0b995ef75f1dee17b5e5ca17b12f5e4185439a15
Splits the WebSocket layer into three pieces so one app instance and many
behave identically: ConnectionManager stays a purely local socket registry;
RoomBroadcaster publishes chat messages to a per-room Redis channel and
every instance (including the publisher) forwards received messages to its
own local sockets via a single psubscribe("room:*") listener started in
main.py's lifespan; Presence is a Redis-backed refcounted hash per room
tracking who's connected across all instances.
Presence replaces the old process-local connected_user_ids check that
Phase 4's offline-push logic used -- without it, a user connected on a
different instance would look offline and get a redundant push. Fixing
this was scoped in beyond the issue's literal ask (message fan-out only)
since it's a real correctness gap in a phase specifically about running
more than one instance; a known limitation (no heartbeat/TTL, so a hard
crash leaks a presence increment) is documented in the README instead of
solved here.
New tests/test_broadcast.py spins up two independent app instances sharing
one Postgres + Redis to prove delivery and presence both actually cross
the Redis boundary, not just work in-process. Manually verified the same
thing against two real uvicorn processes on different ports.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
KeepItTalking
A web-based team chat service (Mattermost-style, no threaded conversations), invite-only. See ARCHITECTURE.md for the full system design and phased build plan.
Phase 1: auth, open-room CRUD, and single-instance WebSocket chat, backend
- a minimal frontend. Phase 2: private rooms, room roles (owner/admin/ member), and room invites — backend only, see below. Later phases (push notifications, Redis fan-out, the admin portal, the bot/extension system, and production deployment) are tracked as issues in the repo's issue tracker, prioritized.
Structure
backend/— FastAPI + SQLAlchemy 2.0 (async) + PostgreSQL. Seebackend/README.mdfor local setup, migrations, how to create a user (site registration is invite-only — no public sign-up endpoint), and the Phase 2 room-roles/invites API.frontend/— React + Vite PWA (login, room list, chat view). Still Phase-1-only: it doesn't yet call any of the Phase 2 endpoints. A UI redesign is happening separately; frontend work resumes once that lands.
Quickstart
# 1. Postgres (see backend/README.md for details)
docker run -d --name chatapp-postgres \
-e POSTGRES_USER=chatapp -e POSTGRES_PASSWORD=chatapp -e POSTGRES_DB=chatapp \
-p 5432:5432 postgres:16-alpine
# 2. Backend
cd backend
python3 -m venv .venv
.venv/bin/pip install -e ".[dev]"
cp .env.example .env # then set SESSION_SECRET
.venv/bin/alembic upgrade head
.venv/bin/python -m app.cli create-user alice alice@example.com "some-password"
.venv/bin/uvicorn app.main:app --reload &
# 3. Frontend (in another shell)
cd frontend
npm install
npm run dev
Then open http://localhost:5173 and log in with the account created above.
The Vite dev server proxies /api and /ws to the backend on :8000, so no
CORS configuration is needed in development.
Deployment
Not part of Phase 1. The target is two plain Linux servers with no containers — see ARCHITECTURE.md §9 and the corresponding "Production deployment" issue in the tracker.