Working with streams

Each Realtime Media Streams (RTMS) stream follows a predictable flow that starts with at least one session being started; continues while your app connects to the required servers, receives stream data, and maintains connection; and ends when the stream ends. A stream can have multiple sessions happening within it, each session typically corresponds to an individual user.

Sessions can exist in the following states:

This diagram outlines the lifecycle of an RTMS stream during a meeting or webinar.

Prerequisites#

To process RTMS data, you need to add RTMS features to your app. Your app needs the appropriate event subscriptions, scopes, and, optionally, the JavaScript SDK or REST APIs for starting and managing sessions. For more information, see Add RTMS features to your app.

Once your app is configured, RTMS sessions will follow these steps:

Step 1: RTMS is started#

RTMS provides role-based controls to manage the streaming experience. You can set their apps to auto-start streams when the user joins a meeting, or webinar, or to start manually by using the REST API or JavaScript SDK.

In addition, the streaming experience is also controlled by:

• Admins can manage the auto-start settings for users, groups, or the entire account in the Zoom web portal.

• Hosts can allow or deny RTMS start requests for each meeting or webinar, or choose Always allow in my meetings so their approval persists across the meetings and webinars they host.

• Participants can manually start, pause, and end their own streams. (Requires host approval.)

import zoomSdk from '@zoom/appssdk';

(async () => {
    try {
        const configResponse = await zoomSdk.config({
            capabilities: ['startRTMS'],
        });

        const { runningContext } = configResponse;
        if (runningContext === 'inMeeting') {
            const rtmsResponse = await zoomSdk.callZoomApi('startRTMS');
            console.debug('RTMS Start Response:', rtmsResponse);
        }
    } catch (e) {
        console.error('Zoom SDK Error:', e);
    }
})();

Step 2: App receives streaming notification#

Zoom sends meeting.rtms_started, or webinar.rtms_started, webhook events when RTMS streaming starts. You can then use the information in the event to establish a signaling connection in the next step.

To receive notifications when new streams are available, create an HTTP POST handler in your web app. This handler acts as the endpoint for incoming webhook events. In your app settings, provide the URL of this endpoint.

After you receive an event, verify the event's signature to ensure it's from a trusted source.

Step 3: App establishes signaling connection#

Establishing a signal connection to an RTMS server enables your app to establish and manage a WebSocket connection with the RTMS server. It begins with a signed handshake and includes messages for session readiness, state updates, and stream control.

The signal connection provides lifecycle updates for the media connection, such as when it starts, stops, or encounters an event.

When you have the connection details and know a stream is available, you can start the connection to the signaling server.

1. Run the following command to create a signature that your app will use to securely connect to the RTMS server; replacing client_id and secret with your app's Client ID and Client Secret, and meeting_uuid and rtms_stream_id with the meeting_uuid, or webinar_id, and rtms_stream_id from the streaming notification event.

   HMACSHA256(client_id + ',' + meeting_uuid + ',' + rtms_stream_id, secret);
   

2. Your app sends a signaling handshake request with the meeting_uuid, or webinar_uuid, and rtms_stream_id from the streaming notification event and the signature you just created. If the handshake is successful, your app will receive a signaling handshake response confirming the connection and containing the media server locations.

   If the handshake fails, the server responds with a SIGNALING_HAND_SHAKE_RESP message containing a status code and reason.

3. (Optional) Your app can Subscribe to events for participant changes and active speaker updates.

Once your app has successfully established a signaling connection, it can now establish a media connection.

Step 4: App establishes the media connection#

Use one of the URLs list in media_server.server_urls in the signaling handshake response to establish a media WebSocket connection.

1. Your app sends a media handshake request with the meeting_uuid, or webinar_uuid, and rtms_stream_id from the streaming notification and the signature you created in Step 3 above. If the handshake is successful, your app will receive a media handshake response confirming the connection and containing information about the available media.

   If the handshake fails, the server responds with a SIGNALING_HAND_SHAKE_RESP message containing a status code and reason.

2. Your app sends a client ready ACK message to the RTMS server media connection to indicate readiness to receive media.

Now that the connection is made, your app can receive media data.

Step 5: App receives media data#

Once the connection is established, your app receives continuous streams of:

• Audio data from participants
• Video data from active speakers or a specific individual
• Transcript data from spoken audio
• In-meeting events for participant changes and active speaker updates

By default, video streams the active speaker. To stream a specific participant's video instead, see Stream a single participant's video.

For more information about working with media data, see Handling media data.

Step 6: App maintains connections#

Throughout the session, your app must:

• Respond to keep-alive requests to maintain stable connections (sent every 10 seconds when no data is flowing)
• Monitor session state updates for pauses, resumes, or interruptions
• Handle stream state changes for connection issues or termination

If a connection has been interrupted, see Failover and reconnection for more information on reestablishing the connection.

Step 7: Stream ends#

The RTMS stream ends when:

• The meeting or webinar concludes
• The user manually stops streaming
• The host disables RTMS
• Connection issues cause termination
• App users leave the meeting or webinar

Your app receives a meeting.rtms_stopped, or webinar.rtms_stopped, notification indicating the stream has ended.