Set up a Firebase Cloud Messaging client app on Android

FCM clients require devices running Android 5.0 or higher that also have the Google Play Store app installed, or an emulator running Android 5.0 with Google APIs. Note that you are not limited to deploying your Android apps through Google Play Store.

Set up the SDK

This section covers tasks you may have completed if you have already enabled other Firebase features for your app. If you haven't already, add Firebase to your Android project

Edit your app manifest

Add the following to your app's manifest:

  • A service that extends FirebaseMessagingService. This is required if you want to do any message handling beyond receiving notifications on apps in the background. To receive notifications in foregrounded apps, to receive data payload, to send upstream messages, and so on, you must extend this service.
    • <service
    android:name=".java.MyFirebaseMessagingService"
    android:exported="false">
    <intent-filter>
        <action android:name="com.google.firebase.MESSAGING_EVENT" />
    </intent-filter>
</service>
    AndroidManifest.xml
  • (Optional) Within the application component, metadata elements to set a default notification icon and color. Android uses these values whenever incoming messages do not explicitly set icon or color.
    • <!-- Set custom default icon. This is used when no icon is set for incoming notification messages.
     See README(https://goo.gl/l4GJaQ) for more. -->
<meta-data
    android:name="com.google.firebase.messaging.default_notification_icon"
    android:resource="@drawable/ic_stat_ic_notification" />
<!-- Set color used with incoming notification messages. This is used when no color is set for the incoming
     notification message. See README(https://goo.gl/6BKBk7) for more. -->
<meta-data
    android:name="com.google.firebase.messaging.default_notification_color"
    android:resource="@color/colorAccent" />
    AndroidManifest.xml
  • (Optional) From Android 8.0 (API level 26) and higher, notification channels are supported and recommended. FCM provides a default notification channel with basic settings. If you prefer to create and use your own default channel, set default_notification_channel_id to the ID of your notification channel object as shown; FCM will use this value whenever incoming messages do not explicitly set a notification channel. To learn more, see Manage notification channels. 
    • <meta-data
    android:name="com.google.firebase.messaging.default_notification_channel_id"
    android:value="@string/default_notification_channel_id" />
    AndroidManifest.xml

Request runtime notification permission on Android 13+

Android 13 introduces a new runtime permission for showing notifications. This affects all apps running on Android 13 or higher that use FCM notifications.

By default, the FCM SDK (version 23.0.6 or higher) includes the POST_NOTIFICATIONS permission defined in the manifest. However, your app will also need to request the runtime version of this permission via the constant, android.permission.POST_NOTIFICATIONS. Your app will not be allowed to show notifications until the user has granted this permission.

To request the new runtime permission:

Kotlin

// Declare the launcher at the top of your Activity/Fragment:
private val requestPermissionLauncher = registerForActivityResult(
    ActivityResultContracts.RequestPermission(),
) { isGranted: Boolean ->
    if (isGranted) {
        // FCM SDK (and your app) can post notifications.
    } else {
        // TODO: Inform user that that your app will not show notifications.
    }
}

private fun askNotificationPermission() {
    // This is only necessary for API level >= 33 (TIRAMISU)
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
        if (ContextCompat.checkSelfPermission(this, Manifest.permission.POST_NOTIFICATIONS) ==
            PackageManager.PERMISSION_GRANTED
        ) {
            // FCM SDK (and your app) can post notifications.
        } else if (shouldShowRequestPermissionRationale(Manifest.permission.POST_NOTIFICATIONS)) {
            // TODO: display an educational UI explaining to the user the features that will be enabled
            //       by them granting the POST_NOTIFICATION permission. This UI should provide the user
            //       "OK" and "No thanks" buttons. If the user selects "OK," directly request the permission.
            //       If the user selects "No thanks," allow the user to continue without notifications.
        } else {
            // Directly ask for the permission
            requestPermissionLauncher.launch(Manifest.permission.POST_NOTIFICATIONS)
        }
    }
}
MainActivity.kt

Java

// Declare the launcher at the top of your Activity/Fragment:
private final ActivityResultLauncher<String> requestPermissionLauncher =
        registerForActivityResult(new ActivityResultContracts.RequestPermission(), isGranted -> {
            if (isGranted) {
                // FCM SDK (and your app) can post notifications.
            } else {
                // TODO: Inform user that that your app will not show notifications.
            }
        });

private void askNotificationPermission() {
    // This is only necessary for API level >= 33 (TIRAMISU)
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
        if (ContextCompat.checkSelfPermission(this, Manifest.permission.POST_NOTIFICATIONS) ==
                PackageManager.PERMISSION_GRANTED) {
            // FCM SDK (and your app) can post notifications.
        } else if (shouldShowRequestPermissionRationale(Manifest.permission.POST_NOTIFICATIONS)) {
            // TODO: display an educational UI explaining to the user the features that will be enabled
            //       by them granting the POST_NOTIFICATION permission. This UI should provide the user
            //       "OK" and "No thanks" buttons. If the user selects "OK," directly request the permission.
            //       If the user selects "No thanks," allow the user to continue without notifications.
        } else {
            // Directly ask for the permission
            requestPermissionLauncher.launch(Manifest.permission.POST_NOTIFICATIONS);
        }
    }
}
MainActivity.java

Generally, you should display a UI explaining to the user the features that will be enabled if they grant permissions for the app to post notifications. This UI should provide the user options to agree or deny, such as OK and No thanks buttons. If the user selects OK, directly request the permission. If the user selects No thanks, allow the user to continue without notifications.

See Notification runtime permission for more best practices on when your app should request the POST_NOTIFICATIONS permission from the user.

Notification permissions for apps targeting Android 12L (API level 32) or lower

Android automatically asks the user for permission the first time your app creates a notification channel, as long as the app is in the foreground. However, there are important caveats regarding the timing of channel creation and permission requests:

  • If your app creates its first notification channel when it is running in the background (which the FCM SDK does when receiving an FCM notification), Android will not allow the notification to be displayed and will not prompt the user for the notification permission until the next time your app is opened. This means that any notifications received before your app is opened and the user accepts the permission will be lost.
  • We strongly recommend that you update your app to target Android 13+ to take advantage of the platform’s APIs to request permission. If that is not possible, your app should create notification channels before you send any notifications to the app in order to trigger the notification permission dialog and ensure no notifications are lost. See notification permission best practices for more information.

Optional: remove POST_NOTIFICATIONS permission

By default, the FCM SDK includes the POST_NOTIFICATIONS permission. If your app does not use notification messages (whether through FCM notifications, through another SDK, or directly posted by your app) and you don’t want your app to include the permission, you can remove it using the manifest merger’s remove marker. Keep in mind that removing this permission prevents the display of all notifications, not just FCM notifications. Add the following to your app’s manifest file:

<uses-permission android:name="android.permission.POST_NOTIFICATIONS" tools:node="remove"/>

Access the device registration token

On initial startup of your app, the FCM SDK generates a registration token for the client app instance. If you want to target single devices or create device groups, you'll need to access this token by extending FirebaseMessagingService and overriding onNewToken.

This section describes how to retrieve the token and how to monitor changes to the token. Because the token could be rotated after initial startup, you are strongly recommended to retrieve the latest updated registration token.

The registration token may change when:

  • The app is restored on a new device
  • The user uninstalls/reinstall the app
  • The user clears app data.

Retrieve the current registration token

When you need to retrieve the current token, call FirebaseMessaging.getInstance().getToken():

Kotlin

FirebaseMessaging.getInstance().token.addOnCompleteListener(OnCompleteListener { task ->
    if (!task.isSuccessful) {
        Log.w(TAG, "Fetching FCM registration token failed", task.exception)
        return@OnCompleteListener
    }

    // Get new FCM registration token
    val token = task.result

    // Log and toast
    val msg = getString(R.string.msg_token_fmt, token)
    Log.d(TAG, msg)
    Toast.makeText(baseContext, msg, Toast.LENGTH_SHORT).show()
})

Java

FirebaseMessaging.getInstance().getToken()
    .addOnCompleteListener(new OnCompleteListener<String>() {
        @Override
        public void onComplete(@NonNull Task<String> task) {
          if (!task.isSuccessful()) {
            Log.w(TAG, "Fetching FCM registration token failed", task.getException());
            return;
          }

          // Get new FCM registration token
          String token = task.getResult();

          // Log and toast
          String msg = getString(R.string.msg_token_fmt, token);
          Log.d(TAG, msg);
          Toast.makeText(MainActivity.this, msg, Toast.LENGTH_SHORT).show();
        }
    });

Monitor token generation

The onNewToken callback fires whenever a new token is generated.

Kotlin

/**
 * Called if the FCM registration token is updated. This may occur if the security of
 * the previous token had been compromised. Note that this is called when the
 * FCM registration token is initially generated so this is where you would retrieve the token.
 */
override fun onNewToken(token: String) {
    Log.d(TAG, "Refreshed token: $token")

    // If you want to send messages to this application instance or
    // manage this apps subscriptions on the server side, send the
    // FCM registration token to your app server.
    sendRegistrationToServer(token)
}
MyFirebaseMessagingService.kt

Java

/**
 * There are two scenarios when onNewToken is called:
 * 1) When a new token is generated on initial app startup
 * 2) Whenever an existing token is changed
 * Under #2, there are three scenarios when the existing token is changed:
 * A) App is restored to a new device
 * B) User uninstalls/reinstalls the app
 * C) User clears app data
 */
@Override
public void onNewToken(@NonNull String token) {
    Log.d(TAG, "Refreshed token: " + token);

    // If you want to send messages to this application instance or
    // manage this apps subscriptions on the server side, send the
    // FCM registration token to your app server.
    sendRegistrationToServer(token);
}
MyFirebaseMessagingService.java

After you've obtained the token, you can send it to your app server and store it using your preferred method.

Check for Google Play services

Apps that rely on the Play Services SDK should always check the device for a compatible Google Play services APK before accessing Google Play services features. It is recommended to do this in two places: in the main activity's onCreate() method, and in its onResume() method. The check in onCreate() ensures that the app can't be used without a successful check. The check in onResume() ensures that if the user returns to the running app through some other means, such as through the back button, the check is still performed.

If the device doesn't have a compatible version of Google Play services, your app can call GoogleApiAvailability.makeGooglePlayServicesAvailable() to allow users to download Google Play services from the Play Store.

Prevent auto initialization

When an FCM registration token is generated, the library uploads the identifier and configuration data to Firebase. If you prefer to prevent token autogeneration, disable Analytics collection and FCM auto initialization (you must disable both) by adding these metadata values to your AndroidManifest.xml:

<meta-data
    android:name="firebase_messaging_auto_init_enabled"
    android:value="false" />
<meta-data
    android:name="firebase_analytics_collection_enabled"
    android:value="false" />
AndroidManifest.xml

To re-enable FCM auto-init, make a runtime call:

Kotlin

Firebase.messaging.isAutoInitEnabled = true
MainActivity.kt

Java

FirebaseMessaging.getInstance().setAutoInitEnabled(true);
MainActivity.java

To re-enable Analytics collection, call the setAnalyticsCollectionEnabled() method of the FirebaseAnalytics class. For example:

setAnalyticsCollectionEnabled(true);

These values persist across app restarts once set.

Next steps

After the client app is set up, you are ready to start sending downstream messages with the Notifications composer. This functionality is demonstrated in the quickstart sample, which you can download, run, and review.

To add other, more advanced behavior to your app, you can declare an intent filter and implement an activity to respond to incoming messages. For details, see the guides for sending messages from an app server:

Keep in mind that, to take advantage of these features, you'll need a server implementation and the server procotols (HTTP or XMPP), or an implementation of the Admin SDK.