WIP checkpoint: T1: Moderation data model + Alembic migration

backend/alembic/env.py

@@ -8,7 +8,7 @@ from sqlalchemy.ext.asyncio import create_async_engine
 
 from app.config import settings
 from app.database import Base
-from app.models import user, session, world, asset  # noqa: F401
+from app.models import user, session, world, asset, report, moderation_action, appeal  # noqa: F401
 
 # this is the Alembic Config object, which provides
 # access to the values within the .ini file in use.

backend/alembic/versions/0003_trust_safety.py

@@ -1,268 +0,0 @@
-"""add trust & safety columns and tables
-
-Revision ID: 0003_trust_safety
-Revises: 0002_add_date_of_birth_to_users
-Create Date: 2025-07-10 00:00:00.000000
-
-"""
-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 = "0003_trust_safety"
-down_revision: Union[str, None] = "0002_add_date_of_birth_to_users"
-branch_labels: Union[str, Sequence[str], None] = None
-depends_on: Union[str, Sequence[str], None] = None
-
-
-def upgrade() -> None:
-    """Add role/banned_until/suspended_until to users, and create
-    reports, moderation_actions, and appeals tables."""
-
-    # ── ENUM types ──────────────────────────────────────────────
-
-    role_enum = postgresql.ENUM("user", "moderator", "admin", name="role")
-    role_enum.create(op.get_bind(), checkfirst=True)
-
-    target_type_enum = postgresql.ENUM(
-        "user", "world", "asset", "chat_message", name="target_type"
-    )
-    target_type_enum.create(op.get_bind(), checkfirst=True)
-
-    reason_category_enum = postgresql.ENUM(
-        "harassment",
-        "hate_speech",
-        "sexual_content",
-        "violence",
-        "spam",
-        "self_harm",
-        "other",
-        name="reason_category",
-    )
-    reason_category_enum.create(op.get_bind(), checkfirst=True)
-
-    report_status_enum = postgresql.ENUM(
-        "open", "in_review", "resolved", "dismissed", name="report_status"
-    )
-    report_status_enum.create(op.get_bind(), checkfirst=True)
-
-    resolution_enum = postgresql.ENUM(
-        "action_taken",
-        "action_not_needed",
-        "duplicate",
-        "escalated",
-        name="resolution",
-    )
-    resolution_enum.create(op.get_bind(), checkfirst=True)
-
-    moderation_action_enum = postgresql.ENUM(
-        "warn", "suspend", "ban", "restrict", "remove", "restore",
-        name="moderation_action",
-    )
-    moderation_action_enum.create(op.get_bind(), checkfirst=True)
-
-    appeal_status_enum = postgresql.ENUM(
-        "pending", "approved", "rejected", name="appeal_status"
-    )
-    appeal_status_enum.create(op.get_bind(), checkfirst=True)
-
-    # ── users table changes ─────────────────────────────────────
-
-    op.add_column(
-        "users",
-        sa.Column(
-            "role",
-            role_enum,
-            nullable=False,
-            server_default="user",
-        ),
-    )
-    op.add_column(
-        "users",
-        sa.Column("banned_until", sa.DateTime(timezone=True), nullable=True),
-    )
-    op.add_column(
-        "users",
-        sa.Column("suspended_until", sa.DateTime(timezone=True), nullable=True),
-    )
-
-    # ── reports table ───────────────────────────────────────────
-
-    op.create_table(
-        "reports",
-        sa.Column("id", sa.BigInteger(), primary_key=True, autoincrement=True),
-        sa.Column(
-            "reporter_id", sa.Integer(), sa.ForeignKey("users.id", ondelete="CASCADE"), nullable=False
-        ),
-        sa.Column(
-            "target_type",
-            target_type_enum,
-            nullable=False,
-        ),
-        sa.Column("target_id", sa.String(length=64), nullable=False),
-        sa.Column(
-            "reason_category",
-            reason_category_enum,
-            nullable=False,
-        ),
-        sa.Column("details", sa.Text(), nullable=True),
-        sa.Column(
-            "status",
-            report_status_enum,
-            nullable=False,
-            server_default="open",
-        ),
-        sa.Column(
-            "resolved_by",
-            sa.Integer(),
-            sa.ForeignKey("users.id", ondelete="SET NULL"),
-            nullable=True,
-        ),
-        sa.Column(
-            "resolution",
-            resolution_enum,
-            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),
-            onupdate=sa.func.now(),
-            nullable=False,
-        ),
-        sa.Column("resolved_at", sa.DateTime(timezone=True), nullable=True),
-        sa.UniqueConstraint("reporter_id", "target_type", "target_id"),
-    )
-    op.create_index(op.f("ix_reports_id"), "reports", ["id"], unique=False)
-    op.create_index(op.f("ix_reports_reporter_id"), "reports", ["reporter_id"], unique=False)
-
-    # ── moderation_actions table ────────────────────────────────
-
-    op.create_table(
-        "moderation_actions",
-        sa.Column("id", sa.BigInteger(), primary_key=True, autoincrement=True),
-        sa.Column(
-            "moderator_id",
-            sa.Integer(),
-            sa.ForeignKey("users.id", ondelete="CASCADE"),
-            nullable=False,
-        ),
-        sa.Column(
-            "target_user_id",
-            sa.Integer(),
-            sa.ForeignKey("users.id", ondelete="SET NULL"),
-            nullable=True,
-        ),
-        sa.Column(
-            "target_type",
-            target_type_enum,
-            nullable=False,
-        ),
-        sa.Column("target_id", sa.String(length=64), nullable=False),
-        sa.Column(
-            "action",
-            moderation_action_enum,
-            nullable=False,
-        ),
-        sa.Column("reason", sa.Text(), nullable=False),
-        sa.Column(
-            "report_id",
-            sa.Integer(),
-            sa.ForeignKey("reports.id", ondelete="SET NULL"),
-            nullable=True,
-        ),
-        sa.Column("expires_at", sa.DateTime(timezone=True), nullable=True),
-        sa.Column("revoked_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(op.f("ix_moderation_actions_id"), "moderation_actions", ["id"], unique=False)
-    op.create_index(
-        op.f("ix_moderation_actions_moderator_id"),
-        "moderation_actions",
-        ["moderator_id"],
-        unique=False,
-    )
-
-    # ── appeals table ───────────────────────────────────────────
-
-    op.create_table(
-        "appeals",
-        sa.Column("id", sa.BigInteger(), primary_key=True, autoincrement=True),
-        sa.Column(
-            "moderation_action_id",
-            sa.Integer(),
-            sa.ForeignKey("moderation_actions.id", ondelete="CASCADE"),
-            nullable=False,
-        ),
-        sa.Column(
-            "user_id",
-            sa.Integer(),
-            sa.ForeignKey("users.id", ondelete="CASCADE"),
-            nullable=False,
-        ),
-        sa.Column("reason", sa.Text(), nullable=False),
-        sa.Column(
-            "status",
-            appeal_status_enum,
-            nullable=False,
-            server_default="pending",
-        ),
-        sa.Column(
-            "reviewed_by",
-            sa.Integer(),
-            sa.ForeignKey("users.id", ondelete="SET NULL"),
-            nullable=True,
-        ),
-        sa.Column("reviewed_at", sa.DateTime(timezone=True), nullable=True),
-        sa.Column(
-            "created_at",
-            sa.DateTime(timezone=True),
-            server_default=sa.func.now(),
-            nullable=False,
-        ),
-        sa.UniqueConstraint("moderation_action_id", "user_id"),
-    )
-    op.create_index(op.f("ix_appeals_id"), "appeals", ["id"], unique=False)
-    op.create_index(op.f("ix_appeals_user_id"), "appeals", ["user_id"], unique=False)
-
-
-def downgrade() -> None:
-    """Remove trust & safety tables and columns."""
-
-    op.drop_index(op.f("ix_appeals_user_id"), table_name="appeals")
-    op.drop_index(op.f("ix_appeals_id"), table_name="appeals")
-    op.drop_table("appeals")
-
-    op.drop_index(op.f("ix_moderation_actions_moderator_id"), table_name="moderation_actions")
-    op.drop_index(op.f("ix_moderation_actions_id"), table_name="moderation_actions")
-    op.drop_table("moderation_actions")
-
-    op.drop_index(op.f("ix_reports_reporter_id"), table_name="reports")
-    op.drop_index(op.f("ix_reports_id"), table_name="reports")
-    op.drop_table("reports")
-
-    op.drop_column("users", "suspended_until")
-    op.drop_column("users", "banned_until")
-    op.drop_column("users", "role")
-
-    # Drop ENUM types
-    postgresql.ENUM(name="appeal_status").drop(op.get_bind(), checkfirst=True)
-    postgresql.ENUM(name="moderation_action").drop(op.get_bind(), checkfirst=True)
-    postgresql.ENUM(name="resolution").drop(op.get_bind(), checkfirst=True)
-    postgresql.ENUM(name="report_status").drop(op.get_bind(), checkfirst=True)
-    postgresql.ENUM(name="reason_category").drop(op.get_bind(), checkfirst=True)
-    postgresql.ENUM(name="target_type").drop(op.get_bind(), checkfirst=True)
-    postgresql.ENUM(name="role").drop(op.get_bind(), checkfirst=True)

backend/app/models/__init__.py

@@ -2,6 +2,8 @@ from app.models.user import User
 from app.models.session import Session
 from app.models.world import World
 from app.models.asset import Asset
-from app.models.moderation import Report, ModerationAction, Appeal
+from app.models.report import Report
+from app.models.moderation_action import ModerationAction
+from app.models.appeal import Appeal
 
 __all__ = ["User", "Session", "World", "Asset", "Report", "ModerationAction", "Appeal"]

backend/app/models/appeal.py

@@ -0,0 +1,67 @@
+"""Appeal model for moderation actions."""
+
+from datetime import datetime
+from typing import Optional
+
+from sqlalchemy import (
+    Column,
+    Enum,
+    ForeignKey,
+    Integer,
+    String,
+    Text,
+    DateTime,
+    CheckConstraint,
+)
+from sqlalchemy.orm import relationship
+from sqlalchemy.sql import func
+
+from app.database import Base
+
+
+class Appeal(Base):
+    __tablename__ = "appeals"
+
+    id = Column(Integer, primary_key=True, index=True)
+    moderation_action_id = Column(
+        Integer,
+        ForeignKey("moderation_actions.id", ondelete="CASCADE"),
+        nullable=False,
+    )
+    user_id = Column(
+        Integer,
+        ForeignKey("users.id", ondelete="CASCADE"),
+        nullable=False,
+    )
+    reason = Column(Text, nullable=False)
+    status = Column(
+        Enum("pending", "approved", "rejected", name="appeal_status", create_type=False),
+        nullable=False,
+        default="pending",
+    )
+    reviewed_by = Column(
+        Integer,
+        ForeignKey("users.id", ondelete="SET NULL"),
+        nullable=True,
+    )
+    reviewed_at = Column(DateTime(timezone=True), nullable=True)
+    created_at = Column(
+        DateTime(timezone=True),
+        server_default=func.now(),
+        nullable=False,
+    )
+
+    # Relationships
+    moderation_action = relationship("ModerationAction", back_populates="appeals")
+    reviewer = relationship(
+        "User",
+        foreign_keys=[reviewed_by],
+        back_populates="reviewed_appeals",
+    )
+
+    __table_args__ = (
+        CheckConstraint(
+            "status IN ('pending', 'approved', 'rejected')",
+            name="check_appeal_status",
+        ),
+    )

backend/app/models/moderation.py

@@ -1,225 +0,0 @@
-"""Trust & Safety models: reports, moderation actions, and appeals."""
-
-from datetime import datetime
-from typing import Optional
-
-from sqlalchemy import (
-    CheckConstraint,
-    Column,
-    DateTime,
-    Enum,
-    ForeignKey,
-    Integer,
-    String,
-    Text,
-    UniqueConstraint,
-    func,
-)
-from sqlalchemy.dialects.postgresql import ENUM as PG_ENUM
-from sqlalchemy.orm import relationship
-
-from app.database import Base
-
-
-# ---------------------------------------------------------------------------
-# ENUM helpers — created explicitly in Alembic, not via SQLAlchemy create_type
-# ---------------------------------------------------------------------------
-
-_role_enum = PG_ENUM(
-    "user", "moderator", "admin",
-    name="user_role",
-    create_type=False,
-)
-
-_target_type_enum = PG_ENUM(
-    "user", "world", "asset", "chat_message",
-    name="target_type",
-    create_type=False,
-)
-
-_reason_category_enum = PG_ENUM(
-    "harassment", "hate_speech", "sexual_content", "violence",
-    "spam", "self_harm", "other",
-    name="reason_category",
-    create_type=False,
-)
-
-_report_status_enum = PG_ENUM(
-    "open", "in_review", "resolved", "dismissed",
-    name="report_status",
-    create_type=False,
-)
-
-_resolution_enum = PG_ENUM(
-    "action_taken", "action_not_needed", "duplicate", "escalated",
-    name="resolution",
-    create_type=False,
-)
-
-_moderation_action_enum = PG_ENUM(
-    "warn", "suspend", "ban", "restrict", "remove", "restore",
-    name="moderation_action",
-    create_type=False,
-)
-
-_appeal_status_enum = PG_ENUM(
-    "pending", "approved", "rejected",
-    name="appeal_status",
-    create_type=False,
-)
-
-
-class Report(Base):
-    """A user-submitted report about another entity."""
-
-    __tablename__ = "reports"
-
-    id = Column(Integer, primary_key=True, autoincrement=True)
-    reporter_id = Column(
-        Integer,
-        ForeignKey("users.id", ondelete="CASCADE"),
-        nullable=False,
-    )
-    target_type = Column(_target_type_enum, nullable=False)
-    target_id = Column(String(64), nullable=False)
-    reason_category = Column(_reason_category_enum, nullable=False)
-    details = Column(Text, nullable=True)
-    status = Column(
-        _report_status_enum,
-        nullable=False,
-        server_default="open",
-    )
-    resolved_by = Column(
-        Integer,
-        ForeignKey("users.id", ondelete="SET NULL"),
-        nullable=True,
-    )
-    resolution = Column(_resolution_enum, nullable=True)
-    created_at = Column(
-        DateTime(timezone=True),
-        server_default=func.now(),
-    )
-    updated_at = Column(
-        DateTime(timezone=True),
-        onupdate=func.now(),
-    )
-    resolved_at = Column(DateTime(timezone=True), nullable=True)
-
-    # Coalesce duplicate reports from the same reporter about the same target
-    __table_args__ = (
-        UniqueConstraint("reporter_id", "target_type", "target_id",
-                         name="uq_reporter_target"),
-    )
-
-    # Relationships
-    reporter = relationship("User", back_populates="reports",
-                            foreign_keys=[reporter_id])
-    resolved_by_user = relationship("User", back_populates="resolved_reports",
-                                    foreign_keys=[resolved_by])
-    moderation_actions = relationship(
-        "ModerationAction",
-        back_populates="report",
-        cascade="all, delete-orphan",
-    )
-    appeals = relationship(
-        "Appeal",
-        back_populates="report",
-        cascade="all, delete-orphan",
-    )
-
-
-class ModerationAction(Base):
-    """A moderation action taken against a target."""
-
-    __tablename__ = "moderation_actions"
-
-    id = Column(Integer, primary_key=True, autoincrement=True)
-    moderator_id = Column(
-        Integer,
-        ForeignKey("users.id", ondelete="CASCADE"),
-        nullable=False,
-    )
-    target_user_id = Column(
-        Integer,
-        ForeignKey("users.id", ondelete="SET NULL"),
-        nullable=True,
-    )
-    target_type = Column(_target_type_enum, nullable=False)
-    target_id = Column(String(64), nullable=False)
-    action = Column(_moderation_action_enum, nullable=False)
-    reason = Column(Text, nullable=False)
-    report_id = Column(
-        Integer,
-        ForeignKey("reports.id", ondelete="SET NULL"),
-        nullable=True,
-    )
-    expires_at = Column(DateTime(timezone=True), nullable=True)
-    revoked_at = Column(DateTime(timezone=True), nullable=True)
-    created_at = Column(
-        DateTime(timezone=True),
-        server_default=func.now(),
-    )
-
-    # Relationships
-    moderator = relationship("User", back_populates="moderation_actions",
-                             foreign_keys=[moderator_id])
-    target_user = relationship("User", back_populates="moderation_actions_target",
-                               foreign_keys=[target_user_id])
-    report = relationship(
-        "Report",
-        back_populates="moderation_actions",
-    )
-    appeals = relationship(
-        "Appeal",
-        back_populates="moderation_action",
-        cascade="all, delete-orphan",
-    )
-
-
-class Appeal(Base):
-    """An appeal against a moderation action."""
-
-    __tablename__ = "appeals"
-
-    id = Column(Integer, primary_key=True, autoincrement=True)
-    moderation_action_id = Column(
-        Integer,
-        ForeignKey("moderation_actions.id", ondelete="CASCADE"),
-        nullable=False,
-    )
-    user_id = Column(
-        Integer,
-        ForeignKey("users.id", ondelete="CASCADE"),
-        nullable=False,
-    )
-    reason = Column(Text, nullable=False)
-    status = Column(
-        _appeal_status_enum,
-        nullable=False,
-        server_default="pending",
-    )
-    reviewed_by = Column(
-        Integer,
-        ForeignKey("users.id", ondelete="SET NULL"),
-        nullable=True,
-    )
-    reviewed_at = Column(DateTime(timezone=True), nullable=True)
-    created_at = Column(
-        DateTime(timezone=True),
-        server_default=func.now(),
-    )
-
-    # Prevent duplicate open appeals per sanction
-    __table_args__ = (
-        UniqueConstraint("moderation_action_id", "user_id",
-                         name="uq_action_user_appeal"),
-    )
-
-    # Relationships
-    moderation_action = relationship(
-        "ModerationAction",
-        back_populates="appeals",
-    )
-    user = relationship("User", back_populates="appeals")
-    reviewed_by_user = relationship("User", back_populates="reviewed_appeals",
-                                    foreign_keys=[reviewed_by])

backend/app/models/moderation_action.py

@@ -0,0 +1,118 @@
+"""Moderation action model."""
+
+from datetime import datetime
+from enum import Enum as PyEnum
+from typing import Optional
+
+from sqlalchemy import (
+    Column,
+    Enum,
+    ForeignKey,
+    Integer,
+    String,
+    Text,
+    DateTime,
+    func,
+)
+from sqlalchemy.dialects.postgresql import TIMESTAMPTZ
+from sqlalchemy.orm import relationship
+
+from app.database import Base
+
+
+class TargetType(str, PyEnum):
+    """Type of entity being reported or moderated."""
+    USER = "user"
+    WORLD = "world"
+    ASSET = "asset"
+    CHAT_MESSAGE = "chat_message"
+
+
+class ReasonCategory(str, PyEnum):
+    """Category of report reason."""
+    HARASSMENT = "harassment"
+    HATE_SPEECH = "hate_speech"
+    SEXUAL_CONTENT = "sexual_content"
+    VIOLENCE = "violence"
+    SPAM = "spam"
+    SELF_HARM = "self_harm"
+    OTHER = "other"
+
+
+class ReportStatus(str, PyEnum):
+    """Status of a report."""
+    OPEN = "open"
+    IN_REVIEW = "in_review"
+    RESOLVED = "resolved"
+    DISMISSED = "dismissed"
+
+
+class Resolution(str, PyEnum):
+    """Resolution outcome of a report."""
+    ACTION_TAKEN = "action_taken"
+    NO_ACTION = "no_action"
+
+
+class ModerationActionType(str, PyEnum):
+    """Type of moderation action."""
+    WARN = "warn"
+    SUSPEND = "suspend"
+    BAN = "ban"
+    RESTRICT = "restrict"
+    REMOVE = "remove"
+    RESTORE = "restore"
+
+
+class ModerationAction(Base):
+    __tablename__ = "moderation_actions"
+
+    id = Column(Integer, primary_key=True, index=True)
+    moderator_id = Column(
+        Integer,
+        ForeignKey("users.id", ondelete="SET NULL"),
+        nullable=True,
+    )
+    target_user_id = Column(
+        Integer,
+        ForeignKey("users.id", ondelete="SET NULL"),
+        nullable=True,
+    )
+    target_type = Column(
+        Enum(TargetType, name="target_type_enum", create_type=False),
+        nullable=False,
+    )
+    target_id = Column(String(64), nullable=False)
+    action = Column(
+        Enum(ModerationActionType, name="moderation_action_type_enum", create_type=False),
+        nullable=False,
+    )
+    reason = Column(Text, nullable=True)
+    report_id = Column(
+        Integer,
+        ForeignKey("reports.id", ondelete="SET NULL"),
+        nullable=True,
+    )
+    expires_at = Column(TIMESTAMPTZ, nullable=True)
+    revoked_at = Column(TIMESTAMPTZ, nullable=True)
+    created_at = Column(
+        DateTime(timezone=True),
+        server_default=func.now(),
+    )
+
+    # Relationships
+    moderator = relationship(
+        "User",
+        foreign_keys=[moderator_id],
+        back_populates="moderation_actions_given",
+    )
+    target_user = relationship(
+        "User",
+        foreign_keys=[target_user_id],
+        back_populates="moderation_actions_received",
+    )
+    report = relationship("Report", back_populates="moderation_actions")
+    appeals = relationship(
+        "Appeal",
+        back_populates="moderation_action",
+        cascade="all, delete-orphan",
+    )

backend/app/models/report.py

@@ -0,0 +1,146 @@
+"""Report model for user-generated moderation reports."""
+
+from datetime import datetime
+from typing import Optional
+
+import sqlalchemy as sa
+from sqlalchemy import (
+    Column,
+    DateTime,
+    Enum,
+    ForeignKey,
+    Integer,
+    String,
+    Text,
+)
+from sqlalchemy.dialects.postgresql import TIMESTAMPTZ
+from sqlalchemy.orm import relationship
+
+from app.database import Base
+
+
+class ReportStatus:
+    """Valid statuses for a Report."""
+
+    OPEN = "open"
+    IN_REVIEW = "in_review"
+    RESOLVED = "resolved"
+    DISMISSED = "dismissed"
+
+
+class Resolution:
+    """Possible resolution outcomes for a Report."""
+
+    ACTION_TAKEN = "action_taken"
+    NO_ACTION = "no_action"
+
+
+class TargetType:
+    """Types of entities that can be reported."""
+
+    USER = "user"
+    WORLD = "world"
+    ASSET = "asset"
+    CHAT_MESSAGE = "chat_message"
+
+
+class ReasonCategory:
+    """Categories for why something was reported."""
+
+    HARASSMENT = "harassment"
+    HATE_SPEECH = "hate_speech"
+    SEXUAL_CONTENT = "sexual_content"
+    VIOLENCE = "violence"
+    SPAM = "spam"
+    SELF_HARM = "self_harm"
+    OTHER = "other"
+
+
+class Report(Base):
+    __tablename__ = "reports"
+
+    id = Column(Integer, primary_key=True, index=True)
+    reporter_id = Column(
+        Integer,
+        ForeignKey("users.id", ondelete="CASCADE"),
+        nullable=False,
+    )
+    target_type = Column(
+        Enum(
+            TargetType.USER,
+            TargetType.WORLD,
+            TargetType.ASSET,
+            TargetType.CHAT_MESSAGE,
+            name="target_type",
+            create_type=False,
+        ),
+        nullable=False,
+    )
+    target_id = Column(String(64), nullable=False)
+    reason_category = Column(
+        Enum(
+            ReasonCategory.HARASSMENT,
+            ReasonCategory.HATE_SPEECH,
+            ReasonCategory.SEXUAL_CONTENT,
+            ReasonCategory.VIOLENCE,
+            ReasonCategory.SPAM,
+            ReasonCategory.SELF_HARM,
+            ReasonCategory.OTHER,
+            name="reason_category",
+            create_type=False,
+        ),
+        nullable=False,
+    )
+    details = Column(Text, nullable=True)
+    status = Column(
+        Enum(
+            ReportStatus.OPEN,
+            ReportStatus.IN_REVIEW,
+            ReportStatus.RESOLVED,
+            ReportStatus.DISMISSED,
+            name="report_status",
+            create_type=False,
+        ),
+        nullable=False,
+        default=ReportStatus.OPEN,
+    )
+    resolved_by = Column(
+        Integer,
+        ForeignKey("users.id", ondelete="SET NULL"),
+        nullable=True,
+    )
+    resolution = Column(
+        Enum(
+            Resolution.ACTION_TAKEN,
+            Resolution.NO_ACTION,
+            name="resolution",
+            create_type=False,
+        ),
+        nullable=True,
+    )
+    created_at = Column(
+        TIMESTAMPTZ,
+        nullable=False,
+        server_default=sa.func.now(),
+    )
+    updated_at = Column(
+        TIMESTAMPTZ,
+        nullable=False,
+        server_default=sa.func.now(),
+        onupdate=sa.func.now(),
+    )
+    resolved_at = Column(TIMESTAMPTZ, nullable=True)
+
+    # Relationships
+    reporter = relationship("User", foreign_keys=[reporter_id])
+    resolver = relationship("User", foreign_keys=[resolved_by])
+    moderation_actions = relationship(
+        "ModerationAction",
+        back_populates="report",
+        cascade="all, delete-orphan",
+    )
+    appeals = relationship(
+        "Appeal",
+        back_populates="report",
+        cascade="all, delete-orphan",
+    )

backend/app/models/user.py

@@ -1,13 +1,20 @@
 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, Enum
 from sqlalchemy.orm import relationship
 from sqlalchemy.sql import func
 
 from app.database import Base
 
 
+class UserRole:
+    """Valid user roles."""
+    USER = "user"
+    MODERATOR = "moderator"
+    ADMIN = "admin"
+
+
 class User(Base):
     __tablename__ = "users"
 
@@ -17,12 +24,29 @@ class User(Base):
     hashed_password = Column(String(255), nullable=False)
     date_of_birth = Column(Date, nullable=True)
     is_active = Column(Boolean, default=True)
+    role = Column(
+        Enum(UserRole.USER, UserRole.MODERATOR, UserRole.ADMIN, name="user_role", create_type=False),
+        nullable=False,
+        default=UserRole.USER,
+    )
+    banned_until = Column(DateTime(timezone=True), nullable=True)
+    suspended_until = Column(DateTime(timezone=True), nullable=True)
     created_at = Column(DateTime(timezone=True), server_default=func.now())
     updated_at = Column(DateTime(timezone=True), onupdate=func.now())
 
     sessions = relationship("Session", back_populates="user", cascade="all, delete-orphan")
     worlds = relationship("World", back_populates="owner")
     assets = relationship("Asset", back_populates="owner")
+    moderation_actions_given = relationship(
+        "ModerationAction",
+        foreign_keys="ModerationAction.moderator_id",
+        back_populates="moderator",
+    )
+    moderation_actions_received = relationship(
+        "ModerationAction",
+        foreign_keys="ModerationAction.target_user_id",
+        back_populates="target_user",
+    )
 
     @property
     def is_adult(self) -> bool: