---
name: dev-multiplayer-colyseus-server
description: Colyseus server setup, room handlers, lifecycle events, and scaling. Use when setting up multiplayer server.
category: multiplayer
---

# Colyseus Server Setup

Node.js multiplayer framework - authoritative game server with real-time state sync.

## When to Use

Use when:
- Setting up Colyseus server
- Creating room handlers
- Implementing matchmaking
- Configuring server transport

## Server Setup (ESM Required)

```typescript
// server/index.ts - MUST use ESM
import { Server } from 'colyseus';
import { createServer } from 'http';
import express from 'express';
import { WebSocketTransport } from '@colyseus/ws-transport';
import { GameRoom } from './rooms/GameRoom';

const port = Number(process.env.PORT) || 2567;

const app = express();

// CORS middleware
app.use((req, res, next) => {
  res.setHeader('Access-Control-Allow-Origin', '*');
  res.setHeader('Access-Control-Allow-Methods', 'GET, POST, PUT, DELETE, OPTIONS');
  res.setHeader('Access-Control-Allow-Headers', 'Content-Type, Authorization');
  if (req.method === 'OPTIONS') {
    res.writeHead(200);
    res.end();
    return;
  }
  next();
});

const httpServer = createServer(app);

const gameServer = new Server({
  transport: new WebSocketTransport({ server: httpServer }),
});

gameServer.define('game_room', GameRoom);
gameServer.listen(port);

console.log(`Colyseus server listening on wss://localhost:${port}`);
```

**CRITICAL**: Server MUST use `"type": "module"` in package.json. Do NOT use CommonJS.

## Room Handler Definition

```typescript
import { Room, Client } from 'colyseus';
import { Schema, type, MapSchema } from '@colyseus/schema';

export class GameRoom extends Room<GameRoomState> {
  onCreate(options: any) {
    this.setState(new GameRoomState());
    console.log(`[GameRoom] Created: ${this.roomId}`);

    // Simulation tick (deltaTime in seconds)
    this.setSimulationInterval((deltaTime) => {
      this.update(deltaTime);
    });

    // One-time event
    this.clock.setTimeout(() => this.endMatch(), 5000);

    // Repeated event
    this.clock.setInterval(() => this.checkCondition(), 100);
  }

  onJoin(client: Client, options: any) {
    const player = new PlayerState();
    player.clientId = client.sessionId;
    this.state.players.set(client.sessionId, player);

    client.send('welcome', { playerId: client.sessionId });
  }

  onLeave(client: Client, consented: boolean) {
    this.state.players.delete(client.sessionId);
  }

  onMessage(client: Client, data: any) {
    switch (data.type) {
      case 'player_input':
        this.handleInput(client, data);
        break;
    }
  }

  onDispose() {
    console.log(`[GameRoom] Disposed: ${this.roomId}`);
  }
}
```

## Message Broadcasting

```typescript
// Broadcast to all clients
this.broadcast('game_event', { data: 'value' });

// Send to specific client
client.send('personal_event', { data: 'value' });

// Send to all except sender
this.broadcast('game_event', { data: 'value' }, [client.sessionId]);
```

## Server Definition Options

```typescript
// Filter rooms by options for matchmaking
gameServer
  .define('battle', BattleRoom)
  .filterBy(['mode', 'map']);

// Sort rooms for matchmaking priority
gameServer
  .define('battle', BattleRoom)
  .sortBy({ clients: -1 });  // Most players first

// Enable realtime listing
gameServer
  .define('battle', BattleRoom)
  .enableRealtimeListing();

// Listen to lifecycle events
gameServer
  .define('chat', ChatRoom)
  .on('create', (room) => console.log('Room created'))
  .on('dispose', (room) => console.log('Room disposed'))
  .on('join', (room, client) => console.log('Client joined'))
  .on('leave', (room, client) => console.log('Client left'));
```

## Transport Configuration

```typescript
import { WebSocketTransport } from '@colyseus/ws-transport';

new WebSocketTransport({
  server,                // HTTP server instance
  pingInterval: 30000,    // Ping interval (ms)
  pingMaxRetries: 3,      // Max retries before disconnect
});

// Development: simulate latency
if (process.env.NODE_ENV !== 'production') {
  gameServer.simulateLatency(200);
}
```

## Scaling with Redis

```typescript
import { Server, RedisPresence, RedisDriver } from 'colyseus';

const gameServer = new Server({
  presence: new RedisPresence(),  // Multi-process communication
  driver: new RedisDriver(),       // Room storage across processes
});
```

## Best Practices

1. **Always use ESM** - `"type": "module"` in package.json
2. **Validate all inputs** - Never trust client data
3. **Rate limit actions** - Prevent spam exploits
4. **Log room lifecycle** - For debugging
5. **Use Schema for state** - Efficient binary serialization

## Common Mistakes

| ❌ Wrong | ✅ Right |
|----------|----------|
| `require/module.exports` | `import/export` with `"type": "module"` |
| Server using `colyseus.js` | Server uses `colyseus` package |
| Trusting client positions | Validate all inputs server-side |

## Reference

- [Colyseus Server Docs](https://docs.colyseus.io/server)
- [Room Handlers](https://docs.colyseus.io/server/room/)

---

## Room Lifecycle Best Practices (Updated 2026-01-28)

From arch-003 retrospective - proven patterns for Colyseus room implementation.

### Lifecycle Event Order

```
onCreate (once) → onAuth (per client) → onJoin (per client) → onMessage (loop)
→ onLeave (per client) → onDispose (once, when no clients)
```

### onCreate Implementation Pattern

```typescript
import { Room, Client } from 'colyseus';
import { MyRoomState } from '../schema/MyRoomState';

export class MyRoom extends Room<MyRoomState> {
  maxClients = 64;  // Set on class for 64-player FFA

  onCreate(options: any) {
    // 1. Initialize state
    this.setState(new MyRoomState());

    // 2. Set patch rate (20Hz = 50ms for multiplayer games)
    this.setPatchRate(50);  // 50ms = 20 ticks/sec

    // 3. Set up simulation interval (optional game loop)
    this.setSimulationInterval((deltaTime) => {
      this.gameLoop(deltaTime);
    });

    // 4. Register message handlers
    this.onMessage('input', (client, data) => {
      this.handlePlayerInput(client, data);
    });

    console.log(`[Room ${this.roomId}] Created with options:`, options);
  }

  onAuth(client: Client, options: any): boolean | Promise<any> {
    // Return true to allow, false/error to reject
    // Can return Promise for async validation
    return true;
  }

  onJoin(client: Client, options: any) {
    console.log(`[Room ${this.roomId}] Client joined: ${client.sessionId}`);

    // Create player state
    const player = new PlayerState();
    player.sessionId = client.sessionId;
    this.state.players.set(client.sessionId, player);

    // Send welcome message
    client.send('welcome', { sessionId: client.sessionId });
  }

  onLeave(client: Client, consented: boolean) {
    console.log(`[Room ${this.roomId}] Client left: ${client.sessionId} (consented: ${consented})`);

    // Remove player from state
    this.state.players.delete(client.sessionId);
  }

  onDispose() {
    console.log(`[Room ${this.roomId}] Disposed`);
  }

  private gameLoop(deltaTime: number) {
    // Game logic here
  }
}
```

### Room Configuration Best Practices

| Configuration | Value | Purpose |
|--------------|-------|---------|
| `maxClients` | 64 | FFA mode capacity |
| `patchRate` | 50ms | 20Hz state sync for multiplayer |
| `autoDispose` | true | Cleanup when empty (default) |
| `setSimulationInterval` | 16.6ms | 60Hz game loop (optional) |

### Message Handler Pattern

```typescript
// Specific message type
this.onMessage('move', (client, data) => {
  const player = this.state.players.get(client.sessionId);
  if (player) {
    player.x = data.x;
    player.y = data.y;
  }
});

// Catch-all for other messages
this.onMessage('*', (client, type, data) => {
  console.log(`Unhandled message: ${type}`, data);
});
```

**Sources:**
- https://docs.colyseus.io/colyseus/server/room/
- **Learned from arch-003 retrospective (2026-01-28)**


---
Source attribution: feliperyba
Original project: https://github.com/feliperyba/ralph-orchestra/blob/7a74951367fe9bec093753f6eaa4d0eeda9428e5/.claude/skills/dev-multiplayer-colyseus-server/SKILL.md
License: MIT
License information: https://opensource.org/license/mit
Original upstream instructions; downloaded from Dave AI.

## Upstream license notice

MIT License

Copyright (c) 2026 feliperyba

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.



# Dave AI resource metadata

Creator / publisher: feliperyba
Original project: https://github.com/feliperyba/ralph-orchestra/blob/7a74951367fe9bec093753f6eaa4d0eeda9428e5/.claude/skills/dev-multiplayer-colyseus-server/SKILL.md
Attribution basis: Recovered original package and original project license at a pinned revision

Fields of work: Development & Engineering
Roles: Backend Developer, Full-Stack Developer, Game Developer
Specialties: Backend
Tools: Colyseus
Country applicability: Country not specified
Classification basis: Source catalog labels
Instruction SHA-256: 04da1944598da5657c3dbe1df0d0955281d54f55cf11567563e8d6cc2b241e74
Metadata reviewed: 2026-10-27
This metadata supersedes earlier Dave AI catalog attribution. Original instruction and supporting files are preserved.