videochat

A WebRTC application built with a Go signaling server and a SolidJS single-page app. Uses Redis to track connected peers and who is currently broadcasting.

Stack

• Go HTTP/WebSocket server (Gorilla WebSocket)
• Redis for lightweight presence state
• SolidJS + Vite frontend
• Optional TURN relay (coturn) for fallback when STUN/host fails

Prerequisites

• Go 1.21+ (tested with recent Go releases)
• Bun for the frontend build
• Redis running and reachable (defaults to localhost:6379)

Quick Start

# 1) Install frontend deps
cd frontend
npm install          # or bun install

# 2) Build the frontend assets
npm run build        # emits dist/ consumed by the Go server

# 3) Run Redis (if not already running)
redis-server &

# 4) Start the Go backend (serves the built frontend and /ws)
cd ../backend
go run main.go

Then open http://localhost:8080 in multiple tabs to see peers join and start/stop broadcasting.

Rooms

• Rooms are private and created on demand. Use the landing page “Create private room” button or POST /api/rooms to get a {code, url}.
• Share the room URL (e.g., /rooms/{code}) so peers can join and enter a display name.
• WebSocket connections must include the room code (/ws?room={code}); presence and broadcasts are isolated per room using Redis.

Configuration

Environment variables (optional):

• ADDR - HTTP listen address (default :8080)
• REDIS_ADDR - Redis address (default localhost:6379)
• STATIC_DIR - Path to the frontend dist/ (default ../frontend/dist)
• WS_PUBLIC_URL - Optional; explicit WebSocket URL to advertise to clients (defaults to request host/proto and /ws)
• STUN_URLS - Comma-separated STUN URLs (default stun:stun.l.google.com:19302)
• TURN_URLS - Comma-separated TURN URLs (e.g., turn:TURN_HOST:3478?transport=udp,turn:TURN_HOST:3478?transport=tcp)
• TURN_USERNAME / TURN_PASSWORD - Credentials for TURN servers (if required)
• ICE_MODE - Optional; stun-turn (default) keeps both STUN+TURN, turn-only drops STUN and forces relay, stun-only skips TURN.

.env files are loaded from the project root, backend/.env, or ../.env. Copy .env.example to .env and adjust TURN host/credentials to match your coturn config. Debug ICE config at runtime with curl http://localhost:8080/debug/ice (shows servers and mode). Client settings (WebSocket URL, ICE mode/servers) are available at GET /api/settings; the WS URL defaults to the incoming request host unless WS_PUBLIC_URL is set.

Development

• Frontend: npm run dev -- --host from frontend/ for hot reload; the app reads the signaling URL from /api/settings (set WS_PUBLIC_URL on the backend if the public host differs).
• Backend: go run main.go from backend/. The server resets Redis presence sets on startup to avoid stale peer lists after restarts.

TURN (coturn)

• Coturn config lives in coturn/. Copy coturn/turnserver.conf.example to coturn/turnserver.conf and adjust realm, external-ip, ports, and credentials.
• Start coturn:
  • Native: turnserver -c coturn/turnserver.conf (stop via service manager or pkill turnserver).
  • Docker: cd coturn && ./run-docker.sh (stop with ./stop-docker.sh, container name defaults to webrtc-coturn).
• Ensure TURN creds match TURN_USERNAME / TURN_PASSWORD envs. When TURN is configured, the backend passes both STUN and TURN entries to the frontend via the WebSocket welcome message; ICE will try host/STUN first and fall back to TURN.
• Deployment runbook and pricing analysis live in docs/TURN_DEPLOYMENT_GUIDE.md and docs/TURN_HOSTING_PRICE_ANALYSIS.md.