s/rooms/%s/chunks/%d/%d/%d" % [
+		base_url, world_id, room_slug, coord.x, coord.y, coord.z
+	]
+	var err := http.request(url, headers, HTTPClient.METHOD_GET)
+	if err != OK:
+		http.queue_free()
+		_fail(coord, "HttpChunkSource: failed to start request for %s (%d)" % [key, err])
+		return
+
+	var args: Array = await http.request_completed
+	var result_code: int = args[0]
+	var response_code: int = args[1]
+	var response_headers: PackedStringArray = args[2]
+	var body: PackedByteArray = args[3]
+	http.queue_free()
+
+	if result_code != HTTPRequest.RESULT_SUCCESS:
+		_fail(coord, "HttpChunkSource: transport error fetching %s (code %d)" % [key, result_code])
+		return
+
+	match response_code:
+		304:
+			var cached := _read_cache(cached_etag)
+			if cached.is_empty():
+				# Cache miss despite a 304 (e.g. the user:// cache got
+				# cleared) -- drop the stale ETag and refetch unconditionally
+				# rather than deliver empty bytes to the decoder.
+				_etag_by_key.erase(key)
+				_fetch(coord)
+				return
+			_deliver(key, cached)
+		200:
+			var checksum := _etag_from_headers(response_headers)
+			if checksum != "":
+				_etag_by_key[key] = checksum
+				_write_cache(checksum, body)
+			_deliver(key, body)
+		404:
+			# world_persistence_impl.md §8.1: "an unwritten coordinate is not
+			# an error to the streamer -- it renders empty."
+			if stream_manager != null:
+				stream_manager._instantiate_chunk_scene(coord)
+		_:
+			_fail(coord, "HttpChunkSource: HTTP %d fetching %s" % [response_code, key])
+
+
+func _deliver(key: String, bytes: PackedByteArray) -> void:
+	if stream_manager != null:
+		stream_manager._on_chunk_data_received(key, bytes)
+
+
+func _fail(coord: Vector3i, message: String) -> void:
+	push_error(message)
+	if stream_manager != null:
+		stream_manager._on_chunk_load_error(coord, message)
+
+
+func _coord_from_key(key: String) -> Variant:
+	var parts: PackedStringArray = key.split(":")
+	if parts.size() < 5:
+		return null
+	return Vector3i(int(parts[2]), int(parts[3]), int(parts[4]))
+
+
+func _etag_from_headers(headers: PackedStringArray) -> String:
+	for h in headers:
+		if h.to_lower().begins_with("etag:"):
+			var v := h.substr(h.find(":") + 1).strip_edges()
+			return v.trim_prefix('"').trim_suffix('"')
+	return ""
+
+
+func _cache_path(checksum: String) -> String:
+	return "%s/%s" % [CACHE_DIR, checksum]
+
+
+func _write_cache(checksum: String, bytes: PackedByteArray) -> void:
+	var f := FileAccess.open(_cache_path(checksum), FileAccess.WRITE)
+	if f:
+		f.store_buffer(bytes)
+		f.close()
+
+
+func _read_cache(checksum: String) -> PackedByteArray:
+	if checksum == "":
+		return PackedByteArray()
+	var f := FileAccess.open(_cache_path(checksum), FileAccess.READ)
+	if f == null:
+		return PackedByteArray()
+	var bytes := f.get_buffer(f.get_length())
+	f.close()
+	return bytes

scripts/profile_ui.gd

@@ -0,0 +1,312 @@
+extends Control
+class_name ProfileUI
+## Profile Page UI.
+##
+## Displays:
+## - User avatar representation, username, and bio
+## - Favorite experiences (worlds) list
+## - Public/mutual friends list
+## - Respects server-enforced privacy controls and blocked-user restricted view
+## - Allows authenticated user to edit their own bio and privacy settings
+
+signal back_requested
+
+@onready var back_button: Button = $VBoxContainer/HeaderHBox/BackButton
+@onready var title_label: Label = $VBoxContainer/HeaderHBox/TitleLabel
+@onready var refresh_button: Button = $VBoxContainer/HeaderHBox/RefreshButton
+@onready var status_label: Label = $VBoxContainer/StatusMessageLabel
+
+# Lookup controls
+@onready var user_id_edit: LineEdit = $VBoxContainer/LookupHBox/UserIdEdit
+@onready var view_user_btn: Button = $VBoxContainer/LookupHBox/ViewUserButton
+@onready var view_my_profile_btn: Button = $VBoxContainer/LookupHBox/ViewMyProfileButton
+
+# Profile Card details
+@onready var username_label: Label = $VBoxContainer/Scroll/ContentVBox/CardPanel/Margin/HBox/DetailsVBox/UsernameLabel
+@onready var user_id_label: Label = $VBoxContainer/Scroll/ContentVBox/CardPanel/Margin/HBox/DetailsVBox/UserIdLabel
+@onready var avatar_preview_label: Label = $VBoxContainer/Scroll/ContentVBox/CardPanel/Margin/HBox/AvatarBox/AvatarLabel
+@onready var bio_edit: TextEdit = $VBoxContainer/Scroll/ContentVBox/CardPanel/Margin/HBox/DetailsVBox/BioEdit
+@onready var save_bio_btn: Button = $VBoxContainer/Scroll/ContentVBox/CardPanel/Margin/HBox/DetailsVBox/SaveBioButton
+
+# Privacy Controls (visible only for own profile)
+@onready var privacy_vbox: VBoxContainer = $VBoxContainer/Scroll/ContentVBox/PrivacyVBox
+@onready var profile_vis_opt: OptionButton = $VBoxContainer/Scroll/ContentVBox/PrivacyVBox/Grid/ProfileVisOption
+@onready var friends_vis_opt: OptionButton = $VBoxContainer/Scroll/ContentVBox/PrivacyVBox/Grid/FriendsVisOption
+@onready var favorites_vis_opt: OptionButton = $VBoxContainer/Scroll/ContentVBox/PrivacyVBox/Grid/FavoritesVisOption
+@onready var save_privacy_btn: Button = $VBoxContainer/Scroll/ContentVBox/PrivacyVBox/SavePrivacyButton
+
+# Favorites list
+@onready var favorites_container: VBoxContainer = $VBoxContainer/Scroll/ContentVBox/FavoritesVBox/FavoritesList
+@onready var favorites_status_label: Label = $VBoxContainer/Scroll/ContentVBox/FavoritesVBox/FavoritesStatusLabel
+
+# Friends list
+@onready var friends_container: VBoxContainer = $VBoxContainer/Scroll/ContentVBox/FriendsVBox/FriendsList
+@onready var friends_status_label: Label = $VBoxContainer/Scroll/ContentVBox/FriendsVBox/FriendsStatusLabel
+
+var _api_client: Node = null
+var _viewing_user_id: int = 0
+var _my_user_id: int = 0
+var _is_own_profile: bool = false
+
+
+func _ready() -> void:
+	_api_client = _get_api()
+	_setup_privacy_options()
+	_wire_signals()
+
+	if _api_client != null and _api_client.has_token():
+		_init_my_profile()
+
+
+func _get_api() -> Node:
+	if has_node("/root/ApiClient"):
+		return get_node("/root/ApiClient")
+	return null
+
+
+func _setup_privacy_options() -> void:
+	var visibilities := ["public", "friends_only", "private"]
+	for opt in [profile_vis_opt, friends_vis_opt, favorites_vis_opt]:
+		if opt:
+			opt.clear()
+			for v in visibilities:
+				opt.add_item(v.capitalize())
+
+
+func _wire_signals() -> void:
+	if back_button:
+		back_button.pressed.connect(_on_back_pressed)
+	if refresh_button:
+		refresh_button.pressed.connect(_refresh_current)
+	if view_user_btn:
+		view_user_btn.pressed.connect(_on_view_user_pressed)
+	if view_my_profile_btn:
+		view_my_profile_btn.pressed.connect(_init_my_profile)
+	if save_bio_btn:
+		save_bio_btn.pressed.connect(_on_save_bio_pressed)
+	if save_privacy_btn:
+		save_privacy_btn.pressed.connect(_on_save_privacy_pressed)
+
+
+func _on_back_pressed() -> void:
+	back_requested.emit()
+	if get_tree().current_scene == self:
+		get_tree().change_scene_to_file("res://scenes/main_menu.tscn")
+
+
+func show_message(text: String, is_error: bool = false) -> void:
+	if status_label:
+		status_label.text = text
+		status_label.modulate = Color(1.0, 0.4, 0.4) if is_error else Color(0.4, 1.0, 0.4)
+
+
+func _init_my_profile() -> void:
+	if _api_client == null or not _api_client.has_token():
+		show_message("Log in to view profile.", true)
+		return
+
+	var me_res: Dictionary = await _api_client.get_me()
+	if me_res.ok and me_res.data is Dictionary:
+		_my_user_id = int(me_res.data.get("id", 0))
+		load_profile(_my_user_id, true)
+
+
+func _on_view_user_pressed() -> void:
+	var uid_str := user_id_edit.text.strip_edges()
+	if not uid_str.is_valid_int():
+		show_message("Enter a valid integer user ID.", true)
+		return
+	var uid := int(uid_str)
+	load_profile(uid, uid == _my_user_id)
+
+
+func _refresh_current() -> void:
+	if _viewing_user_id > 0:
+		load_profile(_viewing_user_id, _is_own_profile)
+
+
+## Load profile for user_id.
+func load_profile(user_id: int, is_own: bool = false) -> void:
+	_viewing_user_id = user_id
+	_is_own_profile = is_own
+
+	if _is_own_profile:
+		await _load_own_profile()
+	else:
+		await _load_public_profile(user_id)
+
+
+func _load_own_profile() -> void:
+	title_label.text = "My Profile"
+	if privacy_vbox:
+		privacy_vbox.visible = true
+	if save_bio_btn:
+		save_bio_btn.visible = true
+	if bio_edit:
+		bio_edit.editable = true
+
+	var res: Dictionary = await _api_client.get_my_profile()
+	if not res.ok:
+		show_message("Failed to load own profile: " + res.detail, true)
+		return
+
+	var data: Dictionary = res.data if res.data is Dictionary else {}
+	_populate_card(_my_user_id, "You", str(data.get("bio", "")), data.get("avatar_asset_id"))
+
+	# Privacy
+	if data.has("privacy_json") and data["privacy_json"] is Dictionary:
+		var priv: Dictionary = data["privacy_json"]
+		_set_option_val(profile_vis_opt, priv.get("profile_visibility", "public"))
+		_set_option_val(friends_vis_opt, priv.get("friends_list_visibility", "public"))
+		_set_option_val(favorites_vis_opt, priv.get("favorites_visibility", "public"))
+
+	# Load own favorites
+	var fav_res: Dictionary = await _api_client.get_my_favorites()
+	_populate_favorites(fav_res.data.get("world_ids", []) if fav_res.ok and fav_res.data is Dictionary else [])
+
+	# Load own friends
+	var fr_res: Dictionary = await _api_client.get_friends()
+	_populate_friends(fr_res.data.get("friends", []) if fr_res.ok and fr_res.data is Dictionary else [])
+
+
+func _load_public_profile(user_id: int) -> void:
+	title_label.text = "User Profile"
+	if privacy_vbox:
+		privacy_vbox.visible = false
+	if save_bio_btn:
+		save_bio_btn.visible = false
+	if bio_edit:
+		bio_edit.editable = false
+
+	var res: Dictionary = await _api_client.get_public_profile(user_id)
+	if not res.ok:
+		show_message("Failed to load profile: " + res.detail, true)
+		return
+
+	var data: Dictionary = res.data if res.data is Dictionary else {}
+	var uname: String = str(data.get("username", "User #%d" % user_id))
+	var bio: String = str(data.get("bio", "")) if data.get("bio") != null else "[Bio hidden or empty]"
+
+	_populate_card(user_id, uname, bio, data.get("avatar_asset_id"))
+
+	# Favorites
+	if data.has("favorites") and data["favorites"] != null:
+		_populate_favorites(data["favorites"])
+	else:
+		_clear_children(favorites_container)
+		if favorites_status_label:
+			favorites_status_label.text = "Favorites are hidden by privacy settings."
+			favorites_status_label.visible = true
+
+	# Friends
+	if data.has("friends") and data["friends"] != null:
+		_populate_friends(data["friends"])
+	else:
+		_clear_children(friends_container)
+		if friends_status_label:
+			friends_status_label.text = "Friends list is hidden by privacy settings."
+			friends_status_label.visible = true
+
+
+func _populate_card(uid: int, uname: String, bio: String, avatar_asset_id: Variant) -> void:
+	if username_label:
+		username_label.text = uname
+	if user_id_label:
+		user_id_label.text = "User ID: %d" % uid
+	if bio_edit:
+		bio_edit.text = bio
+	if avatar_preview_label:
+		avatar_preview_label.text = "Avatar #%s" % str(avatar_asset_id) if avatar_asset_id != null else "Default Avatar"
+
+
+func _populate_favorites(favorites: Array) -> void:
+	_clear_children(favorites_container)
+	if favorites_status_label:
+		favorites_status_label.visible = favorites.is_empty()
+		if favorites.is_empty():
+			favorites_status_label.text = "No favorite experiences yet."
+
+	for item in favorites:
+		var hbox := HBoxContainer.new()
+		hbox.add_theme_constant_override("separation", 8)
+		var lbl := Label.new()
+		if item is Dictionary:
+			lbl.text = "★ %s (World #%s)" % [str(item.get("name", "World")), str(item.get("id", ""))]
+		else:
+			lbl.text = "★ World #%s" % str(item)
+		hbox.add_child(lbl)
+		favorites_container.add_child(hbox)
+
+
+func _populate_friends(friends: Array) -> void:
+	_clear_children(friends_container)
+	if friends_status_label:
+		friends_status_label.visible = friends.is_empty()
+		if friends.is_empty():
+			friends_status_label.text = "No friends listed."
+
+	for friend in friends:
+		var hbox := HBoxContainer.new()
+		hbox.add_theme_constant_override("separation", 8)
+		var lbl := Label.new()
+		if friend is Dictionary:
+			var fid: int = int(friend.get("id", 0))
+			var fname: String = str(friend.get("username", "User"))
+			lbl.text = "👤 %s (ID: %d)" % [fname, fid]
+			hbox.add_child(lbl)
+			var view_btn := Button.new()
+			view_btn.text = "View"
+			view_btn.pressed.connect(func(): load_profile(fid, fid == _my_user_id))
+			hbox.add_child(view_btn)
+		else:
+			lbl.text = "👤 User #%s" % str(friend)
+			hbox.add_child(lbl)
+		friends_container.add_child(hbox)
+
+
+func _on_save_bio_pressed() -> void:
+	if _api_client == null or not _is_own_profile:
+		return
+	var new_bio := bio_edit.text.strip_edges() if bio_edit else ""
+	var res: Dictionary = await _api_client.update_my_profile(new_bio)
+	if res.ok:
+		show_message("Bio updated successfully!")
+	else:
+		show_message("Failed to update bio: " + res.detail, true)
+
+
+func _on_save_privacy_pressed() -> void:
+	if _api_client == null or not _is_own_profile:
+		return
+	var privacy := {
+		"profile_visibility": _get_option_val(profile_vis_opt),
+		"friends_list_visibility": _get_option_val(friends_vis_opt),
+		"favorites_visibility": _get_option_val(favorites_vis_opt),
+	}
+	var res: Dictionary = await _api_client.update_my_profile(null, null, privacy)
+	if res.ok:
+		show_message("Privacy settings updated!")
+	else:
+		show_message("Failed to update privacy: " + res.detail, true)
+
+
+func _set_option_val(opt: OptionButton, val: String) -> void:
+	if opt == null:
+		return
+	for i in range(opt.item_count):
+		if opt.get_item_text(i).to_lower() == val.to_lower():
+			opt.selected = i
+			return
+
+
+func _get_option_val(opt: OptionButton) -> String:
+	if opt == null or opt.selected < 0:
+		return "public"
+	return opt.get_item_text(opt.selected).to_lower().replace(" ", "_")
+
+
+func _clear_children(node: Node) -> void:
+	if node == null:
+		return
+	for c in node.get_children():
+		c.queue_free()

scripts/scripting/player_inventory.gd

@@ -0,0 +1,41 @@
+class_name PlayerInventory
+extends Node
+## Minimal per-player item-count store.
+##
+## docs/architecture/dynamic_object_node.gd's header notes that a dynamic
+## object's runtime state ("position, health, inventory") belongs to "the
+## entity system" -- but no such system exists yet (M9 Economy hasn't been
+## built). This is a deliberately small, local stub scoped to make
+## ScriptBehavior's `give_item` verb demonstrable now, not an attempt to
+## build the real economy/inventory system. Replace it wholesale when M9
+## lands; keep the give_item/get_count surface so existing ScriptBehavior
+## data keeps working against the real thing.
+##
+## Attach one of these as a child node named "Inventory" under a player (see
+## scenes/player.tscn) -- [ScriptInterpreterNode] looks it up by that name
+## when resolving `target: "player"` for the `give_item` verb.
+
+## Emitted whenever an item's count changes, with the item's new total.
+signal item_changed(item_id: String, count: int)
+
+var _items: Dictionary = {}  # item_id (String) -> count (int)
+
+
+## Add (or, with a negative count, remove) units of an item. Counts never go
+## negative. `count == 0` is a no-op.
+func give_item(item_id: String, count: int) -> void:
+	if item_id.is_empty() or count == 0:
+		return
+	var new_count: int = maxi(0, int(_items.get(item_id, 0)) + count)
+	_items[item_id] = new_count
+	item_changed.emit(item_id, new_count)
+
+
+## Current count for an item (0 if never granted).
+func get_count(item_id: String) -> int:
+	return int(_items.get(item_id, 0))
+
+
+## A snapshot of the whole inventory (for UI/debugging/tests).
+func get_all() -> Dictionary:
+	return _items.duplicate()