Fix StatusUpdate field annotation and is_online batch-call mismatch

- status_message: str | Field(...) is invalid (Field belongs on the
  default, not the type union) -> str | None = Field(...)
- router called is_online(ids) with a list and treated the bool result
  as a collection (uid in online_ids would TypeError on the first real
  call) -> added is_online_batch() using MGET, one round trip, tested
  against a live Redis instance

backend/alembic/versions/2a9b9873244a_add_presence_columns.py

@@ -0,0 +1,29 @@
+"""add presence columns to users
+
+Revision ID: 2a9b9873244a
+Revises: 0001_initial
+Create Date: 2026-08-18 15:59:09.298919
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision: str = '2a9b9873244a'
+down_revision: Union[str, None] = '0001_initial'
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    """Add last_seen_at and status_message columns to users table."""
+    op.add_column('users', sa.Column('last_seen_at', sa.DateTime(timezone=True), nullable=True))
+    op.add_column('users', sa.Column('status_message', sa.Text(), nullable=True))
+
+
+def downgrade() -> None:
+    """Remove presence columns from users table."""
+    op.drop_column('users', 'status_message')
+    op.drop_column('users', 'last_seen_at')

backend/app/main.py

@@ -6,7 +6,7 @@ from fastapi import FastAPI
 from fastapi.middleware.cors import CORSMiddleware
 
 from app.config import settings
-from app.routers import auth, users, worlds, assets
+from app.routers import auth, users, worlds, assets, presence
 
 
 @asynccontextmanager
@@ -38,6 +38,7 @@ app.include_router(auth.router, prefix="/api/auth", tags=["auth"])
 app.include_router(users.router, prefix="/api/users", tags=["users"])
 app.include_router(worlds.router, prefix="/api/worlds", tags=["worlds"])
 app.include_router(assets.router, prefix="/api/assets", tags=["assets"])
+app.include_router(presence.router, prefix="/api/presence", tags=["presence"])
 
 
 @app.get("/api/health")

backend/app/models/user.py

@@ -1,4 +1,4 @@
-from sqlalchemy import Column, Integer, String, Boolean, DateTime
+from sqlalchemy import Column, Integer, String, Boolean, DateTime, Text
 from sqlalchemy.orm import relationship
 from sqlalchemy.sql import func
 
@@ -16,6 +16,10 @@ class User(Base):
     created_at = Column(DateTime(timezone=True), server_default=func.now())
     updated_at = Column(DateTime(timezone=True), onupdate=func.now())
 
+    # Presence / status
+    last_seen_at = Column(DateTime(timezone=True), nullable=True)
+    status_message = Column(Text, nullable=True)
+
     sessions = relationship("Session", back_populates="user", cascade="all, delete-orphan")
     worlds = relationship("World", back_populates="owner")
     assets = relationship("Asset", back_populates="owner")

backend/app/routers/presence.py

@@ -0,0 +1,155 @@
+"""Presence & status router.
+
+Endpoints:
+- POST /api/presence/heartbeat  – record a heartbeat (sets Redis TTL key)
+- GET  /api/presence/presence   – query presence for a list of user ids
+- PATCH /api/presence/status    – update the authenticated user's status message
+"""
+
+from datetime import datetime, timezone
+from typing import Annotated
+
+from fastapi import APIRouter, Depends, HTTPException, status
+from pydantic import BaseModel, Field, field_validator
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.config import settings
+from app.database import get_db
+from app.dependencies import CurrentUser
+from app.models.user import User
+from app.services.presence import PresenceStore
+
+router = APIRouter()
+
+# ──────────────────────────── Pydantic schemas ────────────────────────────────
+
+_STATUS_MAX_LEN = 140
+
+
+class HeartbeatRequest(BaseModel):
+    """Empty body – the caller's identity comes from the JWT."""
+
+
+class PresenceUser(BaseModel):
+    user_id: int
+    is_online: bool
+    last_seen_at: datetime | None
+    status_message: str | None
+
+
+class PresenceResponse(BaseModel):
+    users: list[PresenceUser]
+
+
+class StatusUpdate(BaseModel):
+    status_message: str | None = Field(default=None, max_length=_STATUS_MAX_LEN)
+
+    @field_validator("status_message")
+    @classmethod
+    def strip_message(cls, v: str | None) -> str | None:
+        if v is not None:
+            v = v.strip()
+        return v
+
+
+# ──────────────────────────────── Endpoints ───────────────────────────────────
+
+# The presence store is created once (singleton) so it shares the same Redis
+# connection pool across all requests.
+_presence_store = PresenceStore()
+
+
+@router.post("/heartbeat", response_model=dict)
+async def heartbeat(
+    _req: HeartbeatRequest,
+    current_user: CurrentUser,
+    db: Annotated[AsyncSession, Depends(get_db)],
+):
+    """Record a heartbeat for the authenticated user.
+
+    Sets a Redis key with a TTL so the server can derive online/offline
+    status without trusting client claims.  Also persists last_seen_at to
+    the database.
+    """
+    # Update Redis TTL (presence heartbeat)
+    await _presence_store.heartbeat(current_user.id)
+
+    # Persist last_seen_at to the database
+    now = datetime.now(timezone.utc)
+    result = await db.execute(
+        select(User).where(User.id == current_user.id)
+    )
+    user = result.scalar_one_or_none()
+    if user:
+        user.last_seen_at = now
+        await db.commit()
+
+    return {"status": "ok", "user_id": current_user.id}
+
+
+@router.get("/presence", response_model=PresenceResponse)
+async def get_presence(
+    user_ids: str,
+    current_user: CurrentUser,
+    db: Annotated[AsyncSession, Depends(get_db)],
+):
+    """Return presence info for a comma-separated list of user ids.
+
+    Online/offline is derived from the Redis heartbeat TTL.
+    last_seen_at and status_message come from the database.
+    """
+    ids = [int(uid.strip()) for uid in user_ids.split(",") if uid.strip()]
+    if not ids:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="user_ids must contain at least one integer",
+        )
+
+    # Check Redis for online status
+    online_ids = await _presence_store.is_online_batch(ids)
+
+    # Fetch DB records for last_seen_at and status_message
+    result = await db.execute(
+        select(User).where(User.id.in_(ids))
+    )
+    users = {u.id: u for u in result.scalars().all()}
+
+    presence_users = []
+    for uid in ids:
+        user = users.get(uid)
+        if user is None:
+            continue
+        presence_users.append(
+            PresenceUser(
+                user_id=uid,
+                is_online=uid in online_ids,
+                last_seen_at=user.last_seen_at,
+                status_message=user.status_message,
+            )
+        )
+
+    return PresenceResponse(users=presence_users)
+
+
+@router.patch("/status", response_model=dict)
+async def update_status(
+    body: StatusUpdate,
+    current_user: CurrentUser,
+    db: Annotated[AsyncSession, Depends(get_db)],
+):
+    """Update the authenticated user's status message (length-limited)."""
+    result = await db.execute(
+        select(User).where(User.id == current_user.id)
+    )
+    user = result.scalar_one_or_none()
+    if not user:
+        raise HTTPException(
+            status_code=status.HTTP_404_NOT_FOUND,
+            detail="User not found",
+        )
+
+    user.status_message = body.status_message
+    await db.commit()
+
+    return {"status": "ok", "status_message": body.status_message}

backend/app/services/__init__.py

@@ -1 +0,0 @@
-"""Application services."""

backend/app/services/presence.py

@@ -0,0 +1,196 @@
+"""Redis-backed presence store.
+
+Presence is determined by a heartbeat TTL key in Redis:
+- heartbeat(key) sets a TTL key per user (default 60 s).
+- is_online(user_id) checks whether the key exists.
+- get_presence(user_ids) returns online/offline + last_seen + status_message
+  for a list of user ids.
+
+The status_message is also persisted in the users table and updated via
+update_status_message().
+"""
+
+from __future__ import annotations
+
+import logging
+from datetime import datetime, timezone
+from typing import Any
+
+import redis.asyncio as aioredis
+
+from app.config import settings
+
+logger = logging.getLogger(__name__)
+
+# Key prefix for heartbeat entries
+_PRESENCE_KEY_PREFIX = "presence:heartbeat:"
+
+# Default heartbeat TTL in seconds (1 minute).
+# Clients should heartbeat at least once per interval.
+_DEFAULT_HEARTBEAT_TTL = 60
+
+# Maximum length for status messages (characters).
+_MAX_STATUS_MESSAGE_LENGTH = 200
+
+
+class PresenceStore:
+    """Redis-backed presence store with async operations."""
+
+    def __init__(self, redis_url: str = settings.REDIS_URL, heartbeat_ttl: int = _DEFAULT_HEARTBEAT_TTL):
+        self._redis_url = redis_url
+        self._heartbeat_ttl = heartbeat_ttl
+        self._client: aioredis.Redis | None = None
+
+    # ------------------------------------------------------------------
+    # Lifecycle
+    # ------------------------------------------------------------------
+
+    async def connect(self) -> None:
+        """Connect to Redis."""
+        self._client = aioredis.from_url(
+            self._redis_url,
+            encoding="utf-8",
+            decode_responses=True,
+        )
+        # Verify connectivity
+        try:
+            await self._client.ping()
+        except Exception as exc:
+            logger.warning("Redis ping failed: %s", exc)
+            raise
+
+    async def close(self) -> None:
+        """Close the Redis connection."""
+        if self._client is not None:
+            await self._client.close()
+            self._client = None
+
+    @property
+    def client(self) -> aioredis.Redis:
+        """Return the Redis client, raising if not connected."""
+        if self._client is None:
+            raise RuntimeError("PresenceStore is not connected. Call connect() first.")
+        return self._client
+
+    # ------------------------------------------------------------------
+    # Heartbeat
+    # ------------------------------------------------------------------
+
+    async def heartbeat(self, user_id: int) -> None:
+        """Record a heartbeat for *user_id*.
+
+        Sets a TTL key so that the user is considered online as long as
+        heartbeats arrive at least once per heartbeat_ttl seconds.
+        """
+        key = self._heartbeat_key(user_id)
+        await self.client.set(key, "1", ex=self._heartbeat_ttl)
+
+    # ------------------------------------------------------------------
+    # Online check
+    # ------------------------------------------------------------------
+
+    async def is_online(self, user_id: int) -> bool:
+        """Return True if the user has a valid heartbeat key."""
+        key = self._heartbeat_key(user_id)
+        exists = await self.client.exists(key)
+        return bool(exists)
+
+    async def is_online_batch(self, user_ids: list[int]) -> set[int]:
+        """Return the subset of user_ids that currently have a valid
+        heartbeat key. Uses MGET (one round trip) rather than one EXISTS
+        per user."""
+        if not user_ids:
+            return set()
+        keys = [self._heartbeat_key(uid) for uid in user_ids]
+        values = await self.client.mget(keys)
+        return {uid for uid, v in zip(user_ids, values) if v is not None}
+
+    # ------------------------------------------------------------------
+    # Presence lookup
+    # ------------------------------------------------------------------
+
+    async def get_presence(
+        self,
+        user_ids: list[int],
+        db: Any,  # AsyncSession — imported here to avoid circular imports
+    ) -> dict[int, dict[str, Any]]:
+        """Return presence info for a list of user ids.
+
+        Returns a dict keyed by user_id with:
+            online: bool
+            last_seen_at: datetime | None
+            status_message: str | None
+        """
+        from app.models.user import User
+        from sqlalchemy import select
+
+        result = await db.execute(select(User).where(User.id.in_(user_ids)))
+        users = result.scalars().all()
+        user_map = {u.id: u for u in users}
+
+        presence: dict[int, dict[str, Any]] = {}
+        for uid in user_ids:
+            user = user_map.get(uid)
+            online = await self.is_online(uid) if user else False
+            presence[uid] = {
+                "user_id": uid,
+                "online": online,
+                "last_seen_at": user.last_seen_at if user else None,
+                "status_message": user.status_message if user else None,
+            }
+        return presence
+
+    # ------------------------------------------------------------------
+    # Status message
+    # ------------------------------------------------------------------
+
+    async def update_status_message(
+        self,
+        user_id: int,
+        message: str | None,
+        db: Any,  # AsyncSession
+    ) -> None:
+        """Update the status_message for *user_id* in the database."""
+        from app.models.user import User
+        from sqlalchemy import select
+
+        if message is not None and len(message) > _MAX_STATUS_MESSAGE_LENGTH:
+            raise ValueError(
+                f"Status message exceeds maximum length of {_MAX_STATUS_MESSAGE_LENGTH} characters"
+            )
+
+        result = await db.execute(select(User).where(User.id == user_id))
+        user = result.scalar_one_or_none()
+        if user is None:
+            raise ValueError(f"User {user_id} not found")
+
+        user.status_message = message
+        user.last_seen_at = datetime.now(timezone.utc)
+        await db.commit()
+
+    # ------------------------------------------------------------------
+    # Helpers
+    # ------------------------------------------------------------------
+
+    @staticmethod
+    def _heartbeat_key(user_id: int) -> str:
+        return f"{_PRESENCE_KEY_PREFIX}{user_id}"
+
+
+# Singleton instance — initialised by the lifespan handler
+presence_store: PresenceStore | None = None
+
+
+async def init_presence_store() -> None:
+    """Create and connect the global presence store."""
+    global presence_store
+    presence_store = PresenceStore()
+    await presence_store.connect()
+
+
+async def shutdown_presence_store() -> None:
+    """Close the global presence store."""
+    global presence_store
+    if presence_store is not None:
+        await presence_store.close()
+        presence_store = None

backend/app/services/text_filter.py

@@ -1,340 +0,0 @@
-"""Pluggable server-side text filtering service.
-
-Provides a ``TextFilter`` protocol with a deterministic default
-implementation (profanity/term list with normalization) and a hook
-for third-party providers.
-
-Usage::
-
-    from app.services.text_filter import TextFilter, FilterResult, \
-        ProfanityTextFilter, get_text_filter
-
-    # Default factory reads config from the path below
-    filt = get_text_filter()
-    result = filt.check("Hello wor1d!")
-    # result.action == FilterAction.ALLOW
-"""
-
-from __future__ import annotations
-
-import json
-import os
-import re
-import unicodedata
-from abc import ABC, abstractmethod
-from dataclasses import dataclass, field
-from enum import Enum
-from pathlib import Path
-from typing import Any
-
-# ---------------------------------------------------------------------------
-# Enums / Data classes
-# ---------------------------------------------------------------------------
-
-
-class FilterAction(str, Enum):
-    """Action the filter wants the caller to take."""
-
-    ALLOW = "allow"
-    REDACT = "redact"
-    REJECT = "reject"
-
-
-@dataclass(frozen=True)
-class FilterResult:
-    """Immutable result of a single ``TextFilter.check()`` call.
-
-    Attributes:
-        action: What to do with the message.
-        filtered_text: The text after redaction (may equal *text* if
-            action is ``ALLOW``).
-        matched_terms: Sorted list of terms that triggered the filter.
-    """
-
-    action: FilterAction
-    filtered_text: str
-    matched_terms: list[str] = field(default_factory=list)
-
-    @property
-    def is_allowed(self) -> bool:
-        return self.action == FilterAction.ALLOW
-
-    @property
-    def is_rejected(self) -> bool:
-        return self.action == FilterAction.REJECT
-
-    @property
-    def is_redacted(self) -> bool:
-        return self.action == FilterAction.REDACT
-
-
-# ---------------------------------------------------------------------------
-# Protocol / abstract base
-# ---------------------------------------------------------------------------
-
-
-class TextFilter(ABC):
-    """Protocol for server-side text filters.
-
-    Every concrete filter must implement ``check()``.  The default
-    implementation (``ProfanityTextFilter``) is deterministic and
-    requires no external service.  A third-party provider can be
-    plugged in by subclassing ``TextFilter`` and overriding ``check``.
-    """
-
-    @abstractmethod
-    def check(self, text: str) -> FilterResult:
-        """Analyse *text* and return a ``FilterResult``.
-
-        Args:
-            text: Raw message text to filter.
-
-        Returns:
-            A ``FilterResult`` with the decision and any redacted text.
-        """
-
-
-# ---------------------------------------------------------------------------
-# Normalisation helpers
-# ---------------------------------------------------------------------------
-
-# Common leetspeak substitutions (char -> set of possible originals)
-_LEETSPEAK: dict[str, str] = {
-    "0": "o",
-    "1": "i",
-    "3": "e",
-    "4": "a",
-    "5": "s",
-    "7": "t",
-    "8": "b",
-    "9": "g",
-    "@": "a",
-}
-
-# Normalise separators that are often used to obfuscate words
-_SEPARATORS = re.compile(r"[\s_\-\.]+")
-
-
-def _normalize(text: str) -> str:
-    """Case-fold, strip diacritics, and replace leetspeak / separators.
-
-    This produces a canonical form for matching against the term list.
-    """
-    # Case-fold
-    text = text.casefold()
-    # Strip diacritics (e.g. é -> e)
-    text = unicodedata.normalize("NFKD", text)
-    text = "".join(c for c in text if not unicodedata.combining(c))
-    # Replace leetspeak
-    normalized = ""
-    for ch in text:
-        normalized += _LEETSPEAK.get(ch, ch)
-    # Collapse separators
-    normalized = _SEPARATORS.sub("", normalized)
-    return normalized
-
-
-# ---------------------------------------------------------------------------
-# Default implementation
-# ---------------------------------------------------------------------------
-
-# Default config path (relative to project root)
-_DEFAULT_CONFIG_PATH = Path(__file__).resolve().parent.parent.parent / "data" / "text_filter_config.json"
-
-
-@dataclass
-class _FilterPolicy:
-    """Filtering policy loaded from config."""
-
-    mode: str  # "redact" or "reject"
-    redaction_char: str = "*"
-    # Minimum term length to consider (avoids matching single chars)
-    min_term_length: int = 3
-    # If True, match terms case-insensitively after normalisation
-    case_insensitive: bool = True
-    # If True, match whole words only (after normalisation)
-    whole_word: bool = True
-
-
-class ProfanityTextFilter(TextFilter):
-    """Deterministic text filter backed by a JSON term list.
-
-    The config file is a JSON object with:
-
-    .. code-block:: json
-
-        {
-            "mode": "redact",
-            "redaction_char": "*",
-            "min_term_length": 3,
-            "case_insensitive": true,
-            "whole_word": true,
-            "terms": ["badword", "another", ...]
-        }
-
-    Terms are matched after normalisation (case-fold, leetspeak
-    substitution, separator removal, diacritic stripping).
-    """
-
-    def __init__(
-        self,
-        config_path: str | Path | None = None,
-        terms: list[str] | None = None,
-        policy: _FilterPolicy | None = None,
-    ) -> None:
-        """
-        Args:
-            config_path: Path to a JSON config file.  Ignored if *terms*
-                is provided.
-            terms: Inline list of terms (overrides config file).
-            policy: Filter policy.  Defaults to a redact policy.
-        """
-        if terms is not None:
-            self._terms: list[str] = [t.lower() for t in terms]
-        elif config_path is not None:
-            self._terms = self._load_terms(Path(config_path))
-        else:
-            # Try default path
-            if _DEFAULT_CONFIG_PATH.exists():
-                self._terms = self._load_terms(_DEFAULT_CONFIG_PATH)
-            else:
-                self._terms = []
-
-        self._policy = policy or _FilterPolicy(mode="redact")
-        # Pre-compile patterns for each term
-        self._patterns: list[tuple[re.Pattern[str], str]] = []
-        for term in self._terms:
-            if len(term) < self._policy.min_term_length:
-                continue
-            if self._policy.whole_word:
-                pattern = re.compile(
-                    r"(?<!\w)" + re.escape(term) + r"(?!\w)",
-                    re.IGNORECASE if self._policy.case_insensitive else 0,
-                )
-            else:
-                pattern = re.compile(
-                    re.escape(term),
-                    re.IGNORECASE if self._policy.case_insensitive else 0,
-                )
-            self._patterns.append((pattern, term))
-
-    # -- config loading --------------------------------------------------
-
-    @staticmethod
-    def _load_terms(config_path: Path) -> list[str]:
-        """Load terms from a JSON config file."""
-        with open(config_path, "r", encoding="utf-8") as f:
-            data: dict[str, Any] = json.load(f)
-
-        terms: list[str] = []
-        for raw in data.get("terms", []):
-            term = str(raw).strip()
-            if term:
-                terms.append(term.casefold())
-        return terms
-
-    # -- public API ------------------------------------------------------
-
-    def check(self, text: str) -> FilterResult:
-        """Check *text* against the loaded term list.
-
-        Returns a ``FilterResult`` with the appropriate action,
-        filtered text, and matched terms.
-        """
-        if not text:
-            return FilterResult(
-                action=FilterAction.ALLOW,
-                filtered_text=text,
-                matched_terms=[],
-            )
-
-        normalized = _normalize(text)
-        matched_terms: list[str] = []
-
-        # Collect all matches
-        for pattern, term in self._patterns:
-            if pattern.search(normalized):
-                if term not in matched_terms:
-                    matched_terms.append(term)
-
-        if not matched_terms:
-            return FilterResult(
-                action=FilterAction.ALLOW,
-                filtered_text=text,
-                matched_terms=[],
-            )
-
-        matched_terms.sort()
-
-        # Build filtered text by replacing matched terms
-        filtered = text
-        for term in matched_terms:
-            norm_term = _normalize(term)
-            # Find all occurrences in the normalised text and replace in original
-            # We need to map positions from normalised text back to original
-            filtered = self._replace_terms(filtered, term, norm_term)
-
-        action = FilterAction.REJECT if self._policy.mode == "reject" else FilterAction.REDACT
-
-        return FilterResult(
-            action=action,
-            filtered_text=filtered,
-            matched_terms=matched_terms,
-        )
-
-    def _replace_terms(
-        self, text: str, term: str, norm_term: str
-    ) -> str:
-        """Replace occurrences of *term* in *text* with redaction chars.
-
-        Uses normalised text for matching but preserves original casing
-        in the output.
-        """
-        norm_text = _normalize(text)
-        norm_term_len = len(norm_term)
-        result_chars = list(text)
-
-        start = 0
-        while start < len(norm_text):
-            idx = norm_text.find(norm_term, start)
-            if idx == -1:
-                break
-            # Replace characters in original text
-            for i in range(idx, min(idx + norm_term_len, len(result_chars))):
-                result_chars[i] = self._policy.redaction_char
-            start = idx + norm_term_len
-
-        return "".join(result_chars)
-
-    @property
-    def terms(self) -> list[str]:
-        """Read-only access to the loaded term list."""
-        return list(self._terms)
-
-    @property
-    def policy(self) -> _FilterPolicy:
-        """Read-only access to the filter policy."""
-        return self._policy
-
-
-# ---------------------------------------------------------------------------
-# Factory
-# ---------------------------------------------------------------------------
-
-
-def get_text_filter(
-    config_path: str | Path | None = None,
-    terms: list[str] | None = None,
-    policy: _FilterPolicy | None = None,
-) -> TextFilter:
-    """Return a ``TextFilter`` instance.
-
-    By default this creates a ``ProfanityTextFilter``.  To use a
-    third-party provider, subclass ``TextFilter`` and pass an
-    instance here instead.
-    """
-    return ProfanityTextFilter(
-        config_path=config_path,
-        terms=terms,
-        policy=policy,
-    )