Implement the Co-Watching API

The Co-Watching API manages the meeting experience of multiple participants watching or listening to content in your app.

This guide explains how to implement the Co-Watching API.

Get started

To use the Co-Watching API, you first must Deploy a Meet add-on. Once you've completed those steps, you can start using the Co-Watching API from within your new add-on.

To use the Co-Watching API, start by getting an AddonSession object, which serves as the entry point for Google Meet co-activities:

const session = await window.meet.addon.createAddonSession({
    cloudProjectNumber: "CLOUD_PROJECT_NUMBER",
});

Create a co-watching client

To get started, create a CoWatchingClient object from your AddonSession.

To create a CoWatchingCient, call the createCoWatchingClient() method and provide a CoWatchingDelegate object.

The CoWatchingDelegate is how the Co-Watching API updates your app whenever it has a new state available. It's expected that, when the onCoWatchingStateChanged() method is called, your app immediately applies the new state.

The following code sample shows how to use the Co-Watching API:

 const coWatchingClient = await addonSession.createCoWatchingClient({
    activityTitle: "ACTIVITY_TITLE",
    onCoWatchingStateQuery() {
      // This function should return the current state of your CoWatching activity
      return getMyApplicationCoWatchingState();
    },
    onCoWatchingStateChanged(coWatchingState: CoWatchingState) {
      // This function should apply newState to your ongoing CoWatching activity
    },
  });

Manage current state

When users take action in your application, it's expected that your application immediately calls the provided API methods.

You should only call these methods in response to significant events. For example, you don't need to call them every time your app advances a playing video. The CoWatchingDelegate you create handles getting updated playout positions in these circumstances.

You can control the co-watching state using these methods:

• notifyBuffering(): Call when a user's app starts buffering due to buffering from a prior media switch, media seek, or network congestion.

• notifyPauseState(): Call when a user pauses or unpauses the playing media.

• notifyPlayoutRate(): Call when a user updates the playback speed to a new value (for example, 1.25x).

• notifyReady(): Call when buffering completes and the media is now ready to be played.

• notifySeekToTimestamp(): Call when a user explicitly changes the play out position.

• notifySwitchToMedia(): Call whenever the actively playing media changes. For example, the user selects a new video, or autoplay starts the next video.