socketio

# Socket.io Skill Expert assistance for building real-time applications with Socket.io. ## Capabilities - Configure Socket.io server - Implement rooms and namespaces - Use Redis adapter for scaling - Handle authentication middleware - Build event-driven patterns - Implement acknowledgements ## Usage Invoke this skill when you need to: - Build real-time applications - Implement chat rooms - Scale WebSocket servers - Handle complex event patterns ## Server Setup ```typescript import { Server } from 'socket.io'; import { createAdapter } from '@socket.io/redis-adapter'; import { createClient } from 'redis'; const io = new Server(httpServer, { cors: { origin: '*' }, }); // Redis adapter for scaling const pubClient = createClient({ url: process.env.REDIS_URL }); const subClient = pubClient.duplicate(); io.adapter(createAdapter(pubClient, subClient)); // Authentication middleware io.use((socket, next) => { const token = socket.handshake.auth.token; try { socket.user = verifyToken(token); next(); } catch { next(new Error('Authentication failed')); } }); // Namespaces const chatNamespace = io.of('/chat'); chatNamespace.on('connection', (socket) => { socket.on('join-room', (roomId) => { socket.join(roomId); socket.to(roomId).emit('user-joined', socket.user); }); socket.on('message', ({ roomId, content }) => { io.to(roomId).emit('message', { user: socket.user, content, timestamp: Date.now(), }); }); }); ``` ##...