Zoom Rtms

RTMS - Webhooks

RTMS-related webhook events and configuration.

CRITICAL: Respond 200 IMMEDIATELY!

The #1 cause of random disconnects:

If your webhook handler takes too long to respond, Zoom assumes failure and retries. The retry creates a second connection, which kicks out your first connection (only 1 connection allowed per stream).

// CORRECT: Respond first, process async
app.post('/webhook', (req, res) => {
  res.status(200).send();  // IMMEDIATELY!

  // Then process asynchronously
  handleRTMSEvent(req.body);
});

// WRONG: Processing before responding
app.post('/webhook', async (req, res) => {
  await heavyProcessing(req.body);  // Zoom may retry while waiting!
  res.status(200).send();
});

URL Validation Challenge

When configuring your webhook URL, Zoom sends a validation challenge:

app.post('/webhook', (req, res) => {
  const { event, payload } = req.body;

  // Handle URL validation
  if (event === 'endpoint.url_validation') {
    const hash = crypto
      .createHmac('sha256', process.env.ZOOM_SECRET_TOKEN)
      .update(payload.plainToken)
      .digest('hex');

    return res.json({
      plainToken: payload.plainToken,
      encryptedToken: hash
    });
  }

  res.status(200).send();
  // ... handle other events
});

Events

meeting.rtms_started

Sent when RTMS stream is ready for a meeting.

{
  "event": "meeting.rtms_started",
  "payload": {
    "account_id": "account_id",
    "object": {
      "meeting_id": "meeting_id",
      "meeting_uuid": "meeting_uuid",
      "host_id": "host_user_id",
      "rtms_stream_id": "stream_id",
      "server_urls": "wss://rtms-sjc1.zoom.us/...",
      "signature": "auth_signature"
    }
  }
}

meeting.rtms_stopped

Sent when RTMS stream ends.

{
  "event": "meeting.rtms_stopped",
  "payload": {
    "account_id": "account_id",
    "object": {
      "meeting_id": "meeting_id",
      "rtms_stream_id": "stream_id"
    }
  }
}

webinar.rtms_started

Sent when RTMS stream is ready for a webinar.

{
  "event": "webinar.rtms_started",
  "payload": {
    "account_id": "account_id",
    "object": {
      "meeting_id": "meeting_id",
      "meeting_uuid": "meeting_uuid",
      "host_id": "host_user_id",
      "rtms_stream_id": "stream_id",
      "server_urls": "wss://rtms-sjc1.zoom.us/...",
      "signature": "auth_signature"
    }
  }
}

Important: Webinar payloads use meeting_uuid, NOT webinar_uuid. The signature and connection flow are identical to meetings.

Webinar-specific considerations:

• Panelists: Full audio/video streams are available for panelists.

• Attendees: View-only participants; individual streams may not be available.

• Practice sessions: Not documented for RTMS.

• Q&A/Polls: Not exposed via RTMS.

webinar.rtms_stopped

Sent when RTMS stream ends for a webinar.

{
  "event": "webinar.rtms_stopped",
  "payload": {
    "account_id": "account_id",
    "object": {
      "meeting_id": "meeting_id",
      "rtms_stream_id": "stream_id"
    }
  }
}

session.rtms_started

Sent when RTMS stream is ready for a Video SDK session.

{
  "event": "session.rtms_started",
  "payload": {
    "account_id": "account_id",
    "object": {
      "session_id": "session_id",
      "rtms_stream_id": "stream_id",
      "server_urls": "wss://rtms-sjc1.zoom.us/...",
      "signature": "auth_signature"
    }
  }
}

Important: Video SDK payloads use session_id instead of meeting_uuid. The HMAC signature must use session_id in place of meeting_uuid.

Video SDK-specific considerations:

• Uses SDK Key/Secret (not OAuth Client ID/Secret) for authentication.

• Requires a Video SDK App (not a General App) in Zoom Marketplace.

• Once connected, the WebSocket protocol is identical to meetings.

session.rtms_stopped

Sent when RTMS stream ends for a Video SDK session.

{
  "event": "session.rtms_stopped",
  "payload": {
    "account_id": "account_id",
    "object": {
      "session_id": "session_id",
      "rtms_stream_id": "stream_id"
    }
  }
}

Screen Share Events (via msg_type 5)

Subscribe to receive SHARING_START and SHARING_STOP events when participants start/stop screen sharing.

Payload Fields

Server URL Geo-Routing

Server URLs contain airport/region codes:

// Extract region from server URL
const hostname = new URL(serverUrl).hostname;  // rtms-sjc1.zoom.us
const region = hostname.split('-')[1].replace(/[0-9]/g, '');  // sjc

Tip: For production, route webhooks to workers in the same region as the Zoom server.

Subscribing to RTMS Events

In Zoom Marketplace (General App - Meetings and Webinars)

1. Go to your app settings

2. Navigate to Features → Access

3. Enable Event Subscription

4. Click Add Event Subscription

5. Enter your webhook endpoint URL

6. Search "rtms" and select:

   • meeting.rtms_started

   • meeting.rtms_stopped

   • webinar.rtms_started (if using webinars)

   • webinar.rtms_stopped (if using webinars)

7. Click Done then Save

In Zoom Marketplace (Video SDK App)

1. Go to your Video SDK app settings

2. Add Event Subscription:

   • session.rtms_started

   • session.rtms_stopped

Required Scopes

For Meetings (Features → Scopes → Add Scopes → search "rtms"):

For Webinars (add these in addition to meeting scopes):

For Video SDK: Uses SDK Key/Secret credentials instead of OAuth scopes.

Products Supporting RTMS

Key differences: Meetings and webinars use a General App with OAuth credentials. Video SDK uses a Video SDK App with SDK Key/Secret. Once connected, the WebSocket protocol is identical across all products.

Resources

• Event reference: https://developers.zoom.us/docs/rtms/event-reference/

• RTMS docs: https://developers.zoom.us/docs/rtms/