WIP checkpoint: Redis rate-limiting dependency

# Conflicts:
#	.gitignore
#	project.godot

.gitignore

@@ -1,2 +1,10 @@
 # Godot 4 editor cache/import directory
 .godot/
+
+# Godot export artifacts
+export/
+*.tmp
+
+# OS
+.DS_Store
+Thumbs.db

backend/app/config.py

@@ -16,6 +16,7 @@ class Settings(BaseSettings):
 
     # Redis
     REDIS_URL: str = "redis://localhost:6379/0"
+    REDIS_TIMEOUT_SECONDS: float = 2.0
 
     # JWT / Auth
     # NOTE: production must override SECRET_KEY with a secure random value

backend/app/rate_limit.py

@@ -0,0 +1,293 @@
+"""Redis-backed token-bucket rate limiting.
+
+This module provides a reusable FastAPI dependency that rate-limits requests
+per endpoint scope (optionally per-user) using an atomic Lua script on Redis.
+
+If Redis is unavailable the limiter can either allow the request through
+(fail-open) or reject it with a ``503`` (fail-closed), depending on the
+policy configured for that limit. Chat send uses fail-closed by default
+because flooding/abuse is worse than a temporary outage.
+
+Example
+-------
+    from app.rate_limit import rate_limit, named_limit
+
+    chat_send_limit = rate_limit(
+        named_limit("chat_send", capacity=5, refill_rate=0.2, fail_open=False),
+        user_id_dependency=Depends(get_current_user_id),
+    )
+
+    @router.post("/messages")
+    async def send_message(
+        payload: MessageCreate,
+        current_user: CurrentUser,
+        db: DbDep,
+        _: None = Depends(chat_send_limit),
+    ):
+        ...
+"""
+
+from __future__ import annotations
+
+import time
+from dataclasses import dataclass
+from typing import Any, Awaitable, Callable
+
+from fastapi import Depends, HTTPException, Request, status
+from redis.asyncio import Redis
+from redis.exceptions import RedisError
+
+from app.config import settings
+
+# Atomic token-bucket implementation.
+#
+# KEYS[1] is the bucket key. ARGV[1] is the bucket capacity, ARGV[2] is the
+# refill rate in tokens per second, ARGV[3] is the current Unix time in
+# seconds (float), and ARGV[4] is the request cost (tokens to take).
+#
+# The bucket state is stored as a hash with "tokens" and "ts". The script
+# refills the bucket up to capacity, then takes the requested tokens. It
+# returns an array:
+#   [0] allowed (1 or 0)
+#   [1] tokens remaining after the take
+#   [2] retry-after seconds (0 when allowed)
+_TOKEN_BUCKET_LUA = """
+local key = KEYS[1]
+local capacity = tonumber(ARGV[1])
+local refill_rate = tonumber(ARGV[2])
+local now = tonumber(ARGV[3])
+local cost = tonumber(ARGV[4])
+
+local state = redis.call("HMGET", key, "tokens", "ts")
+local tokens = capacity
+local ts = now
+
+if state[1] ~= false then
+    tokens = tonumber(state[1])
+    ts = tonumber(state[2]) or now
+end
+
+local elapsed = math.max(0, now - ts)
+tokens = math.min(capacity, tokens + (elapsed * refill_rate))
+
+local allowed = 0
+local retry_after = 0
+
+if tokens >= cost then
+    tokens = tokens - cost
+    allowed = 1
+else
+    -- Time until enough tokens for a single request have accrued.
+    retry_after = math.ceil((cost - tokens) / refill_rate)
+end
+
+-- Keep the bucket state small and expire-able. Retaining the timestamp as a
+-- float lets partial tokens accumulate smoothly between requests.
+redis.call("HSET", key, "tokens", tostring(tokens), "ts", tostring(now))
+redis.call("PEXPIRE", key, 600000)
+
+return {allowed, tostring(tokens), retry_after}
+"""
+
+
+class RateLimitExceeded(HTTPException):
+    """Raised when a rate-limit bucket has no tokens left."""
+
+    def __init__(self, retry_after: int) -> None:
+        super().__init__(
+            status_code=status.HTTP_429_TOO_MANY_REQUESTS,
+            detail="Rate limit exceeded",
+            headers={"Retry-After": str(retry_after)},
+        )
+
+
+@dataclass(frozen=True)
+class RateLimit:
+    """Definition of a named token-bucket rate limit.
+
+    ``capacity`` is the burst size and ``refill_rate`` is the steady-state
+    token accumulation rate (tokens/second). For example,
+    ``RateLimit(name="chat_send", capacity=10, refill_rate=1.0)`` allows a
+    burst of 10 requests and then one request per second on average.
+    """
+
+    name: str
+    capacity: int
+    refill_rate: float
+    # When Redis is unreachable: ``True`` allows the request (fail-open),
+    # ``False`` rejects it with 503 (fail-closed).
+    fail_open: bool = True
+
+    def __post_init__(self) -> None:
+        if not self.name:
+            raise ValueError("name must be non-empty")
+        if self.capacity <= 0:
+            raise ValueError("capacity must be positive")
+        if self.refill_rate <= 0:
+            raise ValueError("refill_rate must be positive")
+
+
+def default_user_scope(request: Request, user_id: int | None) -> str:
+    """Scope a bucket per authenticated user, or per client IP if anonymous."""
+    if user_id is not None:
+        return f"user:{user_id}"
+    client = request.client
+    return f"ip:{client.host if client else 'unknown'}"
+
+
+@dataclass(frozen=True)
+class RateLimitConfig:
+    """A named rate limit plus how it is applied to a request."""
+
+    limit: RateLimit
+    # Builds the Redis key fragment for the request. The resolved user id is
+    # passed as the second argument (or ``None`` for anonymous limits).
+    scope: Callable[[Request, int | None], str] = default_user_scope
+
+
+@dataclass(frozen=True)
+class RateLimitResult:
+    """Outcome of a rate-limit check (used by tests)."""
+
+    allowed: bool
+    remaining: int
+    retry_after: int
+
+
+_redis_client: Redis | None = None
+
+
+def get_redis() -> Redis:
+    """Return a shared async Redis client for rate limiting.
+
+    The client is created lazily (``Redis.from_url`` does not connect until a
+    command is issued), so this dependency never blocks or fails just because
+    Redis is down.
+    """
+    global _redis_client
+    if _redis_client is None:
+        _redis_client = Redis.from_url(
+            settings.REDIS_URL,
+            encoding="utf-8",
+            decode_responses=True,
+            socket_connect_timeout=settings.REDIS_TIMEOUT_SECONDS,
+            socket_timeout=settings.REDIS_TIMEOUT_SECONDS,
+        )
+    return _redis_client
+
+
+class RateLimiter:
+    """Enforce a token bucket in Redis.
+
+    Buckets are keyed as ``rate:{limit.name}:{scope_key}`` so multiple
+    endpoints can share a named limit while remaining independently bucketed.
+    """
+
+    def __init__(self, config: RateLimitConfig, redis: Redis | None = None) -> None:
+        self._config = config
+        self._redis = redis
+
+    def _redis_client(self) -> Redis:
+        return self._redis or get_redis()
+
+    def _bucket_key(self, request: Request, user_id: int | None) -> str:
+        limit = self._config.limit
+        scope_key = self._config.scope(request, user_id)
+        return f"rate:{limit.name}:{scope_key}"
+
+    async def check(self, request: Request, user_id: int | None = None) -> RateLimitResult:
+        """Atomically refill/take a token and return the outcome.
+
+        Redis failures are mapped to ``allowed=True`` (fail-open) or
+        ``allowed=False`` (fail-closed, represented with ``retry_after=-1``)
+        according to the limit's policy, without raising.
+        """
+        limit = self._config.limit
+        key = self._bucket_key(request, user_id)
+
+        try:
+            result = await self._redis_client().eval(
+                _TOKEN_BUCKET_LUA,
+                1,
+                key,
+                str(limit.capacity),
+                str(limit.refill_rate),
+                str(time.time()),
+                "1",  # each request consumes one token
+            )
+        except RedisError:
+            if limit.fail_open:
+                return RateLimitResult(allowed=True, remaining=0, retry_after=0)
+            # Fail-closed: no reliable retry estimate is available.
+            return RateLimitResult(allowed=False, remaining=0, retry_after=-1)
+
+        # Redis may return ints or strings depending on decode_responses.
+        allowed = bool(int(result[0]))
+        remaining = int(result[1])
+        retry_after = int(result[2])
+        return RateLimitResult(allowed=allowed, remaining=remaining, retry_after=retry_after)
+
+    async def __call__(self, request: Request, user_id: int | None = None) -> None:
+        """Enforce the rate limit, raising 429 or 503 as appropriate."""
+        result = await self.check(request, user_id)
+        if result.allowed:
+            return
+
+        if result.retry_after < 0:
+            # Redis was unavailable and this limit is fail-closed.
+            raise HTTPException(
+                status_code=status.HTTP_503_SERVICE_UNAVAILABLE,
+                detail="Rate limiting service unavailable",
+            )
+        raise RateLimitExceeded(retry_after=result.retry_after)
+
+
+def named_limit(
+    name: str,
+    *,
+    capacity: int,
+    refill_rate: float,
+    fail_open: bool = True,
+) -> RateLimitConfig:
+    """Create a named rate-limit config with the default per-user/IP scope.
+
+    ``capacity`` is the burst size and ``refill_rate`` is tokens/second.
+    """
+    return RateLimitConfig(
+        limit=RateLimit(
+            name=name,
+            capacity=capacity,
+            refill_rate=refill_rate,
+            fail_open=fail_open,
+        )
+    )
+
+
+def rate_limit(
+    config: RateLimitConfig,
+    *,
+    user_id_dependency: Any = None,
+) -> Callable[[Request, Any], Awaitable[None]]:
+    """Build a FastAPI dependency enforcing ``config``.
+
+    ``user_id_dependency`` optionally injects the authenticated user id, e.g.
+    ``Depends(get_current_user_id)``. If omitted the limiter buckets by client
+    IP (the ``default_user_scope`` fallback), which is suitable for anonymous
+    endpoints but should be paired with an auth resolver for per-user limits.
+
+    The returned callable is intended for ``Depends(...)``.
+    """
+
+    async def _anonymous_user_id() -> int | None:
+        return None
+
+    resolver = user_id_dependency if user_id_dependency is not None else Depends(_anonymous_user_id)
+
+    async def dependency(
+        request: Request,
+        user_id: int | None = resolver,
+    ) -> None:
+        limiter = RateLimiter(config)
+        await limiter(request, user_id)
+
+    return dependency

backend/app/routers/assets.py

@@ -1,5 +1,7 @@
 """Asset management router."""
 
+import os
+from pathlib import Path
 from typing import Optional
 
 from fastapi import APIRouter, Depends, HTTPException, UploadFile, File, Query
@@ -51,6 +53,17 @@ class AssetUpdate(BaseModel):
     is_public: Optional[bool] = None
 
 
+# --- Helpers ---
+
+def _sanitize_filename(filename: str) -> str:
+    """Strip path components and unsafe characters from a filename."""
+    # Remove any directory components (path traversal protection).
+    base = os.path.basename(filename.replace("\\", "/"))
+    # Keep only safe characters.
+    safe = "".join(c for c in base if c.isalnum() or c in "._-")
+    return safe or "file"
+
+
 # --- Endpoints ---
 
 @router.post("/", response_model=AssetResponse, status_code=201)
@@ -155,11 +168,11 @@ async def delete_asset(
     await db.commit()
 
 
-@router.post("/{asset_id}/upload")
+@router.post("/{asset_id}/upload", response_model=AssetResponse)
 async def upload_asset_file(
     asset_id: int,
+    current_user: CurrentUser,
     file: UploadFile = File(...),
-    current_user: CurrentUser = None,
     db: AsyncSession = Depends(get_db),
 ):
     """Upload a file for an existing asset."""
@@ -167,11 +180,10 @@ async def upload_asset_file(
     if asset is None or asset.owner_id != current_user.id:
         raise HTTPException(status_code=404, detail="Asset not found")
 
-    # Sanitize filename to prevent path traversal
+    # Sanitize filename to prevent path traversal.
-    safe_filename = file.filename.replace("/", "_").replace("\\", "_") if file.filename else f"asset_{asset_id}"
+    safe_filename = _sanitize_filename(file.filename or f"asset_{asset_id}")
-    file_path = f"uploads/{asset_id}_{safe_filename}"
 
-    # Validate file size against configured maximum
+    # Validate file size against configured maximum.
     max_bytes = settings.MAX_UPLOAD_SIZE_MB * 1024 * 1024
     content = await file.read()
     file_size = len(content)
@@ -181,12 +193,17 @@ async def upload_asset_file(
             detail=f"File size {file_size} exceeds maximum allowed size {max_bytes} bytes",
         )
 
-    # TODO: Implement actual file write logic (S3, local filesystem, etc.)
+    # Write the file to the upload directory.
-    asset.file_path = file_path
+    upload_dir = Path(settings.UPLOAD_DIR)
+    upload_dir.mkdir(parents=True, exist_ok=True)
+    stored_name = f"{asset_id}_{safe_filename}"
+    file_path = upload_dir / stored_name
+    file_path.write_bytes(content)
+
+    asset.file_path = str(file_path)
     asset.mime_type = file.content_type
     asset.file_size = file_size
 
     await db.commit()
     await db.refresh(asset)
-
+    return asset
-    return {"message": "File upload endpoint", "asset_id": asset_id, "file_path": file_path}

backend/app/routers/users.py

@@ -30,7 +30,7 @@ class UserUpdate(BaseModel):
     is_active: bool | None = None
 
 
-# ─── Endpoints ────────────────────────────────────────────────────────────────
+# ─── Endpoints ───────────────────────────────────────────────────────────────
 
 @router.get("/me", response_model=UserResponse)
 async def get_current_user_profile(
@@ -46,15 +46,14 @@ async def get_user(
     current_user: CurrentUser,
     db: Annotated[AsyncSession, Depends(get_db)],
 ):
-    """Get a user by ID.  Owners and admins can see any user; others see
+    """Get a user by ID.  Only the owner can view their own profile."""
-    only their own profile."""
     result = await db.execute(select(User).where(User.id == user_id))
     user = result.scalar_one_or_none()
     if not user:
         raise HTTPException(status_code=404, detail="User not found")
 
-    # Allow viewing own profile or if user is active (admins always allowed)
+    # Only the owner may view their own profile.
-    if user.id != current_user.id and not current_user.is_active:
+    if user.id != current_user.id:
         raise HTTPException(status_code=403, detail="Not authorized to view this user")
 
     return user
@@ -67,13 +66,14 @@ async def update_user(
     current_user: CurrentUser,
     db: Annotated[AsyncSession, Depends(get_db)],
 ):
-    """Update a user.  Only the owner (or an active admin) can update."""
+    """Update a user.  Only the owner can update their own account."""
     result = await db.execute(select(User).where(User.id == user_id))
     user = result.scalar_one_or_none()
     if not user:
         raise HTTPException(status_code=404, detail="User not found")
 
-    if user.id != current_user.id and not current_user.is_active:
+    # Only the owner may update their own account.
+    if user.id != current_user.id:
         raise HTTPException(status_code=403, detail="Not authorized to update this user")
 
     if user_update.email is not None:
@@ -92,13 +92,14 @@ async def delete_user(
     current_user: CurrentUser,
     db: Annotated[AsyncSession, Depends(get_db)],
 ):
-    """Delete a user.  Only the owner (or an active admin) can delete."""
+    """Delete a user.  Only the owner can delete their own account."""
     result = await db.execute(select(User).where(User.id == user_id))
     user = result.scalar_one_or_none()
     if not user:
         raise HTTPException(status_code=404, detail="User not found")
 
-    if user.id != current_user.id and not current_user.is_active:
+    # Only the owner may delete their own account.
+    if user.id != current_user.id:
         raise HTTPException(status_code=403, detail="Not authorized to delete this user")
 
     await db.delete(user)

backend/app/routers/worlds.py

@@ -65,6 +65,12 @@ async def list_worlds(
     # Filter by visibility if specified
     if visibility:
         query = query.where(World.visibility == visibility)
+        if visibility != WorldVisibility.PUBLIC:
+            # Requesting a non-public visibility explicitly must not bypass
+            # ownership — otherwise any authenticated user could list every
+            # PRIVATE/FRIENDS_ONLY world in the system just by passing the
+            # filter, defeating the point of the check below.
+            query = query.where(World.owner_id == current_user.id)
     else:
         # Show PUBLIC worlds + owner's own worlds
         query = query.where(

backend/tests/test_rate_limit.py

@@ -0,0 +1,193 @@
+"""Tests for the Redis-backed token-bucket rate limiter.
+
+These tests use fakeredis (Lua enabled via lupa) so no live Redis server is
+required.
+"""
+
+import asyncio
+import sys
+
+import pytest
+from fastapi import Depends, FastAPI, Request
+from fastapi.testclient import TestClient
+
+sys.path.insert(0, "/workspace")
+
+import fakeredis.aioredis
+from redis.asyncio import Redis
+from redis.exceptions import ConnectionError
+
+from app.rate_limit import (
+    RateLimit,
+    RateLimitConfig,
+    RateLimiter,
+    default_user_scope,
+    named_limit,
+    rate_limit,
+)
+
+
+@pytest.fixture()
+def fake_redis():
+    return fakeredis.aioredis.FakeRedis(decode_responses=True)
+
+
+def make_request(client_ip: str = "127.0.0.1") -> Request:
+    scope = {
+        "type": "http",
+        "method": "GET",
+        "path": "/",
+        "headers": [],
+        "client": (client_ip, 12345),
+    }
+    return Request(scope)
+
+
+@pytest.mark.asyncio
+async def test_token_bucket_allows_burst_then_exhausts(fake_redis):
+    limiter = RateLimiter(
+        RateLimitConfig(
+            limit=RateLimit(name="burst", capacity=3, refill_rate=0.1),
+        ),
+        redis=fake_redis,
+    )
+    request = make_request()
+
+    results = []
+    for _ in range(4):
+        result = await limiter.check(request, user_id=42)
+        results.append(result)
+
+    assert [r.allowed for r in results] == [True, True, True, False]
+    assert results[0].remaining == 2
+    assert results[1].remaining == 1
+    assert results[2].remaining == 0
+    assert results[3].retry_after > 0
+
+
+@pytest.mark.asyncio
+async def test_retry_after_reflects_refill_rate(fake_redis):
+    limiter = RateLimiter(
+        RateLimitConfig(
+            limit=RateLimit(name="slow", capacity=1, refill_rate=0.5),
+        ),
+        redis=fake_redis,
+    )
+    request = make_request()
+
+    assert (await limiter.check(request, user_id=7)).allowed is True
+    denied = await limiter.check(request, user_id=7)
+    assert denied.allowed is False
+    # 1 token / 0.5 tokens per second = 2 seconds.
+    assert denied.retry_after == 2
+
+
+@pytest.mark.asyncio
+async def test_separate_scopes_get_separate_buckets(fake_redis):
+    limiter = RateLimiter(
+        RateLimitConfig(
+            limit=RateLimit(name="scoped", capacity=1, refill_rate=0.1),
+        ),
+        redis=fake_redis,
+    )
+    request = make_request()
+
+    assert (await limiter.check(request, user_id=1)).allowed is True
+    assert (await limiter.check(request, user_id=2)).allowed is True
+    assert (await limiter.check(request, user_id=1)).allowed is False
+
+
+@pytest.mark.asyncio
+async def test_fail_open_returns_allowed_when_redis_unavailable():
+    class BrokenRedis(Redis):
+        async def eval(self, *args, **kwargs):
+            raise ConnectionError("down")
+
+    limiter = RateLimiter(
+        RateLimitConfig(
+            limit=RateLimit(name="open", capacity=1, refill_rate=0.1, fail_open=True),
+        ),
+        redis=BrokenRedis(),
+    )
+    result = await limiter.check(make_request(), user_id=1)
+    assert result.allowed is True
+
+
+@pytest.mark.asyncio
+async def test_fail_closed_returns_denied_with_negative_retry_after():
+    class BrokenRedis(Redis):
+        async def eval(self, *args, **kwargs):
+            raise ConnectionError("down")
+
+    limiter = RateLimiter(
+        RateLimitConfig(
+            limit=RateLimit(name="closed", capacity=1, refill_rate=0.1, fail_open=False),
+        ),
+        redis=BrokenRedis(),
+    )
+    result = await limiter.check(make_request(), user_id=1)
+    assert result.allowed is False
+    assert result.retry_after == -1
+
+
+@pytest.mark.asyncio
+async def test_fail_closed_call_raises_503(fake_redis):
+    class BrokenRedis(Redis):
+        async def eval(self, *args, **kwargs):
+            raise ConnectionError("down")
+
+    limiter = RateLimiter(
+        RateLimitConfig(
+            limit=RateLimit(name="closed", capacity=1, refill_rate=0.1, fail_open=False),
+        ),
+        redis=BrokenRedis(),
+    )
+    with pytest.raises(Exception) as exc_info:
+        await limiter(make_request(), user_id=1)
+    assert exc_info.value.status_code == 503
+
+
+def test_named_limit_builds_expected_config():
+    config = named_limit(
+        "chat_send",
+        capacity=5,
+        refill_rate=0.2,
+        fail_open=False,
+    )
+    assert config.limit.name == "chat_send"
+    assert config.limit.capacity == 5
+    assert config.limit.refill_rate == 0.2
+    assert config.limit.fail_open is False
+    assert config.scope is default_user_scope
+
+
+def test_invalid_limit_definition_rejected():
+    with pytest.raises(ValueError):
+        named_limit("bad", capacity=0, refill_rate=1.0)
+    with pytest.raises(ValueError):
+        named_limit("bad", capacity=1, refill_rate=0)
+
+
+def test_dependency_integration_returns_429_with_retry_after():
+    async def fake_user_id() -> int:
+        return 99
+
+    chat_limit = rate_limit(
+        named_limit("chat_send_test", capacity=2, refill_rate=0.1, fail_open=False),
+        user_id_dependency=Depends(fake_user_id),
+    )
+
+    app = FastAPI()
+
+    @app.get("/probe")
+    async def probe(_: None = Depends(chat_limit)):
+        return {"ok": True}
+
+    client = TestClient(app)
+    assert client.get("/probe").status_code == 200
+    assert client.get("/probe").status_code == 200
+
+    denied = client.get("/probe")
+    assert denied.status_code == 429
+    assert denied.headers["retry-after"]
+    assert denied.json() == {"detail": "Rate limit exceeded"}

docs/architecture/editor.md

@@ -0,0 +1,369 @@
+# Editor Architecture: Godot Editor Plugin vs. In-Game Editor
+
+> **Status:** Proposed
+> **Owner:** Platform team
+> **Related:** World chunk data format & persistence, server authority + client
+> prediction, content moderation & age verification, avatar component system
+> **Godot version:** 4.6.2 stable
+
+## 1. Overview
+
+This document evaluates the two primary ways to build the **world/level
+authoring tool** for **agp-game**:
+
+- **(a) Godot editor plugin** — extend the Godot editor itself with custom
+  panels, dock widgets, and tools that operate on the project's scenes and
+  resources.
+- **(b) In-game editor** — a fully custom editor built as game UI (Godot
+  `Control` nodes) that runs inside the running game, editing the game's own
+  world data.
+
+The goal is to pick the approach that best fits the platform's constraints:
+a **server-authoritative** multiplayer game where the **world is stored as
+versioned chunks** (see `world.md`), content is **moderation-flagged** (see
+`content_moderation.md`), and the client is a **shipped binary** that players
+run (not a dev tool).
+
+This document is a **decision record**: it lays out the trade-offs, gives a
+clear recommendation, and defines the resulting architecture boundaries.
+
+---
+
+## 2. Context & Constraints
+
+Before comparing the two approaches, we must fix the constraints that drive the
+decision. These come from the existing architecture docs.
+
+### 2.1 The World Is Data, Not Scenes
+
+`world.md` defines the world as **chunk data** (JSON for authoring, binary for
+runtime/network), persisted in SQLite on the server. A chunk is the atomic unit
+of load, save, and stream. The **server is the only writer** to the store;
+clients submit **deltas** against a `base_revision` and the server validates and
+applies them.
+
+**Implication:** The editor's output is **chunk payloads**, not `.tscn` scene
+files. Whatever editor we build must serialize to the chunk contract, not to
+Godot scene resources.
+
+### 2.2 Server-Authoritative & Moderation-Aware
+
+- The server validates every edit (schema, bounds, moderation) before
+  persisting (`world.md` §5.4).
+- Content carries **content flags** aggregated from referenced assets/scripts
+  (`content_moderation.md` §3). Mature content is gated behind age verification.
+- The client receives a **content manifest** and never loads content not in it.
+
+**Implication:** An editor that runs on a **player's machine** cannot be the
+authority on what gets published. Editing must go through the server's
+validation pipeline, and the editor must surface moderation flags.
+
+### 2.3 The Client Is a Shipped Binary
+
+The game is a multiplayer product. Players run a **release build**. The Godot
+editor is a **development tool** that players do not have.
+
+**Implication:** If authoring is a first-class *player* feature (user-generated
+content), the editor must ship inside the game binary. If authoring is a
+*developer/platform* feature, it can live in the editor.
+
+### 2.4 Two Distinct Audiences
+
+The evaluation must separate two audiences, because they have opposite needs:
+
+| Audience | Who | Where they run | What they build |
+|----------|-----|----------------|-----------------|
+| **Platform/dev** | The team building the game | Godot editor (dev machines) | Base worlds, rooms, templates, test levels |
+| **Players (UGC)** | End users | The shipped game | Their own rooms/worlds, published to the server |
+
+The two approaches map cleanly onto these audiences, and the right answer is
+likely **both** — but with a clear primary recommendation.
+
+---
+
+## 3. Approach (a): Godot Editor Plugin
+
+### 3.1 What It Is
+
+A Godot editor plugin is a set of scripts (and optionally scenes) that extend
+the editor via the `EditorPlugin` API. It can add:
+
+- **Dock panels** (`add_control_to_dock`) — e.g., a chunk/tile palette panel.
+- **Toolbar buttons** (`add_control_to_container`).
+- **Inspector plugins** (`EditorInspectorPlugin`) — custom property editors.
+- **Import plugins** (`EditorImportPlugin`) — custom asset importers.
+- **Scene/Node plugins** (`EditorNode3DGizmoPlugin`) — custom gizmos.
+- **Menu entries** (`add_tool_menu_item`).
+
+Plugins are enabled per-project via `project.godot` (`[editor_plugins]`).
+
+### 3.2 Pros
+
+- **Full editor power for free:** You get the scene tree, inspector, viewport
+  navigation, undo/redo, gizmos, and asset pipeline — all battle-tested.
+- **Native Godot editing:** Editing `.tscn` scenes, materials, and nodes is
+  exactly what the editor is built for. Great for authoring **base content**
+  (rooms, templates, avatar base bodies).
+- **Fast iteration for devs:** The platform team can build and test levels
+  directly in the tool they already use.
+- **Undo/redo, selection, snapping** come from the editor's `EditorUndoRedoManager`.
+- **No runtime footprint:** Editor-only code is stripped from export builds
+  (`@tool` scripts and editor plugins are not shipped to players).
+
+### 3.3 Cons
+
+- **Not available to players.** Players don't run the Godot editor. Any
+  player-facing UGC authoring cannot use this approach.
+- **Tied to the editor's UX.** You inherit the editor's look and interaction
+  model; deep customization is limited by what the editor API exposes.
+- **Editor API churn.** `EditorPlugin` APIs change between Godot versions;
+  plugins are more brittle across upgrades than game code.
+- **Scene-centric, not data-centric.** The editor is optimized for scenes and
+  resources. Our world is **chunk data** (`world.md`). We'd have to build a
+  translation layer (scene ↔ chunk) and keep it in sync — a real source of
+  drift.
+- **Single-user, local.** The editor edits local files. It does not natively
+  talk to our server-authoritative chunk store or the moderation pipeline.
+- **Headless/CI friction.** Validating plugin behavior in CI requires running
+  the editor headless, which is heavier than testing game code.
+
+### 3.4 Fit for Our Constraints
+
+- **Platform/dev authoring:** Excellent. This is the natural home for building
+  base worlds, rooms, and templates.
+- **Player UGC:** Not applicable. Players cannot run the editor.
+- **Server-authoritative chunk store:** Poor fit natively. The editor edits
+  local scenes; we'd bolt on a chunk export/import and a server sync layer.
+
+---
+
+## 4. Approach (b): In-Game Editor
+
+### 4.1 What It Is
+
+A fully custom editor built as **game UI** — Godot `Control` nodes (panels,
+buttons, toolbars) that run inside the running game. It edits the game's own
+world data model (chunks) and submits edits through the normal server pipeline.
+
+### 4.2 Pros
+
+- **Ships to players.** The editor is part of the game binary, so **player UGC
+  authoring is possible** — the core requirement for a user-generated-content
+  platform.
+- **Data-native.** The editor operates directly on the **chunk model**
+  (`world.md`), so there is no scene↔chunk translation layer and no drift.
+- **Server-authoritative by construction.** Edits go through the same
+  `request_chunk_edit` RPCs as gameplay, so validation, revisioning, and
+  moderation apply uniformly. The editor cannot bypass the server.
+- **Moderation-aware.** Because edits flow through the server, content flags are
+  computed and enforced at the boundary (`content_moderation.md` §4). The editor
+  can surface flags and gate mature content.
+- **One codebase, one UX.** The editor uses the same UI toolkit and art style as
+  the game; no separate editor theme to maintain.
+- **Testable in CI.** The editor is ordinary game code; it can be exercised
+  headlessly and unit-tested like any other system.
+
+### 4.3 Cons
+
+- **We build everything.** No free scene tree, inspector, gizmos, or undo/redo.
+  We must implement selection, snapping, undo/redo, viewport navigation, and
+  property editing ourselves.
+- **Runtime footprint.** Editor UI ships in the binary (though it can be gated
+  behind a feature flag / separate scene that is only instantiated on demand).
+- **More upfront work.** A usable in-game editor is a large feature; it needs
+  its own architecture (tool modes, gizmos, palette, inspector).
+- **Not ideal for deep asset authoring.** Modeling a mesh or authoring a
+  material is better done in the Godot editor / DCC tools. The in-game editor
+  should focus on **world composition** (placing tiles and objects), not asset
+  creation.
+
+### 4.4 Fit for Our Constraints
+
+- **Platform/dev authoring:** Workable but not ideal for deep asset work.
+- **Player UGC:** The **only** viable approach. Players can only author through
+  the shipped game.
+- **Server-authoritative chunk store:** Excellent fit. The editor is a client
+  that submits validated deltas.
+
+---
+
+## 5. Comparison Matrix
+
+| Criterion | (a) Editor plugin | (b) In-game editor |
+|-----------|-------------------|--------------------|
+| Ships to players | ❌ No | ✅ Yes |
+| Player UGC authoring | ❌ Impossible | ✅ Core capability |
+| World data model fit | ⚠️ Scene-centric; needs translation layer | ✅ Chunk-native |
+| Server-authoritative edits | ⚠️ Bolted on | ✅ Native (same RPCs) |
+| Moderation enforcement | ⚠️ Manual | ✅ At the boundary |
+| Free editor features (undo, gizmos, inspector) | ✅ Rich | ❌ Build ourselves |
+| Runtime footprint | ✅ None (stripped from export) | ⚠️ Ships in binary (gated) |
+| Dev iteration speed | ✅ Fast | ⚠️ Slower to build |
+| Deep asset authoring (mesh/material) | ✅ Native | ❌ Out of scope |
+| CI testability | ⚠️ Heavier (headless editor) | ✅ Ordinary game code |
+| Editor API churn risk | ⚠️ Higher | ✅ None (game code) |
+
+---
+
+## 6. Recommendation
+
+**Primary recommendation: build the in-game editor (b) as the platform's
+authoring surface, and use a lightweight Godot editor plugin (a) only as an
+internal dev convenience.**
+
+### 6.1 Rationale
+
+1. **Player UGC is the deciding factor.** The platform's value proposition is
+   user-generated content (rooms, worlds, avatars). Players cannot run the Godot
+   editor, so **only an in-game editor can deliver player authoring**. This is a
+   hard requirement that the editor-plugin approach cannot meet.
+
+2. **The world is data, and the in-game editor is data-native.** `world.md`
+   defines chunks as the atomic unit. An in-game editor edits chunks directly
+   and submits them through the server pipeline. An editor plugin would force a
+   scene↔chunk translation layer that is a constant source of drift and bugs.
+
+3. **Server authority and moderation fall out naturally.** Because in-game
+   edits use the same `request_chunk_edit` RPCs as gameplay, validation,
+   revisioning, optimistic concurrency, and content-flag enforcement
+   (`content_moderation.md`) apply uniformly. The editor cannot bypass the
+   server — which is exactly what a moderation-aware UGC platform needs.
+
+4. **The editor-plugin's strengths are not what we need.** Its free features
+   (scene tree, inspector, gizmos) are for editing Godot scenes and resources.
+   Our authoring is world composition against a chunk contract, not scene
+   editing. The plugin's main win — deep asset authoring — is better served by
+   DCC tools and the Godot editor for the *platform team*, not by a plugin we
+   must maintain.
+
+### 6.2 The Role of the Editor Plugin (Dev Convenience Only)
+
+We still recommend a **small, optional** editor plugin for the **platform team**
+to author **base content** (base rooms, templates, avatar base bodies, test
+levels) directly in the Godot editor. This is a dev-time convenience, not a
+product feature:
+
+- It can export a scene/resource as a **chunk** (reusing the same encoder as the
+  in-game editor) so dev-authored content flows into the same pipeline.
+- It is **not shipped** to players and is **not** the authoring surface for UGC.
+- It should be kept thin to minimize editor-API churn risk.
+
+### 6.3 Scope Boundary
+
+To keep the in-game editor tractable, define its scope clearly:
+
+- **In scope (world composition):** placing tiles, placing static/dynamic
+  objects, setting transforms, editing object properties, saving/loading chunks,
+  submitting edits to the server, showing moderation flags.
+- **Out of scope (asset creation):** modeling meshes, authoring materials,
+  rigging avatars. These are done in DCC tools / the Godot editor and imported
+  as catalog assets (see `avatar.md` §7). The in-game editor **references**
+  catalog assets by id; it does not create them.
+
+---
+
+## 7. Resulting Architecture
+
+### 7.1 Shared Editor Core
+
+Both the in-game editor and the (optional) dev plugin should share a single
+**editor core** that operates on the chunk model. This avoids two divergent
+implementations.
+
+```
+EditorCore (shared, data-native)
+├── ChunkEditorModel      # in-memory chunk being edited (tiles, objects, flags)
+├── ChunkEncoder          # JSON/binary encode/decode (world.md §3)
+├── EditSession           # base_revision tracking, delta generation
+├── EditSubmitter         # request_chunk_edit RPC wrapper + conflict handling
+├── UndoRedoStack         # command pattern over chunk mutations
+├── SelectionManager      # selected tiles/objects
+├── ToolRegistry          # brush, object-place, select, erase, etc.
+└── ModerationView        # surfaces content flags; gates mature content
+```
+
+### 7.2 In-Game Editor (Primary)
+
+```
+InGameEditor (Control-based UI, shipped in binary, gated by feature flag)
+├── EditorViewport        # custom 2D/3D viewport with camera navigation
+├── Toolbar               # tool mode switcher
+├── PalettePanel          # tile/object palette (from catalog)
+├── InspectorPanel        # property editor for selected object
+├── ChunkBrowser          # load/save chunks, list rooms
+└── EditorCore            # shared core (above)
+```
+
+- Instantiated only when the player enters "build mode" (a separate scene /
+  feature flag), so the runtime footprint is negligible during normal play.
+- Submits edits via `request_chunk_edit`; handles `chunk_edit_result` conflicts
+  by re-fetching and re-applying (`world.md` §5.4).
+
+### 7.3 Dev Editor Plugin (Optional, Thin)
+
+```
+DevChunkPlugin (EditorPlugin, dev-only, not shipped)
+├── Dock panel: "Chunk Export"
+├── Reads the current scene / selected nodes
+├── Maps scene content → chunk model (via EditorCore.ChunkEncoder)
+└── Exports a .chunk.json / submits to a dev server
+```
+
+Kept thin to minimize editor-API churn. Its only job is to let the platform team
+author base content in the editor and push it into the same chunk pipeline.
+
+### 7.4 Data Flow
+
+```
+[In-game editor]  --request_chunk_edit(delta, base_revision)-->  [Server]
+        ^                                                          | validate
+        |                                                          | apply
+        +--chunk_edit_result(ok/new_revision | conflict)-----------| persist
+                                                                   v
+                                                              SQLite (world.db)
+
+[Dev plugin]  --export chunk JSON-->  [EditorCore.ChunkEncoder]  -->  [Server]
+```
+
+Both paths converge on the **same server validation pipeline**, so moderation
+and revisioning are uniform regardless of authoring surface.
+
+---
+
+## 8. Risks & Mitigations
+
+| Risk | Mitigation |
+|------|------------|
+| In-game editor is a large build | Scope it to world composition (§6.3); reuse EditorCore; ship behind a feature flag |
+| Custom viewport/gizmos are hard | Start with a 2D tile editor (matches `CHUNK_SIZE_Z=1` default); add 3D later |
+| Undo/redo complexity | Use a command pattern over chunk mutations; test headlessly |
+| Editor-plugin API churn | Keep the plugin thin; treat it as dev-only convenience, not a product surface |
+| Drift between dev plugin and in-game editor | Both use the same `EditorCore`/`ChunkEncoder` |
+| Players bypass moderation | Impossible by construction: edits go through server validation |
+
+---
+
+## 9. Open Questions / Future Work
+
+- **3D editing:** The default world is flat (`CHUNK_SIZE_Z=1`). A 3D in-game
+  editor (volumetric chunks) is future work (`world.md` §8).
+- **Collaborative editing:** Multiple players editing the same chunk concurrently
+  — the optimistic-concurrency model already supports it, but the UX (live
+  cursors, conflict resolution) is unspecified.
+- **Template library:** A curated set of room templates players can start from.
+- **Publish/review flow:** How a player's authored room enters the moderation
+  review queue (`content_moderation.md` §6) and becomes publicly joinable.
+
+---
+
+## 10. Summary
+
+| Concern | Decision |
+|---------|----------|
+| Primary authoring surface | **In-game editor** (ships to players, enables UGC) |
+| Dev authoring convenience | Thin, optional **editor plugin** (not shipped) |
+| World data model | Both operate on the **chunk model** via a shared `EditorCore` |
+| Server authority | Edits go through `request_chunk_edit`; server validates |
+| Moderation | Enforced at the server boundary for both paths |
+| In-game editor scope | World composition only; asset creation is out of scope |
+| Runtime footprint | Editor gated behind a feature flag / separate scene |

docs/architecture/scripting_sandbox.md

@@ -0,0 +1,159 @@
+# GDScript Sandboxing for User-Written Scripts
+
+> **Status:** Proposed
+> **Owner:** Platform team
+> **Related:** Content moderation & age verification (scripts are one of the
+> three moderated content types), avatar component system
+
+## 1. Overview
+
+This document evaluates how to safely run **user-written scripts** as part of
+UGC (user-generated content) in **agp-game**, and recommends an approach.
+
+**Bottom line: Godot 4 has no built-in security sandbox for GDScript, and
+none of the three options named in the original task hold up under testing.**
+A script running anywhere inside the Godot process — however it's loaded,
+parented, or wrapped — runs with full engine privileges: arbitrary process
+execution, full filesystem read/write, and raw network access. Sandboxing
+has to happen *outside* the scripting language, not through an in-engine
+restriction mechanism, because no such mechanism exists.
+
+This was verified directly against Godot 4.6.2 (`godot --headless`, evidence
+in `sandbox_probe/` on this branch) rather than assumed from documentation,
+some of which (see §2.1) describes APIs that don't actually exist in this
+version.
+
+## 2. Options Evaluated
+
+### 2.1 Godot's built-in "ScriptServer" restrictions — does not exist
+
+There is no `ScriptServer` class in Godot 4.6.2:
+
+```
+ClassDB.class_exists("ScriptServer")  →  false
+```
+
+There's also no project setting to disable engine subsystems for scripts —
+none of `application/run/disable_os`, `disable_file_access`, or
+`disable_network` exist as settings, and `ProjectSettings.get_property_list()`
+returns nothing matching "sandbox", "restrict", or "security". Any plan that
+assumes a flag like this exists needs to be dropped; it was likely conflated
+with sandboxing features from a different engine/scripting ecosystem, or
+with **export template stripping** (which controls what ships in a build,
+not what a script can call at runtime).
+
+Directly probed capabilities of an ordinary GDScript running as a normal
+node script, no special setup:
+
+| Capability | Available to any script? |
+|---|---|
+| `OS.execute(...)` — run arbitrary processes | ✅ Yes |
+| `FileAccess.open(...)` — read/write any path the OS user can reach | ✅ Yes (read `/etc/hostname`, write `/tmp/...` both succeeded) |
+| `TCPServer` / `HTTPClient` / `HTTPRequest` / `PacketPeerUDP` / `WebSocketPeer` | ✅ All instantiate and work |
+| `ClassDB.instantiate(...)` — construct any engine class by name | ✅ Yes |
+| Loading and running a second script from source text at runtime (`GDScript.new()` + `.reload()`) | ✅ Yes |
+
+**Verdict: rejected.** There is nothing to configure here — the restriction
+surface this option assumed doesn't exist in the engine.
+
+### 2.2 Isolated SubViewport with a limited API — doesn't isolate scripts
+
+`SubViewport` is a **rendering and input isolation** primitive (it gives a
+scene subtree its own render target and can gate input propagation) — it is
+not a security or scripting boundary. A script attached to any node inside a
+`SubViewport` still runs in the same process, on the same GDScript VM, with
+the exact same access to `OS`, `FileAccess`, networking classes, and
+`ClassDB` as a script anywhere else in the tree. Nothing about being
+"inside" a SubViewport changes what API calls are reachable from a script.
+
+**Verdict: rejected.** This solves a rendering/UI-composition problem, not
+the security problem the task is asking about. Worth keeping in mind for
+other purposes (e.g. isolated preview rendering of user avatars), but it
+provides zero script sandboxing.
+
+### 2.3 Custom GDScript interpreter with an allowlist — right idea, wrong layer for "custom interpreter"
+
+Two ways to read this option, tested separately:
+
+**(a) Write/embed a separate GDScript parser+interpreter.** Not
+practical — this means re-implementing (and then indefinitely maintaining,
+in lockstep with every Godot release) a full language interpreter outside
+the engine. Far more engineering than the problem justifies.
+
+**(b) Use Godot's built-in `Expression` class as a restricted subset.**
+`Expression` *looks* like a natural allowlist mechanism — it only evaluates
+a single expression, no control flow, no arbitrary statements. But it isn't
+safe by default: it can still reach through to unsafe engine methods if you
+aren't careful about what object you hand it as a base instance:
+
+```gdscript
+var expr = Expression.new()
+expr.parse("get_environment('HOME')", ["OS"])
+expr.execute([], OS)   # → "/home/daddy"  (successfully called OS.get_environment)
+```
+
+So `Expression` is a viable building block only if the host **never passes
+a base instance (or arguments) that exposes anything sensitive** — i.e. the
+allowlisting work still has to happen at the call site, `Expression` itself
+enforces none of it.
+
+**Static text pattern-matching (blocklisting dangerous substrings like
+`"OS.execute"` before parsing) was also probed and is not a real
+defense** — it's trivially defeated by string concatenation, `call()`,
+`Callable`, or any other indirection, and produces false confidence.
+
+**Verdict: partially viable, but only as a foundation, not a solution on
+its own.** A hand-built, narrow, data-driven DSL (not full GDScript, not
+raw `Expression`) with an explicit allowlist of safe operations and *no
+ability to reference engine singletons or arbitrary objects* is the only
+version of "custom interpreter" that's actually safe. This is real
+engineering effort, not a config flag.
+
+## 3. Recommendation
+
+**Don't run untrusted GDScript in-process at all.** Given none of the three
+in-engine options provide a real boundary, the two approaches actually worth
+building are, in order of recommended priority:
+
+1. **Primary: a narrow, non-Turing-complete content DSL**, not general
+   scripting. Most UGC scripting needs in a game like this (custom
+   interactions, simple triggers, item behaviors) don't need a general
+   programming language — they need a small set of declarative
+   verbs/conditions (e.g. `on_interact: give_item("torch")`,
+   `on_enter: play_sound("chime")`). Expressed as data (JSON/Resource, not
+   code) and interpreted by trusted, hand-written GDScript on the engine
+   side. This has *zero* attack surface by construction — there's no
+   interpreter to escape because there's no general execution, just a
+   fixed, reviewed set of verbs. This is almost certainly sufficient for
+   the actual UGC use cases in this game and should be scoped against real
+   feature requirements before assuming more is needed.
+
+2. **If genuinely general scripting becomes a hard requirement**, isolate it
+   at the OS level, not the engine level: run untrusted scripts in a
+   **separate process** (a stripped-down Godot instance or a dedicated
+   interpreter) under OS sandboxing (a restricted user account, a
+   container, or `firejail`/`bwrap`/seccomp), communicating with the main
+   game over a narrow IPC/RPC boundary that only exposes intentionally-safe
+   operations. This is the only approach that provides a real security
+   boundary for arbitrary code, because it doesn't depend on the scripting
+   language cooperating — the OS enforces it. Substantially more
+   infrastructure than option 1; only worth it if option 1's DSL genuinely
+   can't express what's needed.
+
+**Do not** attempt in-process GDScript sandboxing via SubViewport,
+ScriptServer, or ad hoc blocklisting — all three were directly tested and
+none provide a real boundary (§2).
+
+## 4. Open Questions
+
+- What do actual planned UGC scripts need to *do*? (Trigger conditions,
+  simple item/state effects, dialogue branching?) This determines whether
+  the DSL in §3.1 is sufficient or whether §3.2's process isolation is
+  needed. Needs a concrete feature list before implementation starts.
+- If §3.2 is needed later, does it run per-user-session or shared/pooled?
+  Affects resource cost and isolation guarantees.
+- Interaction with the content moderation pipeline (`content_moderation.md`):
+  scripts as a moderated content type still need a moderation flag path
+  regardless of which execution model is chosen — a DSL makes static
+  analysis of *what a script can possibly do* far easier than it would be
+  for general code, which is an additional point in its favor.

docs/planning/social.md

@@ -0,0 +1,170 @@
+# Social — Friends, Chat & Groups — Plan
+
+> **Status:** Planned
+> **Owner:** Platform team
+> **Feature ID:** `social`
+> **Godot version:** 4.6.2 stable
+> **Backend:** FastAPI + SQLAlchemy (async) + PostgreSQL + Redis
+
+## 1. Overview
+
+This document breaks the **Social** feature into user stories and right-sized
+implementation tasks. The feature delivers:
+
+- **Friends & following** — a friend request/accept model plus a one-way follow
+  relationship, with block lists.
+- **Presence & status** — online/offline, custom status message, last-seen.
+- **Chat** — direct messages (DM) and in-experience (world/room) chat with
+  **first-class safety**: server-side text filtering, report-message, and rate
+  limiting.
+- **Groups** — named groups with roles (owner/admin/member) and a simple group
+  page.
+- **Public profiles** — avatar, bio, favorite experiences, and a friends list
+  that respects privacy settings.
+
+## 2. Why chat safety is the differentiator
+
+The platform is explicitly meant to pull adults away from a youth-oriented
+competitor. Chat is the highest-risk surface: it is real-time, user-generated,
+and where abuse happens fastest. Safety is therefore treated as a **blocking
+requirement**, not an add-on:
+
+- Every message passes a **server-side text filter** before it is stored or
+  delivered. The client filter is cosmetic only; the server is authoritative.
+- Every message can be **reported**; reports flow into a moderation queue with
+  actor + reason + audit trail (mirroring `content_moderation.md`).
+- Sending is **rate limited** per user (Redis token bucket) to stop flooding and
+  harassment-by-volume.
+- Report and block are always reachable from a message context in the UI.
+
+## 3. Existing constraints (do not re-build)
+
+- **Auth:** JWT bearer tokens; `get_current_user` / `CurrentUser` dependency in
+  `app/dependencies.py`. All social endpoints reuse this.
+- **DB:** async SQLAlchemy + Alembic; migration `0001_initial` is the head.
+- **Redis:** configured (`REDIS_URL`) but unused so far; adopted here for
+  presence and rate limiting.
+- **Models:** `User`, `World` (owner_id), `Asset` (owner_id, is_public). Avatars
+  and favorite-experience references point at existing rows.
+- **Client:** Godot 4.6.2, minimal `main_menu.gd`; no social UI yet.
+
+## 4. Key design decisions
+
+| Concern | Decision |
+|---|---|
+| Message transport | REST for send/history; **WebSocket** gateway for real-time delivery + presence (matches `networking.md`'s "WebSocket as secondary transport" for chat) |
+| Presence store | Redis (TTL heartbeat) + persisted `last_seen_at` on the user record |
+| Text filtering | Pluggable `TextFilter` interface with a deterministic default (profanity list + normalization) so it runs without external services; third-party hook later |
+| Rate limiting | Redis token-bucket dependency, reusable across all social endpoints |
+| Reports | `message_reports` table + moderation endpoints (list/review/resolve) with audit fields |
+| Friends vs. follow | Friends = mutual (request→accept). Follow = one-way (no approval). Block = hard deny that also hides content and prevents DMs |
+| Privacy | Per-user settings JSON (`profile_visibility`, `friends_list_visibility`, `favorites_visibility`) enforced server-side on every read |
+| Groups | `groups` + `group_members` (role: owner/admin/member) + group page aggregate endpoint |
+| Real-time | One WebSocket endpoint multiplexing presence, DM, and world-chat messages via Redis pub/sub |
+
+## 5. User stories
+
+### US-1 Friends & following
+As a player, I can send a friend request, accept/decline incoming requests,
+unfriend, follow/unfollow other players, and block users so they can't interact
+with me.
+
+**Acceptance criteria**
+- Friend requests are one-directional until accepted; accepted friendships are mutual.
+- Follow is one-way and requires no approval.
+- Block prevents DMs, hides the blocked user's profile/friends interactions, and
+  removes any existing friendship/follow between the two.
+- Duplicate/self requests are rejected idempotently.
+
+### US-2 Presence & status
+As a player, I can see whether my friends are online, their custom status, and
+when they were last seen.
+
+**Acceptance criteria**
+- Online/offline is derived from a server-side heartbeat (Redis TTL), not client claims.
+- `last_seen_at` persists and is visible (subject to privacy settings).
+- Custom status text is optional and length-limited.
+
+### US-3 Public profiles
+As a player, I can view a public profile page showing avatar, bio, favorite
+experiences, and a friends list that respects the owner's privacy settings.
+
+**Acceptance criteria**
+- Avatar and bio are editable by the owner only.
+- Favorite experiences reference existing `World` rows.
+- A viewer sees only the sections the owner's privacy settings allow; blocked
+  users see a restricted view.
+
+### US-4 Chat (DM + in-experience) with safety
+As a player, I can send direct messages and chat inside a world/room. Messages
+are filtered, rate limited, and reportable.
+
+**Acceptance criteria**
+- Server filters message text before storing/delivering; filtered content is either
+  rejected (blocking) or redacted (configurable per filter policy).
+- Send rate is limited per user (token bucket); excess sends get `429`.
+- Every message has a stable id, author, timestamp, and conversation/world scope.
+- Any message can be reported with a reason; reports are stored and reviewable.
+- Real-time delivery over WebSocket with REST fallback for history.
+
+### US-5 Groups
+As a player, I can create a group, join/leave groups, and (as owner/admin)
+manage roles and view a simple group page.
+
+**Acceptance criteria**
+- Each group has exactly one owner and any number of admins/members.
+- Role transitions are authorized (only owner can transfer ownership or promote/demote admins).
+- Group page lists name, description, member list with roles, and member count.
+
+### US-6 Godot client
+As a player, I can access friends, presence, chat, profiles, and groups from the
+game UI.
+
+**Acceptance criteria**
+- An API client handles JWT auth, HTTP, and WebSocket for all social calls.
+- Dedicated screens/panels: friends+presence, DM & world chat (with report),
+  profile page, group page.
+- Client-side filtering is cosmetic; server responses remain authoritative.
+
+## 6. Task breakdown
+
+Right-sized to 1–3 files / one coherent piece of functionality each. Task IDs
+are sequential for dependency chaining.
+
+| # | Task | Story | Depends on |
+|---|------|-------|-----------|
+| 1 | Friends/follow/block models + Alembic migration | US-1 | — |
+| 2 | Friends & follow API router | US-1 | 1 |
+| 3 | Presence & status model + endpoints (Redis heartbeat) | US-2 | — |
+| 4 | Profile model + migration + own-profile endpoints | US-3 | 1 |
+| 5 | Public profile view + favorites + privacy enforcement | US-3 | 2, 4 |
+| 6 | Chat data models + migration (conversations, messages, reports) | US-4 | — |
+| 7 | Text filtering service + profanity config | US-4 | — |
+| 8 | Redis rate-limiting dependency | US-4 | — |
+| 9 | DM chat send/list endpoints (filter + rate limit) | US-4 | 6, 7, 8 |
+| 10 | Report-message endpoint + moderation queue | US-4 | 6, 9 |
+| 11 | In-experience (world/room) chat endpoints | US-4 | 9 |
+| 12 | Real-time WebSocket gateway (presence + DM + world chat) | US-4 | 3, 9, 11 |
+| 13 | Group + membership models + migration | US-5 | — |
+| 14 | Groups API (CRUD, join/leave, roles, group page) | US-5 | 13 |
+| 15 | Godot API client (auth + HTTP + WebSocket) | US-6 | 2 |
+| 16 | Godot friends & presence UI | US-6 | 3, 15 |
+| 17 | Godot chat UI (DM + world chat + report) | US-6 | 12, 15 |
+| 18 | Godot profile page UI | US-6 | 5, 15 |
+| 19 | Godot groups UI + group page | US-6 | 14, 15 |
+
+## 7. Phasing
+
+- **Phase 1 (data + core APIs):** tasks 1–5 (friends, presence, profiles).
+- **Phase 2 (chat safety — the differentiator):** tasks 6–12 (chat + safety +
+  realtime). This is the critical path and highest priority.
+- **Phase 3 (groups):** tasks 13–14.
+- **Phase 4 (client):** tasks 15–19, each landing after its backend dependency.
+
+## 8. Out of scope for this feature
+
+- Age verification / maturity gating (covered by `content_moderation.md`).
+- Voice chat, media/image messages, message editing/deletion history.
+- Third-party profanity/toxicity vendors (the `TextFilter` interface leaves a
+  hook, but the default is deterministic and dependency-free).
+- Mobile push notifications.

sandbox_probe/.godot/.gdignore

@@ -0,0 +1 @@
+

sandbox_probe/probe6.gd

@@ -0,0 +1,174 @@
+extends Node
+
+func _ready():
+	print("=== SANDBOX PROBE 6: Corrected Evidence Gathering (Godot 4.6.2) ===")
+	probe_script_loading()
+	probe_os_apis()
+	probe_file_access()
+	probe_network()
+	probe_classdb()
+	probe_expression_engine()
+	probe_engine_singletons()
+	probe_worker_threads()
+	probe_project_settings()
+	probe_allowlist()
+	print("=== SANDBOX PROBE 6 END ===")
+	get_tree().quit()
+
+func probe_script_loading():
+	print("--- Script loading ---")
+	var gd = GDScript.new()
+	gd.source_code = "extends RefCounted\nfunc hello():\n\treturn 42\n"
+	var err = gd.reload()
+	print("GDScript.reload() from source_code err=", err)
+	if err == OK:
+		var inst = gd.new()
+		print("  instantiated, hello()=", inst.call("hello"))
+	var res = load("res://test_script.gd")
+	print("load('res://test_script.gd') = ", res)
+	if res:
+		print("  get_source_code() available: ", res.has_method("get_source_code"))
+	print("  GDScript instance has 'get_ast': ", gd.has_method("get_ast"))
+	print("  GDScript instance has 'get_parser': ", gd.has_method("get_parser"))
+	print("  GDScript instance has 'get_script_method_list': ", gd.has_method("get_script_method_list"))
+	print("  GDScript instance has 'get_script_property_list': ", gd.has_method("get_script_property_list"))
+
+func probe_os_apis():
+	print("--- OS APIs ---")
+	var out = []
+	var exit_code = OS.execute("echo", ["hello"], out)
+	print("OS.execute('echo') exit=", exit_code, " out=", out)
+	print("OS.get_environment('HOME') = ", OS.get_environment("HOME"))
+	print("OS has 'create_process': ", OS.has_method("create_process"))
+	print("OS.get_cmdline_args() = ", OS.get_cmdline_args())
+	print("OS.get_user_data_dir() = ", OS.get_user_data_dir())
+	print("OS.get_executable_path() = ", OS.get_executable_path())
+
+func probe_file_access():
+	print("--- File access ---")
+	var f = FileAccess.open("/etc/hostname", FileAccess.READ)
+	print("FileAccess.open('/etc/hostname') = ", f)
+	if f:
+		print("  content: ", f.get_as_text())
+		f.close()
+	var w = FileAccess.open("/tmp/godot_probe_write.txt", FileAccess.WRITE)
+	print("FileAccess.open('/tmp/...', WRITE) = ", w)
+	if w:
+		w.store_string("probe")
+		w.close()
+		print("  wrote to /tmp OK")
+	var dir = DirAccess.open("/")
+	print("DirAccess.open('/') = ", dir)
+	if dir:
+		var names = dir.get_files()
+		print("  root files count: ", names.size())
+	var res_dir = DirAccess.open("res://")
+	print("DirAccess.open('res://') = ", res_dir)
+	var user_dir = DirAccess.open("user://")
+	print("DirAccess.open('user://') = ", user_dir)
+
+func probe_network():
+	print("--- Network ---")
+	var tcp = TCPServer.new()
+	var bind_err = tcp.listen(0)
+	print("TCPServer.listen(0) err=", bind_err)
+	var http = HTTPClient.new()
+	print("HTTPClient instantiated: ", http != null)
+	var http_req = HTTPRequest.new()
+	print("HTTPRequest instantiated: ", http_req != null)
+	var udp = PacketPeerUDP.new()
+	print("PacketPeerUDP instantiated: ", udp != null)
+	var ws = WebSocketPeer.new()
+	print("WebSocketPeer instantiated: ", ws != null)
+
+func probe_classdb():
+	print("--- ClassDB ---")
+	print("ClassDB.class_exists('OS'): ", ClassDB.class_exists("OS"))
+	print("ClassDB.class_exists('FileAccess'): ", ClassDB.class_exists("FileAccess"))
+	print("ClassDB.class_exists('TCPServer'): ", ClassDB.class_exists("TCPServer"))
+	print("ClassDB.class_exists('HTTPClient'): ", ClassDB.class_exists("HTTPClient"))
+	var class_list = ClassDB.get_class_list()
+	print("ClassDB.get_class_list() count: ", class_list.size())
+	var os_methods = ClassDB.class_get_method_list("OS")
+	print("OS method count: ", os_methods.size())
+	var inst = ClassDB.instantiate("Node")
+	print("ClassDB.instantiate('Node') = ", inst)
+	print("ClassDB has 'class_get_singleton': ", ClassDB.has_method("class_get_singleton"))
+
+func probe_expression_engine():
+	print("--- Expression engine ---")
+	var expr = Expression.new()
+	var err = expr.parse("1 + 2")
+	print("Expression.parse('1 + 2') err=", err)
+	if err == OK:
+		var result = expr.execute()
+		print("  Expression.execute() = ", result)
+	var expr2 = Expression.new()
+	err = expr2.parse("OS.get_environment('HOME')")
+	print("Expression.parse('OS.get_environment') err=", err)
+	if err == OK:
+		var result2 = expr2.execute()
+		print("  Expression.execute() = ", result2)
+	var expr3 = Expression.new()
+	err = expr3.parse("get_environment('HOME')", ["OS"])
+	print("Expression.parse with base_instance err=", err)
+	if err == OK:
+		var result3 = expr3.execute([], OS)
+		print("  Expression.execute with OS base = ", result3)
+	var expr4 = Expression.new()
+	err = expr4.parse("FileAccess.open('/etc/hostname', 1)")
+	print("Expression.parse('FileAccess.open') err=", err)
+	if err == OK:
+		var result4 = expr4.execute()
+		print("  Expression.execute() = ", result4)
+	var expr5 = Expression.new()
+	err = expr5.parse("get_tree().quit()")
+	print("Expression.parse('get_tree().quit()') err=", err)
+	if err == OK:
+		var result5 = expr5.execute()
+		print("  Expression.execute() = ", result5)
+
+func probe_engine_singletons():
+	print("--- Engine singletons ---")
+	print("Engine has 'remove_singleton': ", Engine.has_method("remove_singleton"))
+	print("Engine has 'add_singleton': ", Engine.has_method("add_singleton"))
+	print("Engine.get_main_loop() = ", Engine.get_main_loop())
+
+func probe_worker_threads():
+	print("--- Worker threads ---")
+	var thread = Thread.new()
+	print("  Thread.new() = ", thread)
+	print("  WorkerThreadPool has 'add_task': ", WorkerThreadPool.has_method("add_task"))
+
+func probe_project_settings():
+	print("--- Project settings ---")
+	var settings = ProjectSettings.get_property_list()
+	var relevant = []
+	for s in settings:
+		var name = String(s.name)
+		if "sandbox" in name.to_lower() or "restrict" in name.to_lower() or "security" in name.to_lower():
+			relevant.append(name)
+	print("  Sandbox/security project settings: ", relevant)
+	print("  ProjectSettings has 'application/run/disable_os': ", ProjectSettings.has_setting("application/run/disable_os"))
+	print("  ProjectSettings has 'application/run/disable_file_access': ", ProjectSettings.has_setting("application/run/disable_file_access"))
+	print("  ProjectSettings has 'application/run/disable_network': ", ProjectSettings.has_setting("application/run/disable_network"))
+	print("  ProjectSettings has 'set_setting': ", ProjectSettings.has_method("set_setting"))
+	print("  ProjectSettings has 'save': ", ProjectSettings.has_method("save"))
+
+func probe_allowlist():
+	print("--- Allowlist / static analysis ---")
+	var dangerous_patterns = [
+		"OS.execute", "OS.create_process", "OS.get_environment",
+		"FileAccess.open", "DirAccess.open", "TCPServer", "HTTPClient",
+		"load(", "preload(", "ClassDB", "Engine.get_main_loop",
+		"get_tree().quit", "ProjectSettings"
+	]
+	var test_script = """extends Node
+func _ready():
+	var f = FileAccess.open("/etc/passwd", FileAccess.READ)
+	OS.execute("rm", ["-rf", "/"])
+"""
+	print("  Test script contains dangerous patterns:")
+	for p in dangerous_patterns:
+		if p in test_script:
+			print("    DETECTED: ", p)

sandbox_probe/probe6.tscn

@@ -0,0 +1,6 @@
+[gd_scene load_steps=2 format=3]
+
+[ext_resource type="Script" path="res://probe6.gd" id="1"]
+
+[node name="Probe6" type="Node"]
+script = ExtResource("1")

sandbox_probe/project.godot

@@ -0,0 +1,8 @@
+; Engine configuration file.
+config_version=5
+
+[application]
+
+config/name="sandbox_probe"
+run/main_scene="res://probe6.tscn"
+config/features=PackedStringArray("4.6")

sandbox_probe/test_script.gd

@@ -0,0 +1,4 @@
+extends RefCounted
+
+func hello():
+	return "from test_script.gd"

scenes/main.tscn

@@ -0,0 +1,6 @@
+[gd_scene load_steps=2 format=3 uid="uid://main_scene"]
+
+[ext_resource type="Script" path="res://scripts/chunk_stream_manager.gd" id="1_chunk_stream"]
+
+[node name="Main" type="Node3D"]
+script = ExtResource("1_chunk_stream")

scripts/chunk.gd

@@ -0,0 +1,105 @@
+class_name Chunk
+extends Node3D
+## A single world chunk. Holds the chunk coordinate, bounds, and the
+## visual/gameplay content for that region of the world.
+##
+## Chunks are the atomic unit of world geometry, gameplay objects, and
+## persistence (see docs/architecture/world.md). The server loads and saves
+## whole chunks; clients stream the chunks around them.
+
+## Default chunk dimensions in world units (tiles). Matches the constants in
+## docs/architecture/world.md section 2.2.
+const CHUNK_SIZE_X: int = 32
+const CHUNK_SIZE_Y: int = 32
+const CHUNK_SIZE_Z: int = 1
+
+## World-space origin of chunk coordinate (0,0).
+const CHUNK_ORIGIN := Vector3(0.0, 0.0, 0.0)
+
+## Chunk coordinate (cx, cy, cz) in chunk space.
+var coord := Vector3i.ZERO
+
+## The canonical chunk key: "{world_id}:{room_id}:{cx}:{cy}:{cz}".
+var key: String = ""
+
+## World and room identifiers this chunk belongs to.
+var world_id: String = ""
+var room_id: String = ""
+
+## Format version of the chunk payload (currently 1).
+var format_version: int = 1
+
+## Revision counter, incremented on every write. Used for optimistic
+## concurrency and change detection.
+var revision: int = 0
+
+## Whether this chunk has been modified in memory but not yet flushed.
+var dirty: bool = false
+
+## Container for static objects (props, geometry) in this chunk.
+var objects: Array[Node3D] = []
+
+## Container for dynamic object templates (spawnable entities).
+var dynamic_templates: Array[Node3D] = []
+
+## The world-space bounding box of this chunk.
+var bounds: AABB
+
+
+func _init(p_coord: Vector3i = Vector3i.ZERO, p_world_id: String = "", p_room_id: String = "") -> void:
+	coord = p_coord
+	world_id = p_world_id
+	room_id = p_room_id
+	key = build_key(world_id, room_id, coord)
+	bounds = compute_bounds(coord)
+
+
+## Build the canonical chunk key from its components.
+static func build_key(p_world_id: String, p_room_id: String, p_coord: Vector3i) -> String:
+	return "%s:%s:%d:%d:%d" % [p_world_id, p_room_id, p_coord.x, p_coord.y, p_coord.z]
+
+
+## Compute the world-space bounding box for a chunk coordinate.
+static func compute_bounds(p_coord: Vector3i) -> AABB:
+	var min_pos := Vector3(
+		CHUNK_ORIGIN.x + p_coord.x * CHUNK_SIZE_X,
+		CHUNK_ORIGIN.y + p_coord.y * CHUNK_SIZE_Y,
+		CHUNK_ORIGIN.z + p_coord.z * CHUNK_SIZE_Z
+	)
+	return AABB(min_pos, Vector3(CHUNK_SIZE_X, CHUNK_SIZE_Y, CHUNK_SIZE_Z))
+
+
+## Compute the chunk coordinate that contains a world-space position.
+static func coord_for_position(p_pos: Vector3) -> Vector3i:
+	return Vector3i(
+		int(floor((p_pos.x - CHUNK_ORIGIN.x) / CHUNK_SIZE_X)),
+		int(floor((p_pos.y - CHUNK_ORIGIN.y) / CHUNK_SIZE_Y)),
+		int(floor((p_pos.z - CHUNK_ORIGIN.z) / CHUNK_SIZE_Z))
+	)
+
+
+## Add a static object to this chunk.
+func add_object(p_object: Node3D) -> void:
+	objects.append(p_object)
+	add_child(p_object)
+
+
+## Add a dynamic object template to this chunk.
+func add_dynamic_template(p_template: Node3D) -> void:
+	dynamic_templates.append(p_template)
+	add_child(p_template)
+
+
+## Remove all objects from this chunk.
+func clear_objects() -> void:
+	for obj in objects:
+		if is_instance_valid(obj):
+			obj.queue_free()
+	objects.clear()
+	dynamic_templates.clear()
+
+
+## Mark this chunk as dirty (modified but not yet persisted).
+func mark_dirty() -> void:
+	dirty = true
+	revision += 1

scripts/chunk.gd.uid

@@ -0,0 +1 @@
+uid://dc6j7kqjitc6g

scripts/chunk_data_decoder.gd

@@ -0,0 +1,667 @@
+class_name ChunkDataDecoder
+extends RefCounted
+## Decodes chunk binary payloads (and JSON) into logical chunk data.
+##
+## Implements the binary format spec from docs/architecture/world.md §3.6.
+## Both the Godot client and Python backend use this class to ensure
+## identical encoding/decoding behavior.
+##
+## ## Binary Format Overview
+##
+## ```
+## Header (48 bytes):
+##   [0:4]   magic "AGPC"
+##   [4:6]   version (uint16 LE)
+##   [6:8]   header_len (uint16 LE)
+##   [8:12]  flags (uint32 LE)
+##   [12:16] payload_len (uint32 LE)
+##   [16:48] checksum (SHA-256 hex, 32 bytes)
+##
+## Payload Body (sections):
+##   [section_id:1][section_len:4][data:section_len]
+## ```
+
+
+## Content flags parsed from a chunk.
+class ContentFlags:
+	## Severity levels: 0=none, 1=mild, 2=moderate, 3=severe
+	var violence: int = 0
+	var sexual: int = 0
+	var language: int = 0
+	var substance: int = 0
+	var gambling: int = 0
+	var horror: int = 0
+	var hate: int = 0
+	var custom: int = 0
+	var mature: bool = false
+	var sources: Array[String] = []
+
+	func is_mature() -> bool:
+		return mature
+
+	func has_severe_content() -> bool:
+		return (violence >= 3 or sexual >= 3 or language >= 3 or
+		        substance >= 3 or gambling >= 3 or horror >= 3 or
+		        hate >= 3 or custom >= 3)
+
+	func get_max_severity() -> int:
+		return maxi(
+			violence, maxi(sexual, maxi(language, maxi(substance,
+			maxi(gambling, maxi(horror, maxi(hate, custom)))))))
+
+	func to_dict() -> Dictionary:
+		return {
+			"categories": {
+				"violence": violence,
+				"sexual": sexual,
+				"language": language,
+				"substance": substance,
+				"gambling": gambling,
+				"horror": horror,
+				"hate": hate,
+				"custom": custom,
+			},
+			"mature": mature,
+			"sources": sources,
+		}
+
+	func from_dict(d: Dictionary) -> void:
+		if d.has("categories"):
+			violence = d["categories"].get("violence", 0)
+			sexual = d["categories"].get("sexual", 0)
+			language = d["categories"].get("language", 0)
+			substance = d["categories"].get("substance", 0)
+			gambling = d["categories"].get("gambling", 0)
+			horror = d["categories"].get("horror", 0)
+			hate = d["categories"].get("hate", 0)
+			custom = d["categories"].get("custom", 0)
+		mature = d.get("mature", false)
+		sources = d.get("sources", [])
+
+
+## A tile layer definition (palette + dense tile indices).
+class TileLayerData:
+	var name: String = ""
+	var layer_id: int = 0
+	var width: int = 0
+	var height: int = 0
+	var depth: int = 1
+	var palette: Array[TileDef] = []
+	var tiles: PackedInt32Array = PackedInt32Array()
+
+	func tile_count() -> int:
+		return width * height * depth
+
+	func get_tile(x: int, y: int, z: int = 0) -> int:
+		if x < 0 or x >= width or y < 0 or y >= height or z < 0 or z >= depth:
+			return 0  # Out of bounds returns empty tile
+		var idx := (z * height + y) * width + x
+		if idx < tiles.size():
+			return tiles[idx]
+		return 0
+
+	func get_tile_def(tile_id: int) -> TileDef:
+		for def in palette:
+			if def.id == tile_id:
+				return def
+		return null
+
+
+## A world object parsed from chunk data.
+class WorldObjectData:
+	var id: String = ""
+	var type: String = ""
+	var asset_id: String = ""
+	var position: Vector3 = Vector3.ZERO
+	var rotation: Vector4 = Vector4(0, 0, 0, 1)
+	var scale: Vector3 = Vector3.ONE
+	var properties: Dictionary = {}
+	var dynamic: bool = false
+	var flags: ContentFlags = ContentFlags.new()
+
+
+## The complete decoded chunk payload.
+class ChunkPayload:
+	var version: int = 1
+	var key: String = ""
+	var world_id: String = ""
+	var room_id: String = ""
+	var coord: Vector3i = Vector3i.ZERO
+	var bounds: AABB = AABB()
+	var tile_layers: Array[TileLayerData] = []
+	var objects: Array[WorldObjectData] = []
+	var flags: ContentFlags = ContentFlags.new()
+	var created_at: int = 0  # Unix timestamp
+	var updated_at: int = 0  # Unix timestamp
+	var revision: int = 0
+	var author: String = ""
+	var checksum: String = ""
+
+
+# ───────────────── Binary Decoding ─────────────────
+
+static var MAGIC := PackedByteArray([0x41, 0x47, 0x50, 0x43])  # "AGPC"
+const HEADER_SIZE: int = 48
+const SECTION_META: int = 0x01
+const SECTION_TILE: int = 0x02
+const SECTION_OBJECT: int = 0x03
+const SECTION_FLAGS: int = 0x04
+const SECTION_REVISION_META: int = 0x05
+
+
+## Decode a binary chunk payload into a ChunkPayload.
+## Returns null if the data is invalid or version is unsupported.
+static func decode_binary(data: PackedByteArray) -> ChunkPayload:
+	if data.size() < HEADER_SIZE:
+		push_error("ChunkDataDecoder: Data too short for header (%d bytes)" % data.size())
+		return null
+
+	# Verify magic
+	var magic := PackedByteArray(data.slice(0, 4))
+	if magic != MAGIC:
+		push_error("ChunkDataDecoder: Invalid magic bytes")
+		return null
+
+	# Read header fields
+	var version := _read_uint16(data, 4)
+	if version != 1:
+		push_error("ChunkDataDecoder: Unsupported chunk version %d" % version)
+		return null
+
+	var header_len := _read_uint16(data, 6)
+	var flags := _read_uint32(data, 8)
+	var payload_len := _read_uint32(data, 12)
+	var checksum := _read_hex_string(data, 16, 32)
+
+	# Verify payload length
+	if data.size() < HEADER_SIZE + payload_len:
+		push_error("ChunkDataDecoder: Payload too short")
+		return null
+
+	var payload := data.slice(HEADER_SIZE, HEADER_SIZE + payload_len)
+
+	# Verify checksum
+	var computed_checksum := _sha256_hex(payload)
+	if computed_checksum != checksum:
+		push_error("ChunkDataDecoder: Checksum mismatch")
+		# Continue anyway for resilience
+
+	var result := ChunkPayload.new()
+	result.version = version
+	result.checksum = checksum
+
+	# Parse sections
+	var offset := 0
+	while offset < payload.size():
+		if offset + 5 > payload.size():
+			break
+
+		var section_id := payload[offset]
+		var section_len := _read_uint32(payload, offset + 1)
+
+		if offset + 5 + section_len > payload.size():
+			break
+
+		var section_data := payload.slice(offset + 5, offset + 5 + section_len)
+
+		match section_id:
+			SECTION_META:
+				_parse_metadata_section(section_data, result)
+			SECTION_TILE:
+				_parse_tile_section(section_data, result)
+			SECTION_OBJECT:
+				_parse_object_section(section_data, result)
+			SECTION_FLAGS:
+				_parse_flags_section(section_data, result.flags)
+			SECTION_REVISION_META:
+				_parse_revision_meta_section(section_data, result)
+
+		offset += 5 + section_len
+
+	return result
+
+
+## Encode a ChunkPayload into binary format.
+static func encode_binary(payload: ChunkPayload) -> PackedByteArray:
+	var sections := PackedByteArray()
+
+	# Build metadata section
+	sections.append_array(_build_metadata_section(payload))
+	# Build tile sections
+	for layer in payload.tile_layers:
+		sections.append_array(_build_tile_section(layer))
+	# Build object sections
+	for obj in payload.objects:
+		sections.append_array(_build_object_section(obj))
+	# Build flags section
+	sections.append_array(_build_flags_section(payload.flags))
+	# Build revision meta section
+	sections.append_array(_build_revision_meta_section(payload))
+
+	var payload_bytes := PackedByteArray(sections)
+	var checksum := _sha256_hex(payload_bytes)
+
+	# Build header
+	var header := PackedByteArray()
+	header.append_array(MAGIC)
+	header.append_array(_write_uint16(1))  # version
+	header.append_array(_write_uint16(0))  # header_len (after this field)
+	header.append_array(_write_uint32(0))  # flags
+	header.append_array(_write_uint32(payload_bytes.size()))
+	header.append_array(_hex_to_bytes(checksum))
+
+	return header + payload_bytes
+
+
+# ───────────────── Section Parsers ─────────────────
+
+static func _parse_metadata_section(data: PackedByteArray, result: ChunkPayload) -> void:
+	var offset := 0
+
+	# world_id (length-prefixed string)
+	var world_id_len := _read_uint16(data, offset)
+	offset += 2
+	result.world_id = data.slice(offset, offset + world_id_len).get_string_from_utf8()
+	offset += world_id_len
+
+	# room_id (length-prefixed string)
+	var room_id_len := _read_uint16(data, offset)
+	offset += 2
+	result.room_id = data.slice(offset, offset + room_id_len).get_string_from_utf8()
+	offset += room_id_len
+
+	# coord (3 × int32)
+	result.coord = Vector3i(
+		_read_int32(data, offset),
+		_read_int32(data, offset + 4),
+		_read_int32(data, offset + 8)
+	)
+	offset += 12
+
+	# bounds (6 × float32)
+	var min_pos := Vector3(
+		_read_float32(data, offset),
+		_read_float32(data, offset + 4),
+		_read_float32(data, offset + 8)
+	)
+	var max_pos := Vector3(
+		_read_float32(data, offset + 12),
+		_read_float32(data, offset + 16),
+		_read_float32(data, offset + 20)
+	)
+	result.bounds = AABB(min_pos, max_pos - min_pos)
+
+
+static func _parse_tile_section(data: PackedByteArray, result: ChunkPayload) -> void:
+	var layer := TileLayerData.new()
+	var offset := 0
+
+	# name (length-prefixed string)
+	var name_len := _read_uint16(data, offset)
+	offset += 2
+	layer.name = data.slice(offset, offset + name_len).get_string_from_utf8()
+	offset += name_len
+
+	# layer_id (uint16)
+	layer.layer_id = _read_uint16(data, offset)
+	offset += 2
+
+	# dimensions (3 × uint16)
+	layer.width = _read_uint16(data, offset)
+	offset += 2
+	layer.height = _read_uint16(data, offset)
+	offset += 2
+	layer.depth = _read_uint16(data, offset)
+	offset += 2
+
+	# palette
+	var palette_count := _read_uint16(data, offset)
+	offset += 2
+	for _i in range(palette_count):
+		var tile_def := TileDef.new()
+		tile_def.id = _read_uint16(data, offset)
+		offset += 2
+
+		var asset_id_len := _read_uint16(data, offset)
+		offset += 2
+		tile_def.asset_id = data.slice(offset, offset + asset_id_len).get_string_from_utf8()
+		offset += asset_id_len
+
+		tile_def.solid = data[offset] != 0
+		offset += 1
+
+		tile_def.flags = _read_uint32(data, offset)
+		offset += 4
+
+		tile_def.variants = data[offset]
+		offset += 1
+
+		layer.palette.append(tile_def)
+
+	# tiles
+	var tile_count := _read_uint32(data, offset)
+	offset += 4
+	for i in range(tile_count):
+		layer.tiles.append(_read_uint16(data, offset))
+		offset += 2
+
+	result.tile_layers.append(layer)
+
+
+static func _parse_object_section(data: PackedByteArray, result: ChunkPayload) -> void:
+	var obj := WorldObjectData.new()
+	var offset := 0
+
+	# id (length-prefixed string)
+	var id_len := _read_uint16(data, offset)
+	offset += 2
+	obj.id = data.slice(offset, offset + id_len).get_string_from_utf8()
+	offset += id_len
+
+	# type (length-prefixed string)
+	var type_len := _read_uint16(data, offset)
+	offset += 2
+	obj.type = data.slice(offset, offset + type_len).get_string_from_utf8()
+	offset += type_len
+
+	# asset_id (length-prefixed string)
+	var asset_id_len := _read_uint16(data, offset)
+	offset += 2
+	obj.asset_id = data.slice(offset, offset + asset_id_len).get_string_from_utf8()
+	offset += asset_id_len
+
+	# position (3 × float32)
+	obj.position = Vector3(
+		_read_float32(data, offset),
+		_read_float32(data, offset + 4),
+		_read_float32(data, offset + 8)
+	)
+	offset += 12
+
+	# rotation (4 × float32)
+	obj.rotation = Vector4(
+		_read_float32(data, offset),
+		_read_float32(data, offset + 4),
+		_read_float32(data, offset + 8),
+		_read_float32(data, offset + 12)
+	)
+	offset += 16
+
+	# scale (3 × float32)
+	obj.scale = Vector3(
+		_read_float32(data, offset),
+		_read_float32(data, offset + 4),
+		_read_float32(data, offset + 8)
+	)
+	offset += 12
+
+	# dynamic (uint8)
+	obj.dynamic = data[offset] != 0
+	offset += 1
+
+	# properties (length-prefixed JSON string)
+	var props_len := _read_uint16(data, offset)
+	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 {}
+
+	# flags (ContentFlags)
+	obj.flags.violence = data[offset]
+	offset += 1
+	obj.flags.sexual = data[offset]
+	offset += 1
+	obj.flags.language = data[offset]
+	offset += 1
+	obj.flags.substance = data[offset]
+	offset += 1
+	obj.flags.gambling = data[offset]
+	offset += 1
+	obj.flags.horror = data[offset]
+	offset += 1
+	obj.flags.hate = data[offset]
+	offset += 1
+	obj.flags.custom = data[offset]
+	offset += 1
+	obj.flags.mature = data[offset] != 0
+	offset += 1
+
+	var source_count := _read_uint16(data, offset)
+	offset += 2
+	for _i in range(source_count):
+		var src_len := _read_uint16(data, offset)
+		offset += 2
+		obj.flags.sources.append(data.slice(offset, offset + src_len).get_string_from_utf8())
+		offset += src_len
+
+	result.objects.append(obj)
+
+
+static func _parse_flags_section(data: PackedByteArray, flags: ContentFlags) -> void:
+	flags.violence = data[0]
+	flags.sexual = data[1]
+	flags.language = data[2]
+	flags.substance = data[3]
+	flags.gambling = data[4]
+	flags.horror = data[5]
+	flags.hate = data[6]
+	flags.custom = data[7]
+	flags.mature = data[8] != 0
+
+	var offset := 9
+	var source_count := _read_uint16(data, offset)
+	offset += 2
+	for _i in range(source_count):
+		var src_len := _read_uint16(data, offset)
+		offset += 2
+		flags.sources.append(data.slice(offset, offset + src_len).get_string_from_utf8())
+		offset += src_len
+
+
+static func _parse_revision_meta_section(data: PackedByteArray, result: ChunkPayload) -> void:
+	var offset := 0
+	# created_at (int64 unix)
+	result.created_at = _read_int64(data, offset)
+	offset += 8
+	# updated_at (int64 unix)
+	result.updated_at = _read_int64(data, offset)
+	offset += 8
+	# revision (uint32)
+	result.revision = _read_uint32(data, offset)
+	offset += 4
+	# author (length-prefixed string)
+	var author_len := _read_uint16(data, offset)
+	offset += 2
+	result.author = data.slice(offset, offset + author_len).get_string_from_utf8()
+
+
+# ───────────────── Section Builders ─────────────────
+
+static func _build_metadata_section(payload: ChunkPayload) -> PackedByteArray:
+	var data := PackedByteArray()
+	data.append_array(_write_string(payload.world_id))
+	data.append_array(_write_string(payload.room_id))
+	data.append_array(_write_int32(payload.coord.x))
+	data.append_array(_write_int32(payload.coord.y))
+	data.append_array(_write_int32(payload.coord.z))
+	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(payload.bounds.size.y))
+	data.append_array(_write_float32(payload.bounds.size.z))
+	return data
+
+
+static func _build_tile_section(layer: TileLayerData) -> PackedByteArray:
+	var data := PackedByteArray()
+	data.append_array(_write_string(layer.name))
+	data.append_array(_write_uint16(layer.layer_id))
+	data.append_array(_write_uint16(layer.width))
+	data.append_array(_write_uint16(layer.height))
+	data.append_array(_write_uint16(layer.depth))
+	data.append_array(_write_uint16(layer.palette.size()))
+
+	for tile_def in layer.palette:
+		data.append_array(_write_uint16(tile_def.id))
+		data.append_array(_write_string(tile_def.asset_id))
+		data.append(tile_def.solid as int)
+		data.append_array(_write_uint32(tile_def.flags))
+		data.append(tile_def.variants)
+
+	data.append_array(_write_uint32(layer.tiles.size()))
+	for tile_id in layer.tiles:
+		data.append_array(_write_uint16(tile_id))
+
+	return _wrap_section(data, SECTION_TILE)
+
+
+static func _build_object_section(obj: WorldObjectData) -> PackedByteArray:
+	var data := PackedByteArray()
+	data.append_array(_write_string(obj.id))
+	data.append_array(_write_string(obj.type))
+	data.append_array(_write_string(obj.asset_id))
+	data.append_array(_write_float32(obj.position.x))
+	data.append_array(_write_float32(obj.position.y))
+	data.append_array(_write_float32(obj.position.z))
+	data.append_array(_write_float32(obj.rotation.x))
+	data.append_array(_write_float32(obj.rotation.y))
+	data.append_array(_write_float32(obj.rotation.z))
+	data.append_array(_write_float32(obj.rotation.w))
+	data.append_array(_write_float32(obj.scale.x))
+	data.append_array(_write_float32(obj.scale.y))
+	data.append_array(_write_float32(obj.scale.z))
+	data.append(obj.dynamic as int)
+
+	var props_json := JSON.stringify(obj.properties, "  ")
+	data.append_array(_write_string(props_json))
+
+	data.append(obj.flags.violence)
+	data.append(obj.flags.sexual)
+	data.append(obj.flags.language)
+	data.append(obj.flags.substance)
+	data.append(obj.flags.gambling)
+	data.append(obj.flags.horror)
+	data.append(obj.flags.hate)
+	data.append(obj.flags.custom)
+	data.append(obj.flags.mature as int)
+	data.append_array(_write_uint16(obj.flags.sources.size()))
+	for src in obj.flags.sources:
+		data.append_array(_write_string(src))
+
+	return _wrap_section(data, SECTION_OBJECT)
+
+
+static func _build_flags_section(flags: ContentFlags) -> PackedByteArray:
+	var data := PackedByteArray()
+	data.append(flags.violence)
+	data.append(flags.sexual)
+	data.append(flags.language)
+	data.append(flags.substance)
+	data.append(flags.gambling)
+	data.append(flags.horror)
+	data.append(flags.hate)
+	data.append(flags.custom)
+	data.append(flags.mature as int)
+	data.append_array(_write_uint16(flags.sources.size()))
+	for src in flags.sources:
+		data.append_array(_write_string(src))
+	return _wrap_section(data, SECTION_FLAGS)
+
+
+static func _build_revision_meta_section(payload: ChunkPayload) -> PackedByteArray:
+	var data := PackedByteArray()
+	data.append_array(_write_int64(payload.created_at))
+	data.append_array(_write_int64(payload.updated_at))
+	data.append_array(_write_uint32(payload.revision))
+	data.append_array(_write_string(payload.author))
+	return _wrap_section(data, SECTION_REVISION_META)
+
+
+static func _wrap_section(data: PackedByteArray, section_id: int) -> PackedByteArray:
+	var wrapped := PackedByteArray()
+	wrapped.append(section_id)
+	wrapped.append_array(_write_uint32(data.size()))
+	wrapped.append_array(data)
+	return wrapped
+
+
+# ───────────────── Binary Helpers ─────────────────
+
+static func _read_uint16(data: PackedByteArray, offset: int) -> int:
+	return data[offset] | (data[offset + 1] << 8)
+
+static func _read_uint32(data: PackedByteArray, offset: int) -> int:
+	return (data[offset] | (data[offset + 1] << 8) |
+	        (data[offset + 2] << 16) | (data[offset + 3] << 24))
+
+static func _read_int32(data: PackedByteArray, offset: int) -> int:
+	var val := _read_uint32(data, offset)
+	if val >= 0x80000000:
+		return val - 0x100000000
+	return val
+
+static func _read_int64(data: PackedByteArray, offset: int) -> int:
+	var lo := _read_uint32(data, offset)
+	var hi := _read_uint32(data, offset + 4)
+	return hi * 0x100000000 + lo
+
+static func _read_float32(data: PackedByteArray, offset: int) -> float:
+	var bits := _read_uint32(data, offset)
+	return bits as float  # GDScript float is 64-bit; bits repr works for IEEE 754
+
+static func _read_hex_string(data: PackedByteArray, offset: int, length: int) -> String:
+	var hex_chars := "0123456789abcdef"
+	var result := ""
+	for i in range(length):
+		var byte_val := data[offset + i]
+		result += hex_chars[byte_val >> 4]
+		result += hex_chars[byte_val & 0x0F]
+	return result
+
+
+static func _write_uint16(val: int) -> PackedByteArray:
+	return PackedByteArray([(val & 0xFF), (val >> 8) & 0xFF])
+
+static func _write_uint32(val: int) -> PackedByteArray:
+	return PackedByteArray([
+		val & 0xFF, (val >> 8) & 0xFF, (val >> 16) & 0xFF, (val >> 24) & 0xFF
+	])
+
+static func _write_int32(val: int) -> PackedByteArray:
+	return _write_uint32(val)
+
+static func _write_int64(val: int) -> PackedByteArray:
+	var lo := val & 0xFFFFFFFF
+	var hi := (val >> 32) & 0xFFFFFFFF
+	return _write_uint32(lo) + _write_uint32(hi)
+
+static func _write_float32(val: float) -> PackedByteArray:
+	var bits := val as int
+	return _write_uint32(bits)
+
+static func _write_string(s: String) -> PackedByteArray:
+	var bytes := s.to_utf8_buffer()
+	return _write_uint16(bytes.size()) + bytes
+
+static func _hex_to_bytes(hex_str: String) -> PackedByteArray:
+	var result := PackedByteArray()
+	for i in range(0, hex_str.length(), 2):
+		var byte_val := ("0x" + hex_str.substr(i, 2)).hex_to_int()
+		result.append(byte_val)
+	return result
+
+
+# ───────────────── SHA-256 ─────────────────
+
+static func _sha256_hex(data: PackedByteArray) -> String:
+	var ctx := HashingContext.new()
+	ctx.start(HashingContext.HASH_SHA256)
+	ctx.update(data)
+	var hash := ctx.finish()
+	var hex_chars := "0123456789abcdef"
+	var result := ""
+	for byte_val in hash:
+		result += hex_chars[(byte_val >> 4) & 0x0F]
+		result += hex_chars[byte_val & 0x0F]
+	return result

scripts/chunk_data_decoder.gd.uid

@@ -0,0 +1 @@
+uid://bv445xrd6f5tk

scripts/chunk_scene.gd

@@ -0,0 +1,170 @@
+class_name ChunkScene
+extends Node3D
+## A visual representation of a single loaded world chunk.
+##
+## This node is instantiated by [ChunkStreamManager] when a chunk is loaded.
+## It holds the tile layers, world objects, and metadata for one chunk of the
+## world. The scene is responsible for rendering the chunk's visual content
+## and exposing its gameplay objects to the rest of the game.
+##
+## ## Structure
+##
+## ```
+## ChunkScene (Node3D)
+##  ├── TileLayer (Node3D)  # one per tile layer (ground, walls, decor, ...)
+##  ├── StaticObject (Node3D)  # props, geometry, interactables
+##  └── DynamicObject (Node3D)  # spawnable entities (templates)
+## ```
+##
+## ## Lifecycle
+##
+## 1. [ChunkStreamManager] requests chunk data from the server.
+## 2. Server responds with binary payload.
+## 3. [ChunkStreamManager] decodes the payload and creates a [ChunkScene].
+## 4. [ChunkScene] populates itself with tile layers and objects.
+## 5. When the player moves out of range, [ChunkStreamManager] calls
+##    [method ChunkScene.queue_free] to unload it.
+
+## The chunk coordinate this scene represents.
+var coord: Vector3i = Vector3i.ZERO
+
+## The canonical chunk key.
+var key: String = ""
+
+## World-space bounding box of this chunk.
+var bounds: AABB = AABB()
+
+## Format version of the chunk data.
+var format_version: int = 1
+
+## Revision counter from the server.
+var revision: int = 0
+
+## List of tile layers in this chunk.
+var tile_layers: Array[TileLayer] = []
+
+## List of world objects (static + dynamic) in this chunk.
+var world_objects: Array[WorldObject] = []
+
+## Content moderation flags for this chunk.
+var content_flags: ChunkDataDecoder.ContentFlags = ChunkDataDecoder.ContentFlags.new()
+
+## Whether this chunk has been modified locally (not yet synced to server).
+var is_dirty: bool = false
+
+
+func _ready() -> void:
+	# Position this chunk scene at its world-space origin
+	global_position = bounds.position
+	# Set up collision shape for the chunk bounds
+	_setup_collision()
+
+
+func _setup_collision() -> void:
+	# Add a collision shape for the chunk's bounding box
+	var collision := CollisionShape3D.new()
+	var shape := BoxShape3D.new()
+	shape.size = bounds.size
+	collision.shape = shape
+	collision.name = "ChunkBounds"
+	add_child(collision)
+
+
+## Add a tile layer to this chunk scene.
+func add_tile_layer(layer: TileLayer) -> void:
+	tile_layers.append(layer)
+	var layer_node := TileLayerNode.new()
+	layer_node.tile_layer = layer
+	layer_node.chunk_coord = coord
+	add_child(layer_node)
+
+
+## Add a world object to this chunk scene.
+func add_object(obj: WorldObject) -> void:
+	world_objects.append(obj)
+	if obj.is_dynamic:
+		_add_dynamic_object(obj)
+	else:
+		_add_static_object(obj)
+
+
+func _add_static_object(obj: WorldObject) -> void:
+	var static_obj := StaticObjectNode.new()
+	static_obj.world_object = obj
+	static_obj.position = obj.position
+	static_obj.quaternion = Quaternion(obj.rotation.x, obj.rotation.y, obj.rotation.z, obj.rotation.w)
+	static_obj.scale = obj.scale
+	static_obj.name = "static_%s" % obj.id
+	add_child(static_obj)
+
+
+func _add_dynamic_object(obj: WorldObject) -> void:
+	var dynamic_obj := DynamicObjectNode.new()
+	dynamic_obj.world_object = obj
+	dynamic_obj.position = obj.position
+	dynamic_obj.quaternion = Quaternion(obj.rotation.x, obj.rotation.y, obj.rotation.z, obj.rotation.w)
+	dynamic_obj.scale = obj.scale
+	dynamic_obj.name = "dynamic_%s" % obj.id
+	add_child(dynamic_obj)
+
+
+## Get a world object by its ID.
+func get_object_by_id(object_id: String) -> WorldObject:
+	for obj in world_objects:
+		if obj.id == object_id:
+			return obj
+	return null
+
+
+## Get all static objects in this chunk.
+func get_static_objects() -> Array[WorldObject]:
+	var result: Array[WorldObject] = []
+	for obj in world_objects:
+		if not obj.is_dynamic:
+			result.append(obj)
+	return result
+
+
+## Get all dynamic object templates in this chunk.
+func get_dynamic_templates() -> Array[WorldObject]:
+	var result: Array[WorldObject] = []
+	for obj in world_objects:
+		if obj.is_dynamic:
+			result.append(obj)
+	return result
+
+
+## Mark this chunk as dirty (locally modified).
+func mark_dirty() -> void:
+	is_dirty = true
+
+
+## Clear all objects and tile layers from this chunk.
+func clear() -> void:
+	for child in get_children():
+		if child is TileLayerNode or child is StaticObjectNode or child is DynamicObjectNode:
+			child.queue_free()
+	tile_layers.clear()
+	world_objects.clear()
+
+
+## Get the world-space position of a tile within this chunk.
+func get_tile_world_position(tile_x: int, tile_y: int, tile_z: int = 0) -> Vector3:
+	return bounds.position + Vector3(
+		tile_x * 1.0,  # Tile size is 1 world unit
+		tile_y * 1.0,
+		tile_z * 1.0
+	)
+
+
+## Check if a world-space position is within this chunk's bounds.
+func contains_position(pos: Vector3) -> bool:
+	return bounds.has_point(pos)
+
+
+## Check if a chunk coordinate is adjacent to this chunk.
+func is_adjacent(other_coord: Vector3i) -> bool:
+	var dx: int = abs(coord.x - other_coord.x)
+	var dy: int = abs(coord.y - other_coord.y)
+	var dz: int = abs(coord.z - other_coord.z)
+	return dx <= 1 and dy <= 1 and dz <= 1 and (dx + dy + dz) > 0

scripts/chunk_scene.gd.uid

@@ -0,0 +1 @@
+uid://d4gh4h5iey6xb

scripts/chunk_stream_manager.gd

@@ -0,0 +1,358 @@
+class_name ChunkStreamManager
+extends Node
+## Manages loading and unloading of world chunks based on player position.
+##
+## This is the central orchestrator for the chunk streaming system. It monitors
+## the player's position, determines which chunks should be loaded, requests
+## chunk data from the server, instantiates ChunkScene nodes, and unloads
+## chunks that fall outside the streaming radius.
+##
+## ## Design
+##
+## - **Streaming radius** defines how many chunks around the player are kept
+##   loaded. Chunks beyond this radius are unloaded to save memory and CPU.
+## - **Load priority** ensures chunks closer to the player are loaded first,
+##   preventing visual pop-in at the edge of the view.
+## - **Server communication** uses the RPCs defined in docs/architecture/world.md
+##   (§5.3): `request_chunk`, `chunk_data`, `chunk_invalidated`.
+##
+## ## Usage
+##
+## Add this node to your scene tree and set the `player` reference:
+## ```gdscript
+## var stream_manager: ChunkStreamManager = $ChunkStreamManager
+## stream_manager.player = $Player
+## stream_manager.streaming_radius = 4  # chunks
+## ```
+
+## Number of chunks (radius) to keep loaded around the player.
+## A radius of 2 means a 5x5 grid of chunks centered on the player.
+## Higher values increase memory usage but reduce streaming pop-in.
+@export var streaming_radius: int = 3
+
+## Maximum number of chunks to load per frame. Prevents frame spikes during
+## rapid movement or when entering a new area.
+@export var max_loads_per_frame: int = 4
+
+## Maximum number of chunks to unload per frame.
+@export var max_unloads_per_frame: int = 4
+
+## Distance (in chunks) from the streaming radius edge before a chunk is
+## considered for unloading. Prevents rapid load/unload cycling.
+@export var unload_margin: int = 1
+
+## Emitted when a chunk finishes loading.
+signal chunk_loaded(chunk_coord: Vector3i, chunk_scene: Node)
+
+## Emitted when a chunk is unloaded.
+signal chunk_unloaded(chunk_coord: Vector3i)
+
+## Emitted when a chunk fails to load (e.g., server error).
+signal chunk_load_failed(chunk_coord: Vector3i, error: String)
+
+## Emitted when the player moves far enough to require a streaming update.
+signal streaming_updated
+
+## Reference to the player node. Must be set before the manager starts.
+var player: Node3D = null
+
+## The current player chunk coordinate.
+var _player_chunk_coord: Vector3i = Vector3i.ZERO
+
+## Map of loaded chunk coordinates to their scene nodes.
+var _loaded_chunks: Dictionary = {}
+
+## Queue of chunk coordinates pending load, sorted by distance from player.
+var _load_queue: Array[Vector3i] = []
+
+## Queue of chunk coordinates pending unload.
+var _unload_queue: Array[Vector3i] = []
+
+## Whether streaming is currently active (player is set and in game).
+var is_active: bool = false
+
+## The server RPC interface for chunk data. Set by the networking layer.
+var _server_rpc: Object = null
+
+## Internal: track which chunks are currently being loaded (to avoid duplicates).
+var _loading_in_progress: Dictionary = {}
+
+## Internal: time accumulator for throttled streaming updates.
+var _update_accumulator: float = 0.0
+
+## Internal: interval between streaming updates (seconds).
+const UPDATE_INTERVAL: float = 0.1
+
+
+func _ready() -> void:
+	# Streaming is driven from _process (main thread) so we can safely
+	# manipulate the scene tree. No background thread is used.
+	set_process(true)
+
+
+func _process(delta: float) -> void:
+	if not is_active or player == null:
+		return
+
+	_update_accumulator += delta
+	if _update_accumulator < UPDATE_INTERVAL:
+		return
+	_update_accumulator = 0.0
+
+	_update_streaming()
+	_process_load_queue()
+	_process_unload_queue()
+	streaming_updated.emit()
+
+
+func _update_streaming() -> void:
+	if player == null or not is_inside_tree():
+		return
+
+	var current_coord: Vector3i = Chunk.coord_for_position(player.global_position)
+	if current_coord == _player_chunk_coord:
+		return
+
+	_player_chunk_coord = current_coord
+	_rebuild_queues()
+
+
+func _rebuild_queues() -> void:
+	var target_set: Dictionary = _compute_target_chunks()
+
+	# Determine which chunks need to be loaded
+	var to_load: Array[Vector3i] = []
+	for coord in target_set:
+		if not _loaded_chunks.has(coord) and not _loading_in_progress.has(coord):
+			to_load.append(coord)
+
+	# Sort by distance from player (closest first)
+	to_load.sort_custom(_compare_distance)
+	_load_queue = to_load
+
+	# Determine which chunks need to be unloaded
+	var to_unload: Array[Vector3i] = []
+	for coord in _loaded_chunks:
+		if not target_set.has(coord):
+			to_unload.append(coord)
+
+	to_unload.sort_custom(_compare_distance)
+	_unload_queue = to_unload
+
+
+func _compute_target_chunks() -> Dictionary:
+	"""Compute the set of chunk coordinates that should be loaded."""
+	var target: Dictionary = {}
+	var half: int = streaming_radius
+	for dx in range(-half, half + 1):
+		for dy in range(-half, half + 1):
+			for dz in range(-half, half + 1):
+				var coord: Vector3i = Vector3i(
+					_player_chunk_coord.x + dx,
+					_player_chunk_coord.y + dy,
+					_player_chunk_coord.z + dz
+				)
+				target[coord] = coord
+	return target
+
+
+func _compare_distance(a: Vector3i, b: Vector3i) -> bool:
+	"""Compare chunk coordinates by distance from player chunk."""
+	var dist_a: int = _chunk_distance_squared(_player_chunk_coord, a)
+	var dist_b: int = _chunk_distance_squared(_player_chunk_coord, b)
+	return dist_a < dist_b
+
+
+func _chunk_distance_squared(a: Vector3i, b: Vector3i) -> int:
+	var dx: int = a.x - b.x
+	var dy: int = a.y - b.y
+	var dz: int = a.z - b.z
+	return dx * dx + dy * dy + dz * dz
+
+
+func _process_load_queue() -> void:
+	var count: int = 0
+	while count < max_loads_per_frame and not _load_queue.is_empty():
+		var coord: Vector3i = _load_queue.pop_front()
+		_load_chunk(coord)
+		count += 1
+
+
+func _process_unload_queue() -> void:
+	var count: int = 0
+	while count < max_unloads_per_frame and not _unload_queue.is_empty():
+		var coord: Vector3i = _unload_queue.pop_front()
+		_unload_chunk(coord)
+		count += 1
+
+
+func _load_chunk(coord: Vector3i) -> void:
+	if _loading_in_progress.has(coord):
+		return
+
+	_loading_in_progress[coord] = true
+
+	# Request chunk data from server via RPC
+	if _server_rpc != null and _server_rpc.has_method("request_chunk"):
+		_server_rpc.request_chunk(Chunk.build_key(
+			"", "", coord
+		))
+	else:
+		# Fallback: try to load from local cache or create empty chunk
+		_instantiate_chunk_scene(coord)
+
+
+func _on_chunk_data_received(key: String, binary_data: PackedByteArray) -> void:
+	"""Called by the networking layer when chunk data arrives from server."""
+	var coord: Vector3i = _parse_coord_from_key(key)
+	if coord == null:
+		return
+
+	_loading_in_progress.erase(coord)
+
+	# Decode the binary chunk data
+	var chunk_data: ChunkDataDecoder.ChunkPayload = ChunkDataDecoder.decode_binary(binary_data)
+	if chunk_data == null:
+		chunk_load_failed.emit(coord, "Failed to decode chunk data")
+		return
+
+	# Instantiate the chunk scene with the decoded data
+	_instantiate_chunk_scene_with_data(coord, chunk_data)
+
+
+func _on_chunk_load_error(coord: Vector3i, error_msg: String) -> void:
+	"""Called when the server reports a chunk load error."""
+	_loading_in_progress.erase(coord)
+	chunk_load_failed.emit(coord, error_msg)
+
+
+func _instantiate_chunk_scene(coord: Vector3i) -> void:
+	"""Create an empty chunk scene for the given coordinate."""
+	var chunk_scene: ChunkScene = ChunkScene.new()
+	chunk_scene.coord = coord
+	chunk_scene.key = Chunk.build_key("", "", coord)
+	chunk_scene.bounds = Chunk.compute_bounds(coord)
+	_add_loaded_chunk(coord, chunk_scene)
+
+
+func _instantiate_chunk_scene_with_data(coord: Vector3i, data: ChunkDataDecoder.ChunkPayload) -> void:
+	"""Create a chunk scene populated with server data."""
+	var chunk_scene: ChunkScene = ChunkScene.new()
+	chunk_scene.coord = coord
+	chunk_scene.key = data.key
+	chunk_scene.bounds = data.bounds
+	chunk_scene.format_version = data.format_version
+	chunk_scene.revision = data.revision
+
+	# Add tiles
+	for layer in data.tile_layers:
+		var tile_layer: TileLayer = TileLayer.new()
+		tile_layer.name = layer.name
+		tile_layer.layer_id = layer.layer_id
+		tile_layer.width = layer.width
+		tile_layer.height = layer.height
+		tile_layer.depth = layer.depth
+		tile_layer.palette = layer.palette
+		tile_layer.tiles = layer.tiles
+		chunk_scene.add_tile_layer(tile_layer)
+
+	# Add objects
+	for obj_data in data.objects:
+		var world_obj: WorldObject = WorldObject.new()
+		world_obj.id = obj_data.id
+		world_obj.type = obj_data.type
+		world_obj.asset_id = obj_data.asset_id
+		world_obj.position = obj_data.position
+		world_obj.rotation = obj_data.rotation
+		world_obj.scale = obj_data.scale
+		world_obj.properties = obj_data.properties
+		world_obj.is_dynamic = obj_data.dynamic
+		world_obj.flags = obj_data.flags
+		chunk_scene.add_object(world_obj)
+
+	# Add content flags
+	chunk_scene.content_flags = data.flags
+
+	_add_loaded_chunk(coord, chunk_scene)
+
+
+func _add_loaded_chunk(coord: Vector3i, chunk_scene: Node) -> void:
+	_loaded_chunks[coord] = chunk_scene
+	add_child(chunk_scene)
+	_loading_in_progress.erase(coord)
+	chunk_loaded.emit(coord, chunk_scene)
+
+
+func _unload_chunk(coord: Vector3i) -> void:
+	if not _loaded_chunks.has(coord):
+		return
+
+	var chunk_scene: Node = _loaded_chunks[coord]
+	if is_instance_valid(chunk_scene):
+		chunk_scene.queue_free()
+
+	_loaded_chunks.erase(coord)
+	chunk_unloaded.emit(coord)
+
+
+func _on_player_position_changed() -> void:
+	"""Call this when the player position changes significantly."""
+	if player != null:
+		_update_streaming()
+
+
+func set_server_rpc(rpc_interface: Object) -> void:
+	"""Set the server RPC interface for chunk requests."""
+	_server_rpc = rpc_interface
+
+
+func get_loaded_chunk(coord: Vector3i) -> Node:
+	"""Get a loaded chunk scene by coordinate, or null if not loaded."""
+	return _loaded_chunks.get(coord, null)
+
+
+func is_chunk_loaded(coord: Vector3i) -> bool:
+	"""Check if a chunk is currently loaded."""
+	return _loaded_chunks.has(coord)
+
+
+func get_loaded_chunk_count() -> int:
+	"""Get the number of currently loaded chunks."""
+	return _loaded_chunks.size()
+
+
+func get_all_loaded_coords() -> Array[Vector3i]:
+	"""Get all currently loaded chunk coordinates."""
+	var coords: Array[Vector3i] = []
+	for key in _loaded_chunks:
+		coords.append(key)
+	return coords
+
+
+func force_reload_chunk(coord: Vector3i) -> void:
+	"""Force reload a specific chunk (e.g., after server update)."""
+	if _loaded_chunks.has(coord):
+		_unload_chunk(coord)
+	if not _loading_in_progress.has(coord):
+		_load_chunk(coord)
+
+
+func clear_all_chunks() -> void:
+	"""Unload all chunks immediately."""
+	var coords: Array[Vector3i] = get_all_loaded_coords()
+	for coord in coords:
+		_unload_chunk(coord)
+	_load_queue.clear()
+	_unload_queue.clear()
+
+
+func _parse_coord_from_key(key: String) -> Variant:
+	"""Parse chunk coordinate from a canonical chunk key."""
+	var parts: Array[String] = key.split(":")
+	if parts.size() < 5:
+		return null
+	return Vector3i(
+		int(parts[2]),
+		int(parts[3]),
+		int(parts[4])
+	)

scripts/chunk_stream_manager.gd.uid

@@ -0,0 +1 @@
+uid://8yokqwe23c23

scripts/dynamic_object_node.gd

@@ -0,0 +1,68 @@
+class_name DynamicObjectNode
+extends Node3D
+## A visual representation of a dynamic (spawnable) world object template.
+##
+## This node is instantiated by [ChunkScene] for each dynamic [WorldObject].
+## Dynamic objects are stored as *templates* in the chunk; their runtime state
+## (position, health, inventory) is managed by the entity system, not by this
+## node. This node renders the template's visual representation so the object
+## is visible in the world.
+##
+## ## Structure
+##
+## ```
+## DynamicObjectNode (Node3D)
+##  └── MeshInstance3D  # the object's visual mesh
+## ```
+
+## The world object data this node represents.
+var world_object: WorldObject = null
+
+## The loaded mesh instance (or placeholder).
+var _mesh_instance: MeshInstance3D = null
+
+
+func _ready() -> void:
+	if world_object == null:
+		return
+	_load_mesh()
+
+
+## Load and attach the object's mesh.
+func _load_mesh() -> void:
+	_mesh_instance = MeshInstance3D.new()
+	_mesh_instance.name = "mesh"
+
+	var mesh := _load_asset_mesh(world_object.asset_id)
+	if mesh == null:
+		mesh = _make_placeholder_mesh()
+
+	_mesh_instance.mesh = mesh
+	add_child(_mesh_instance)
+
+
+## Attempt to load a mesh from the asset path.
+func _load_asset_mesh(asset_id: String) -> Mesh:
+	if asset_id.is_empty():
+		return null
+	var path := "res://assets/%s" % asset_id
+	if ResourceLoader.exists(path):
+		var res := load(path)
+		if res is Mesh:
+			return res
+	return null
+
+
+## Create a simple placeholder sphere mesh when the real asset is unavailable.
+func _make_placeholder_mesh() -> Mesh:
+	var mesh := SphereMesh.new()
+	mesh.radius = 0.5
+	mesh.height = 1.0
+	return mesh
+
+
+## Get the world object's display name.
+func get_display_name() -> String:
+	if world_object == null:
+		return ""
+	return world_object.get_display_name()

scripts/dynamic_object_node.gd.uid

@@ -0,0 +1 @@
+uid://dyjqcstdnr4u1

scripts/static_object_node.gd

@@ -0,0 +1,67 @@
+class_name StaticObjectNode
+extends Node3D
+## A visual representation of a static world object within a chunk.
+##
+## This node is instantiated by [ChunkScene] for each static (non-dynamic)
+## [WorldObject]. It renders the object's mesh (referenced by `asset_id`) at
+## the object's transform. If the asset is not yet loaded, a placeholder mesh
+## is shown.
+##
+## ## Structure
+##
+## ```
+## StaticObjectNode (Node3D)
+##  └── MeshInstance3D  # the object's visual mesh
+## ```
+
+## The world object data this node represents.
+var world_object: WorldObject = null
+
+## The loaded mesh instance (or placeholder).
+var _mesh_instance: MeshInstance3D = null
+
+
+func _ready() -> void:
+	if world_object == null:
+		return
+	_load_mesh()
+
+
+## Load and attach the object's mesh.
+func _load_mesh() -> void:
+	_mesh_instance = MeshInstance3D.new()
+	_mesh_instance.name = "mesh"
+
+	# Try to load the asset by its id (path). Fall back to a placeholder.
+	var mesh := _load_asset_mesh(world_object.asset_id)
+	if mesh == null:
+		mesh = _make_placeholder_mesh()
+
+	_mesh_instance.mesh = mesh
+	add_child(_mesh_instance)
+
+
+## Attempt to load a mesh from the asset path.
+func _load_asset_mesh(asset_id: String) -> Mesh:
+	if asset_id.is_empty():
+		return null
+	var path := "res://assets/%s" % asset_id
+	if ResourceLoader.exists(path):
+		var res := load(path)
+		if res is Mesh:
+			return res
+	return null
+
+
+## Create a simple placeholder box mesh when the real asset is unavailable.
+func _make_placeholder_mesh() -> Mesh:
+	var mesh := BoxMesh.new()
+	mesh.size = Vector3(1.0, 1.0, 1.0)
+	return mesh
+
+
+## Get the world object's display name.
+func get_display_name() -> String:
+	if world_object == null:
+		return ""
+	return world_object.get_display_name()

scripts/static_object_node.gd.uid

@@ -0,0 +1 @@
+uid://chf6mruev1kc4

scripts/tile_def.gd

@@ -0,0 +1,42 @@
+class_name TileDef
+extends RefCounted
+## A single tile definition (palette entry) within a tile layer.
+##
+## Maps a tile ID to its asset reference and gameplay flags. See
+## docs/architecture/world.md §3.2.
+
+## Tile ID (index into the layer palette). 0 is reserved for empty/air.
+var id: int = 0
+
+## Reference to the tile/terrain asset.
+var asset_id: String = ""
+
+## Whether this tile has collision.
+var solid: bool = false
+
+## Bitmask flags: bit 0 = walkable, bit 1 = climbable, bit 2 = liquid.
+var flags: int = 0
+
+## Number of visual variants for this tile.
+var variants: int = 1
+
+
+func _init(p_id: int = 0, p_asset_id: String = "", p_solid: bool = false,
+		p_flags: int = 0, p_variants: int = 1) -> void:
+	id = p_id
+	asset_id = p_asset_id
+	solid = p_solid
+	flags = p_flags
+	variants = p_variants
+
+
+func is_walkable() -> bool:
+	return (flags & 0x01) != 0
+
+
+func is_climbable() -> bool:
+	return (flags & 0x02) != 0
+
+
+func is_liquid() -> bool:
+	return (flags & 0x04) != 0

scripts/tile_def.gd.uid

@@ -0,0 +1 @@
+uid://bavmpbmthilbx

scripts/tile_layer.gd

@@ -0,0 +1,83 @@
+class_name TileLayer
+extends RefCounted
+## A single tile layer within a chunk.
+##
+## Holds the dense grid of tile IDs, the palette mapping tile IDs to tile
+## definitions, and the layer metadata. This is the runtime representation of
+## the `TileLayer` from the chunk data format (see docs/architecture/world.md
+## §3.2).
+
+## Layer name (e.g. "ground", "walls", "decor").
+var name: String = ""
+
+## Numeric layer id, unique within the chunk.
+var layer_id: int = 0
+
+## Grid dimensions in tiles.
+var width: int = 0
+var height: int = 0
+var depth: int = 1
+
+## Palette mapping tile IDs to tile definitions (shared per layer).
+var palette: Array[TileDef] = []
+
+## Dense, row-major tile IDs. Length = width * height * depth.
+var tiles: PackedInt32Array = PackedInt32Array()
+
+
+func _init(
+	p_layer_name: String = "",
+	p_layer_id: int = 0,
+	p_width: int = 0,
+	p_height: int = 0,
+	p_depth: int = 1
+) -> void:
+	name = p_layer_name
+	layer_id = p_layer_id
+	width = p_width
+	height = p_height
+	depth = p_depth
+
+
+## Total number of tiles in this layer.
+func tile_count() -> int:
+	return width * height * depth
+
+
+## Get the tile ID at (x, y, z). Returns 0 (empty) for out-of-bounds.
+func get_tile(x: int, y: int, z: int = 0) -> int:
+	if x < 0 or x >= width or y < 0 or y >= height or z < 0 or z >= depth:
+		return 0
+	var idx := (z * height + y) * width + x
+	if idx < tiles.size():
+		return tiles[idx]
+	return 0
+
+
+## Set the tile ID at (x, y, z). No-op if out of bounds.
+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
+
+
+## Get the tile definition for a tile ID, or null if not in the palette.
+func get_tile_def(tile_id: int) -> TileDef:
+	for def in palette:
+		if def.id == tile_id:
+			return def
+	return null
+
+
+## Whether the tile at (x, y, z) is solid (collision).
+func is_solid(x: int, y: int, z: int = 0) -> bool:
+	var def := get_tile_def(get_tile(x, y, z))
+	return def != null and def.solid
+
+
+## Whether the tile at (x, y, z) is walkable.
+func is_walkable(x: int, y: int, z: int = 0) -> bool:
+	var def := get_tile_def(get_tile(x, y, z))
+	return def != null and def.is_walkable()

scripts/tile_layer.gd.uid

@@ -0,0 +1 @@
+uid://came2ygke3ajs

scripts/tile_layer_node.gd

@@ -0,0 +1,112 @@
+class_name TileLayerNode
+extends Node3D
+## A visual representation of a single tile layer within a chunk.
+##
+## This node is instantiated by [ChunkScene] for each tile layer in a chunk.
+## It renders the layer's tiles as instanced meshes (one per tile definition
+## in the palette) using [MultiMeshInstance3D] for efficiency.
+##
+## ## Structure
+##
+## ```
+## TileLayerNode (Node3D)
+##  └── MultiMeshInstance3D  # one per palette entry (tile definition)
+## ```
+
+## The tile layer data this node renders.
+var tile_layer: TileLayer = null
+
+## The chunk coordinate this layer belongs to (for world positioning).
+var chunk_coord: Vector3i = Vector3i.ZERO
+
+## Tile size in world units (each tile is 1x1x1).
+const TILE_SIZE: float = 1.0
+
+## Cache of MultiMeshInstance3D nodes, keyed by tile definition id.
+var _mesh_instances: Dictionary = {}
+
+
+func _ready() -> void:
+	if tile_layer == null:
+		return
+	_build_meshes()
+
+
+## Build the MultiMesh instances for each tile definition in the palette.
+func _build_meshes() -> void:
+	for tile_def in tile_layer.palette:
+		if tile_def.id == 0:
+			continue  # Tile 0 is "empty/air", no mesh needed
+		_create_mesh_for_tile(tile_def)
+
+
+func _create_mesh_for_tile(tile_def: TileDef) -> void:
+	# Count how many cells use this tile definition
+	var count := 0
+	for tile_id in tile_layer.tiles:
+		if tile_id == tile_def.id:
+			count += 1
+
+	if count == 0:
+		return
+
+	var multi_mesh := MultiMesh.new()
+	multi_mesh.transform_format = MultiMesh.TRANSFORM_3D
+	multi_mesh.mesh = _make_unit_cube_mesh()
+	multi_mesh.instance_count = count
+
+	var instance_idx := 0
+	for z in range(tile_layer.depth):
+		for y in range(tile_layer.height):
+			for x in range(tile_layer.width):
+				var tile_id := tile_layer.get_tile(x, y, z)
+				if tile_id != tile_def.id:
+					continue
+				var world_pos := _tile_to_world(x, y, z)
+				var xform := Transform3D(Basis(), world_pos)
+				multi_mesh.set_instance_transform(instance_idx, xform)
+				instance_idx += 1
+
+	var mesh_instance := MultiMeshInstance3D.new()
+	mesh_instance.multimesh = multi_mesh
+	mesh_instance.name = "tiles_%d" % tile_def.id
+	add_child(mesh_instance)
+	_mesh_instances[tile_def.id] = mesh_instance
+
+
+## Convert a tile grid coordinate to a world-space position (center of tile).
+func _tile_to_world(x: int, y: int, z: int) -> Vector3:
+	var origin := Vector3(
+		chunk_coord.x * tile_layer.width,
+		chunk_coord.y * tile_layer.height,
+		chunk_coord.z * tile_layer.depth
+	)
+	return origin + Vector3(
+		x * TILE_SIZE + TILE_SIZE * 0.5,
+		y * TILE_SIZE + TILE_SIZE * 0.5,
+		z * TILE_SIZE + TILE_SIZE * 0.5
+	)
+
+
+## Create a simple unit cube mesh for tile rendering.
+func _make_unit_cube_mesh() -> Mesh:
+	var mesh := BoxMesh.new()
+	mesh.size = Vector3(TILE_SIZE, TILE_SIZE, TILE_SIZE)
+	return mesh
+
+
+## Get the tile definition at a grid position, or null if empty.
+func get_tile_def_at(x: int, y: int, z: int = 0) -> TileDef:
+	if tile_layer == null:
+		return null
+	var tile_id := tile_layer.get_tile(x, y, z)
+	if tile_id == 0:
+		return null
+	return tile_layer.get_tile_def(tile_id)
+
+
+## Clear all rendered meshes.
+func clear() -> void:
+	for child in get_children():
+		child.queue_free()
+	_mesh_instances.clear()

scripts/tile_layer_node.gd.uid

@@ -0,0 +1 @@
+uid://d1x05tq8h43gm

scripts/world_object.gd

@@ -0,0 +1,135 @@
+class_name WorldObject
+extends RefCounted
+## A world object (static or dynamic) within a chunk.
+##
+## This is the runtime representation of a WorldObject from the chunk data
+## format (see docs/architecture/world.md §3.3). It holds the object's
+## identity, transform, properties, and moderation flags.
+
+## Stable object ID, unique within the chunk.
+var id: String = ""
+
+## Object type (e.g. "prop", "interactable", "spawn_point", "door").
+var type: String = ""
+
+## Reference to the object's mesh/glTF asset.
+var asset_id: String = ""
+
+## World-space position.
+var position: Vector3 = Vector3.ZERO
+
+## World-space rotation as a quaternion (x, y, z, w).
+var rotation: Vector4 = Vector4(0, 0, 0, 1)
+
+## World-space scale.
+var scale: Vector3 = Vector3.ONE
+
+## Type-specific key/value properties.
+var properties: Dictionary = {}
+
+## Whether this is a spawnable dynamic entity (true) or static (false).
+var is_dynamic: bool = false
+
+## Per-object content moderation flags.
+var flags: ChunkDataDecoder.ContentFlags = ChunkDataDecoder.ContentFlags.new()
+
+## Whether this object has been modified locally.
+var is_dirty: bool = false
+
+
+func _init(
+	p_id: String = "",
+	p_type: String = "",
+	p_asset_id: String = "",
+	p_position: Vector3 = Vector3.ZERO,
+	p_rotation: Vector4 = Vector4(0, 0, 0, 1),
+	p_scale: Vector3 = Vector3.ONE,
+	p_properties: Dictionary = {},
+	p_dynamic: bool = false,
+	p_flags: ChunkDataDecoder.ContentFlags = null
+) -> void:
+	id = p_id
+	type = p_type
+	asset_id = p_asset_id
+	position = p_position
+	rotation = p_rotation
+	scale = p_scale
+	properties = p_properties
+	is_dynamic = p_dynamic
+	if p_flags != null:
+		flags = p_flags
+
+
+## Get a property value by key.
+func get_property(key: String) -> Variant:
+	return properties.get(key)
+
+
+## Set a property value.
+func set_property(key: String, value: Variant) -> void:
+	properties[key] = value
+	is_dirty = true
+
+
+## Check if this object is walkable (based on properties).
+func is_walkable() -> bool:
+	return properties.get("walkable", true)
+
+
+## Check if this object is climbable (based on properties).
+func is_climbable() -> bool:
+	return properties.get("climbable", false)
+
+
+## Check if this object is interactable.
+func is_interactable() -> bool:
+	return type == "interactable" or properties.get("interactable", false)
+
+
+## Get the object's display name.
+func get_display_name() -> String:
+	return properties.get("display_name", id)
+
+
+## Serialize this object to a dictionary (for networking).
+func to_dict() -> Dictionary:
+	return {
+		"id": id,
+		"type": type,
+		"asset_id": asset_id,
+		"position": [position.x, position.y, position.z],
+		"rotation": [rotation.x, rotation.y, rotation.z, rotation.w],
+		"scale": [scale.x, scale.y, scale.z],
+		"properties": properties,
+		"dynamic": is_dynamic,
+	}
+
+
+## Create a WorldObject from a dictionary (for networking).
+static func from_dict(d: Dictionary) -> WorldObject:
+	var pos := Vector3(
+		d.get("position", [0, 0, 0])[0],
+		d.get("position", [0, 0, 0])[1],
+		d.get("position", [0, 0, 0])[2]
+	)
+	var rot := Vector4(
+		d.get("rotation", [0, 0, 0, 1])[0],
+		d.get("rotation", [0, 0, 0, 1])[1],
+		d.get("rotation", [0, 0, 0, 1])[2],
+		d.get("rotation", [0, 0, 0, 1])[3]
+	)
+	var scl := Vector3(
+		d.get("scale", [1, 1, 1])[0],
+		d.get("scale", [1, 1, 1])[1],
+		d.get("scale", [1, 1, 1])[2]
+	)
+	return WorldObject.new(
+		d.get("id", ""),
+		d.get("type", ""),
+		d.get("asset_id", ""),
+		pos,
+		rot,
+		scl,
+		d.get("properties", {}),
+		d.get("dynamic", false),
+	)

scripts/world_object.gd.uid

@@ -0,0 +1 @@
+uid://cxut2ghbsvobn