socket-io

Included with Lifetime

$97 forever

Socket.IO real-time bidirectional communication. Rooms, namespaces, acknowledgments, middleware, scaling with Redis adapter, and TypeScript types. USE WHEN: user mentions "Socket.IO", "socket.io", "real-time chat", "live updates", "bidirectional WebSocket", "rooms", "namespaces" DO NOT USE FOR: SSE (server-sent events) - use `sse`; WebRTC - use `webrtc`; raw WebSocket without Socket.IO - use framework WS skills

Backend & APIs

What this skill does

# Socket.IO

## Server Setup

```typescript
import { Server } from 'socket.io';
import { createServer } from 'http';

const httpServer = createServer(app);

interface ServerToClientEvents {
  message: (data: { user: string; text: string; timestamp: number }) => void;
  userJoined: (user: string) => void;
}

interface ClientToServerEvents {
  sendMessage: (text: string, callback: (status: 'ok' | 'error') => void) => void;
  joinRoom: (room: string) => void;
}

const io = new Server<ClientToServerEvents, ServerToClientEvents>(httpServer, {
  cors: { origin: process.env.CLIENT_URL },
});

// Authentication middleware
io.use((socket, next) => {
  const token = socket.handshake.auth.token;
  try {
    socket.data.user = verifyToken(token);
    next();
  } catch {
    next(new Error('Authentication failed'));
  }
});

io.on('connection', (socket) => {
  console.log(`${socket.data.user.name} connected`);

  socket.on('joinRoom', (room) => {
    socket.join(room);
    socket.to(room).emit('userJoined', socket.data.user.name);
  });

  socket.on('sendMessage', (text, callback) => {
    const message = { user: socket.data.user.name, text, timestamp: Date.now() };
    io.to('general').emit('message', message);
    callback('ok');
  });

  socket.on('disconnect', () => {
    console.log(`${socket.data.user.name} disconnected`);
  });
});
```

## Client Setup

```typescript
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');
});
```

## Scaling with Redis Adapter

```typescript
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));
```

## React Hook

```tsx
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 };
}
```

## 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

Files: 1

Size: 3.8 KB

Complexity: 15/100

Category: Backend & APIs

Source: https://github.com/claude-dev-suite/claude-dev-suite/tree/main/skills/real-time/socket-io

Related in Backend & APIs

jfrog

Included

Interact with the JFrog Platform via the JFrog CLI and REST/GraphQL APIs. Use this skill when the user wants to manage Artifactory repositories, upload or download artifacts, manage builds, configure permissions, manage users and groups, work with access tokens, configure JFrog CLI servers, search artifacts, manage properties, set up replication, manage JFrog Projects, run security audits or scans, look up CVE details, query exposures scan results from JFrog Advanced Security, manage release bundles and lifecycle operations, aggregate or export platform data, or perform any JFrog Platform administration task. Also use when the user mentions jf, jfrog, artifactory, xray, distribution, evidence, apptrust, onemodel, graphql, workers, mission control, curation, advanced security, exposures, or any JFrog product name.

Backend & APIsscripts

cupynumeric-migration-readiness

Included

Pre-migration readiness assessor for porting NumPy to cuPyNumeric. Use BEFORE substantial porting work begins when the user asks whether code will scale on GPU, whether they should migrate to cuPyNumeric, which NumPy patterns transfer cleanly, what must be refactored before porting, or mentions pre-port assessment, scaling analysis, or refactor planning. Inspect the user's source code, look up NumPy usage, cross-reference the cuPyNumeric API support manifest, and distinguish distributed-scaling-friendly patterns from blockers such as unsupported APIs, scalar synchronization, host round-trips, Python/object-heavy control flow, shape/data-dependent branching, and in-place mutation hazards. Produce a verdict of READY, LIGHT REFACTOR, SIGNIFICANT REFACTOR, or NOT RECOMMENDED, with concrete refactor pointers.

Backend & APIsscripts

alibabacloud-data-agent-skill

Included

Invoke Alibaba Cloud Apsara Data Agent for Analytics via CLI to perform natural language-driven data analysis on enterprise databases. Data Agent for Analytics is an intelligent data analysis agent developed by Alibaba Cloud Database team for enterprise users. It automatically completes requirement analysis, data understanding, analysis insights, and report generation based on natural language descriptions. This tool supports: discovering data resources (instances/databases/tables) managed in DMS, initiating query or deep analysis sessions, real-time progress tracking, and retrieving analysis conclusions and generated reports. Use this Skill when users need to query databases, analyze data trends, generate data reports, ask questions in natural language, or mention "Data Agent", "data analysis", "database query", "SQL analysis", "data insights".

Backend & APIsscripts

token-optimizer

Included

Reduce OpenClaw token usage and API costs through smart model routing, heartbeat optimization, budget tracking, and native 2026.2.15 features (session pruning, bootstrap size limits, cache TTL alignment). Use when token costs are high, API rate limits are being hit, or hosting multiple agents at scale. The 4 executable scripts (context_optimizer, model_router, heartbeat_optimizer, token_tracker) are local-only — no network requests, no subprocess calls, no system modifications. Reference files (PROVIDERS.md, config-patches.json) document optional multi-provider strategies that require external API keys and network access if you choose to use them. See SECURITY.md for full breakdown.

Backend & APIsscripts

resend-cli

Included

Use this skill when the task is specifically about operating Resend from an AI agent, terminal session, or CI job via the official resend CLI: installing/authenticating the CLI, sending/listing/updating/cancelling emails, batch sends, domains and DNS, webhooks and local listeners, inbound receiving, contacts, topics, segments, broadcasts, templates, API keys, profiles, or debugging Resend CLI/API failures. Trigger on mentions of Resend CLI, `resend`, `resend doctor`, `resend emails send`, `resend domains`, `resend webhooks listen`, `resend emails receiving`, or agent-friendly terminal automation.

Backend & APIsscripts

alibabacloud-odps-maxframe-coding

Included

Use this skill for MaxFrame SDK development and documentation navigation on Alibaba Cloud MaxCompute (ODPS). Helps answer MaxFrame API, concept, official example, and supported pandas API questions; create data processing programs; read/write MaxCompute tables; debug jobs (remote or local); and build custom DPE runtime images. Trigger when users mention MaxFrame, MaxCompute with MaxFrame, ODPS table processing, DPE runtime, MaxFrame docs/examples, DataFrame/Tensor operations, or GPU runtime setup. Works for both English and Chinese queries about Alibaba Cloud data processing with MaxFrame.

Backend & APIsscripts