socket-io

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Documentation

SKILL.md

Socket.IO real-time bidirectional communication. Rooms, namespaces, acknowledgments, middleware, scaling with Redis adapter, and TypeScript types.

npx skills add claude-dev-suite/claude-dev-suite --skill socket-io

Documentation

SKILL.mdView source

Socket.IO

Server Setup

import { Server } from 'socket.io';

Client Setup

Scaling with Redis Adapter

React Hook

Anti-Patterns

Anti-Pattern	Fix
No authentication	Use `io.use()` middleware with JWT
Broadcasting to all instead of rooms	Use `socket.to(room).emit()`
No reconnection handling	Enable reconnection, show UI indicator
Single server without adapter	Use Redis adapter for horizontal scaling
No acknowledgments for critical events	Use callback parameter for delivery confirmation

Production Checklist

Authentication middleware on connection
Redis adapter for multi-server deployment
Reconnection with exponential backoff
Room-based message scoping
Connection state UI indicator
Rate limiting on message events

npx skills add claude-dev-suite/claude-dev-suite --skill socket-io

Documentation

SKILL.md

socket-io skill by claude-dev-suite | SkillBundle

import { io, Socket } from 'socket.io-client';
 
const socket: Socket<ServerToClientEvents, ClientToServerEvents> = io(API_URL, {
  auth: { token: getAuthToken() },
  reconnection: true,
  reconnectionDelay: 1000,
});
 
socket.on('connect', () => console.log('Connected'));
socket.on('message', (data) => addMessage(data));
socket.on('connect_error', (err) => console.error(err.message));
 
// With acknowledgment
socket.emit('sendMessage', 'Hello!', (status) => {
  if (status === 'error') showError('Failed to send');
});

import { createAdapter } from '@socket.io/redis-adapter';
import { createClient } from 'redis';
 
const pubClient = createClient({ url: process.env.REDIS_URL });
const subClient = pubClient.duplicate();
await Promise.all([pubClient.connect(), subClient.connect()]);
 
io.adapter(createAdapter(pubClient, subClient));

function useSocket(room: string) {
  const [messages, setMessages] = useState<Message[]>([]);
 
  useEffect(() => {
    socket.emit('joinRoom', room);
    socket.on('message', (msg) => setMessages((prev) => [...prev, msg]));
    return () => { socket.off('message'); };
  }, [room]);
 
  const send = (text: string) => socket.emit('sendMessage', text, () => {});
  return { messages, send };
}