Server Integration (webrtc-server-library)

Server-side WebRTC signaling and room management. Manages Socket.IO connections and RTC sessions. Does not handle media; media is peer-to-peer or via SFU.

Overview

Responsibilities

• Socket.IO connection handling and event routing
• RTC session lifecycle (create, join, leave, end)
• Redis-backed session state for multi-instance scaling
• Optional: Cloudflare Workers SFU orchestration

The library creates a Socket.IO server, configures the Redis adapter for scaling, and registers handlers for all signaling events.

Redis: Required for session state and Socket.IO adapter. Stateless server: All session state is stored in Redis. Any instance can handle any connection.

Backend SDK structure (webrtc-server-library)

In the downloaded SDK package, the backend lives in webrtc-server-library/:

webrtc-server-library/
├── package.json   # main: "index.js"
├── index.js       # createWebRTCServer(opts), WebRTCServer
└── examples/
    └── index.js   # Minimal server: new WebRTCServer(), config, start()

Run npm install in this folder to install dependencies (e.g. socket.io, ioredis, express). Then require('webrtc-server-library') or point your app at this path. See the Public API section below for createWebRTCServer and WebRTCServer.

Public API

createWebRTCServer(opts)

Plugin-style setup. Does not create HTTP server or call listen. Attach to an existing HTTP server.

Option	Type	Required	Description
httpServer	http.Server	Yes	HTTP server for Socket.IO
redis	ioredis	Yes	Redis client
socketIO	Object	No	Socket.IO options
callbacks	Object	No	{ onEnd? }
cloudflare	Object	No	Cloudflare SFU config

Returns: { router, io, socketManager } — router has POST /rtc-session/leave-beacon; mount via app.use('/api', router).

Example: Plugin mode (Express)

const express = require('express');
const http = require('http');
const Redis = require('ioredis');
const { createWebRTCServer } = require('webrtc-server-library');

const app = express();
const httpServer = http.createServer(app);
const redis = new Redis({ host: 'localhost', port: 6379 });

const { router, io } = createWebRTCServer({
  httpServer,
  redis,
  callbacks: {
    onEnd: ({ rtc_session_id }) => console.log('Session ended:', rtc_session_id),
  },
});

app.use('/api', router);
httpServer.listen(3000);

Example: Standalone mode

const { WebRTCServer } = require('webrtc-server-library');

const server = new WebRTCServer();
server.config.port = 3000;
server.config.redis = { host: 'localhost', port: 6379 };

await server.start();
// Server listens on port 3000

WebRTCServer

Standalone server that creates app, HTTP server, and Redis.

Config: config.port (default 3000), config.redis, config.socketIO, config.cloudflare, config.callbacks.

Methods: start(), stop(), getIO(), getRedis(), getSocketManager().

Callbacks

onEnd({ rtc_session_id }) — Called after a session is ended (e.g. for licensing or metrics).

Examples

webrtc-server-library includes a minimal example server in examples/:

const WebRTCServer = require('webrtc-server-library');

const server = new WebRTCServer();
server.config.port = 3000;
server.config.redis = { host: 'localhost', port: 6379, db: 2 };
server.config.socketIO = {
  transports: ['websocket'],
  cors: { origin: '*', credentials: true },
};

server.start().then(() => console.log('Server on port 3000'));

Run: From webrtc-server-library root: npm run build then node examples/index.js. Requires Redis on localhost:6379 (db 2).

Pair with the client SDK examples (webrtc-library examples/vanilla/ or examples/react/) — point the client to http://localhost:3000.

Authentication

Rejects connections without id in handshake query. id is the user ID; name and image are optional. No token validation in the library; validate in Express middleware before Socket.IO upgrade, or in custom Socket.IO middleware.

Events & Lifecycle

Client connects with query: id, name?, image?, token?. Client emits rtc-session:join; response via rtc-session:join:response. Client emits rtc-session:leave to leave.

Deployment

Use HTTPS with a reverse proxy. Forward WebSocket upgrade headers. Default port 3000. Leave beacon: POST /api/rtc-session/leave-beacon with user_session_id.

Not Included

• TURN server — Provide your own; add TURN to client rtcConfig.iceServers
• Media transcoding — Media is peer-to-peer or SFU; no transcoding on this server
• Media recording — Not implemented
• Built-in auth — Validate tokens in your middleware