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:

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, don't use the Data Layer API as the primary way to communicate with a network. Instead, follow the same pattern as in mobile apps, with some minor differences.

Use a minimal client

A minimal client, as shown in the following example, is enough to begin. See Access Google 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. This lets certain interactions appear as dialogs rather than as notifications, such as when 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:

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);

See the WearableOptions.Builder reference for more information.

Wearable API clients, such as DataClient and MessageClient, are inexpensive to create. The API clients don't need to be held onto, so you can create them as many times as you need. 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.