Setup Zoom Websockets

# WebSockets - Connection Management

Detailed guide for managing WebSocket connections to Zoom.

## Connection Lifecycle

```
1. Generate access token (S2S OAuth)
         ↓
2. Open WebSocket connection with token
         ↓
3. Receive events in real-time
         ↓
4. Handle disconnects and reconnect
         ↓
5. Close connection when done
```

## Authentication

WebSocket connections require a valid Server-to-Server OAuth access token.

### Generate Access Token

```javascript
const axios = require('axios');

async function getAccessToken(accountId, clientId, clientSecret) {
  const credentials = Buffer.from(`${clientId}:${clientSecret}`).toString('base64');
  
  const response = await axios.post(
    'https://zoom.us/oauth/token',
    new URLSearchParams({
      grant_type: 'account_credentials',
      account_id: accountId
    }),
    {
      headers: {
        'Authorization': `Basic ${credentials}`,
        'Content-Type': 'application/x-www-form-urlencoded'
      }
    }
  );
  
  return {
    accessToken: response.data.access_token,
    expiresIn: response.data.expires_in // Usually 3600 seconds (1 hour)
  };
}
```

### Token Refresh

Access tokens expire after 1 hour. Implement token refresh before expiration:

```javascript
class ZoomWebSocketClient {
  constructor(accountId, clientId, clientSecret, subscriptionId) {
    this.accountId = accountId;
    this.clientId = clientId;
    this.clientSecret = clientSecret;
    this.subscriptionId = subscriptionId;
    this.ws = null;
    this.tokenExpiry = null;
  }
  
  async refreshTokenIfNeeded() {
    const now = Date.now();
    const bufferTime = 5 * 60 * 1000; // 5 minutes before expiry
    
    if (!this.tokenExpiry || now >= this.tokenExpiry - bufferTime) {
      const { accessToken, expiresIn } = await getAccessToken(
        this.accountId, this.clientId, this.clientSecret
      );
      this.accessToken = accessToken;
      this.tokenExpiry = now + (expiresIn * 1000);
      
      // Reconnect with new token
      if (this.ws) {
        this.ws.close();
        await this.connect();
      }
    }
  }
  
  async connect() {
    await this.refreshTokenIfNeeded();
    
    const wsUrl = `wss://ws.zoom.us/ws?subscriptionId=${this.subscriptionId}&access_token=${this.accessToken}`;
    this.ws = new WebSocket(wsUrl);
    
    // Set up event handlers...
  }
}
```

## Connection URL

```
wss://ws.zoom.us/ws?subscriptionId={SUBSCRIPTION_ID}&access_token={ACCESS_TOKEN}
```

| Parameter | Description |
|-----------|-------------|
| `subscriptionId` | Your WebSocket subscription ID from Marketplace |
| `access_token` | Valid S2S OAuth access token |

## Connection Limits

| Limit | Value |
|-------|-------|
| **Connections per subscription** | 1 (opening new connection closes existing) |
| **Connection timeout** | Varies (implement keep-alive) |
| **Message size** | Check Zoom docs for current limits |

## Keep-Alive / Heartbeat

Maintain connection with periodic pings:

```javascript
class WebSocketManager {
  constructor() {
    this.ws = null;
    this.pingInterval = null;
  }
  
  startHeartbeat() {
    // Ping every 30 seconds
    this.pingInterval = setInterval(() => {
      if (this.ws && this.ws.readyState === WebSocket.OPEN) {
        this.ws.ping();
        console.log('Ping sent');
      }
    }, 30000);
  }
  
  stopHeartbeat() {
    if (this.pingInterval) {
      clearInterval(this.pingInterval);
      this.pingInterval = null;
    }
  }
  
  connect(url) {
    this.ws = new WebSocket(url);
    
    this.ws.on('open', () => {
      console.log('Connected');
      this.startHeartbeat();
    });
    
    this.ws.on('pong', () => {
      console.log('Pong received - connection alive');
    });
    
    this.ws.on('close', () => {
      this.stopHeartbeat();
    });
  }
}
```

## Reconnection Strategy

Implement exponential backoff for reconnection:

```javascript
class ReconnectingWebSocket {
  constructor(config) {
    this.config = config;
    this.ws = null;