Access the Wearable Data Layer

To call the Data Layer API, use the Wearable class to get instances of the various client classes, such as DataClient and MessageClient.

Refer to the following related resources:

• Data Layer sample

Note: The Data Layer API can only send messages and synchronize data with Android devices or Wear OS watches. That means if your Wear OS device is paired with an iOS device, the Data Layer API won't work.

For this reason, you shouldn't use the Data Layer API as the primary way to communicate with a network. Instead, your app should follow the same pattern as a mobile app with some minor differences.

Use a minimal client

A minimal client, as shown in the following example, is enough to begin. See Access Google Play services APIs for additional information:

Kotlin

val dataClient: DataClient = Wearable.getDataClient(context)

Java

DataClient dataClient = Wearable.getDataClient(context);

The context can be any valid Android context. If you are using the API within the scope of an Activity, use the getDataClient(activity) method of the Wearable class, which allows certain interactions to appear as dialogs rather than as notifications, e.g., if the user is asked to update their version of Google Play services.

By default, callbacks to listeners are made on the app's main UI thread. To have callbacks made on a different thread, use a WearableOptions object to specify a custom Looper (see WearableOptions.Builder):

Kotlin

val dataClient: DataClient =
        Wearable.WearableOptions.Builder().setLooper(myLooper).build().let { options ->
            Wearable.getDataClient(context, options)
        }

Java

WearableOptions options = new WearableOptions.Builder().setLooper(myLooper).build();
DataClient dataClient = Wearable.getDataClient(context, options);

Wearable API clients, such as DataClient and MessageClient, are inexpensive to create and don't need to be created only once and held onto. Use the style that suits your app. The client state, such as the set of registered listeners, is shared across all clients, and is preserved if Google Play services is updated while an app is running.