Set up a Firebase Cloud Messaging client app with C++

To write your cross-platform Firebase Cloud Messaging client app with C++, use the Firebase Cloud Messaging API. The C++ SDK works for both Android and Apple platforms, with some additional setup required for each platform.

Set up Firebase and the FCM SDK


  1. If you haven't already, add Firebase to your C++ project.

    • In the linked setup instructions, review the device and app requirements for using the Firebase C++ SDK, including the recommendation to use CMake to build your app.

    • In your project-level build.gradle file, make sure to include Google's Maven repository in both your buildscript and allprojects sections.

  2. Create a Firebase App object, passing in the JNI environment and Activity:

    app = ::firebase::App::Create(::firebase::AppOptions(), jni_env, activity);

  3. Define a class that implements the firebase::messaging::Listener interface.

  4. Initialize FCM, passing in the App and a constructed Listener:

    ::firebase::messaging::Initialize(app, listener);

  5. Apps that rely on the Google Play services SDK should check the device for a compatible Google Play services APK before accessing the features. To learn more, refer to Check for Google Play services APK.


  1. If you haven't already, add Firebase to your C++ project. Then, to set up your project for FCM:
    1. In your project's Podfile, add the FCM dependency:
      pod 'FirebaseMessaging'
    2. Drag the firebase.framework and firebase_messaging.framework frameworks into your Xcode project from the Firebase C++ SDK.
  2. Upload your APNs authentication key to Firebase. If you don't already have an APNs authentication key, make sure to create one in the Apple Developer Member Center.

    1. Inside your project in the Firebase console, select the gear icon, select Project Settings, and then select the Cloud Messaging tab.

    2. In APNs authentication key under iOS app configuration, click the Upload button.

    3. Browse to the location where you saved your key, select it, and click Open. Add the key ID for the key (available in the Apple Developer Member Center) and click Upload.

  3. Configure your Xcode project to enable Push Notifications:

    1. Select the project from the Navigator area.
    2. Select the project target from the Editor area.
    3. Select the General tab from the Editor area.

      1. Scroll down to Linked Frameworks and Libraries, then click the + button to add frameworks.
      2. In the window that appears, scroll to UserNotifications.framework, click on that entry, then click Add.

        This framework only appears in Xcode v8 and later and is required by this library.

    4. Select the Capabilities tab from the Editor area.

      1. Switch Push Notifications to On.
      2. Scroll down to Background Modes, then switch it to On.
      3. Select Remote notifications under Background Modes.
  4. Create a Firebase App object:

    app = ::firebase::App::Create(::firebase::AppOptions());

  5. Define a class that implements the firebase::messaging::Listener interface.

  6. Initialize Firebase Cloud Messaging, passing in the App and a constructed Listener:

    ::firebase::messaging::Initialize(app, listener);

Access the device registration token

Upon initializing the Firebase Cloud Messaging library, a registration token is requested for the client app instance. The app will receive the token with the OnTokenReceived callback, which should be defined in the class that implements firebase::messaging::Listener.

If you want to target that specific device, you'll need access to this token.

Note about message delivery on Android

When the app is not running at all and a user taps on a notification, the message is not, by default, routed through FCM's built in callbacks. In this case, message payloads are received through an Intent used to start the application. To have FCM forward these incoming messages to the C++ library callback, you need to override the method onNewIntent in your Activity and pass the Intent to the MessageForwardingService.


class MyActivity extends Activity {
  private static final String TAG = "MyActvity";

  protected void onNewIntent(Intent intent) {
    Log.d(TAG, "A message was sent to this app while it was in the background.");
    Intent message = new Intent(this, MessageForwardingService.class);
    // For older versions of Firebase C++ SDK (< 7.1.0), use `startService`.
    // startService(message);
    MessageForwardingService.enqueueWork(this, message);

Messages received while the app is in the background have the content of their notification field used to populate the system tray notification, but that notification content will not be communicated to FCM. That is, Message::notification will be a null.

In summary:

App state Notification Data Both
Foreground OnMessageReceived OnMessageReceived OnMessageReceived
Background System tray OnMessageReceived Notification: system tray
Data: in extras of the intent.

Custom Message Handling on Android

By default, notifications sent to the app are passed to ::firebase::messaging::Listener::OnMessageReceived, but in some cases you may want to override the default behavior. To do this on Android you will need to write custom classes that extend as well as update your project's AndroidManifest.xml.

Override ListenerService Methods.

The ListenerService is the Java class that intercepts incoming messages sent to the app and routes them to the C++ library. When the app is in the foreground (or when the app is the background and it receives a data-only payload), messages will pass through one of the callbacks provided on this class. To add custom behavior to the message handling, you will need to extend FCM's default ListenerService:


class MyListenerService extends ListenerService {

By overriding the method ListenerService.onMessageReceived, you can perform actions based on the received RemoteMessage object and get the message data:

public void onMessageReceived(RemoteMessage message) {
  Log.d(TAG, "A message has been received.");
  // Do additional logic...

ListenerService also has a few other methods that are used less frequently. These can be overridden as well, for more information see the FirebaseMessagingService reference.

public void onDeletedMessages() {
  Log.d(TAG, "Messages have been deleted on the server.");
  // Do additional logic...

public void onMessageSent(String messageId) {
  Log.d(TAG, "An outgoing message has been sent.");
  // Do additional logic...

public void onSendError(String messageId, Exception exception) {
  Log.d(TAG, "An outgoing message encountered an error.");
  // Do additional logic...
  super.onSendError(messageId, exception);

Update AndroidManifest.xml

Once your custom classes have been written, they must be included in the AndroidManifest.xml to take effect. Ensure that the manifest includes the merge tools by declaring the appropriate attribute inside the <manifest> tag, like so:

<manifest xmlns:android=""

In the firebase_messaging_cpp.aar archive there is an AndroidManifest.xml file which declares FCM's default ListenerService. This manifest is normally merged with the project specific manifest which is how the ListenerService is able to run. This ListenerService needs to replaced with the cusom listener service. That is accomplished by removing the default ListenerService and adding the custom Service, which can be done with the following lines your projects AndroidManifest.xml file:

<service android:name=""
         tools:node="remove" />
<service android:name=""
    <action android:name=""/>

New versions of Firebase C++ SDK (7.1.0 onwards) use JobIntentService which requires additional modifications in AndroidManifest.xml file.

<service android:name=""
     android:exported="false" >

Prevent auto initialization

FCM generates a registration token for device targeting. When a token is generated, the library uploads the identifier and configuration data to Firebase. If you want to get an explicit opt-in before using the token, you can prevent generation at configure time by disabling FCM (and on Android, Analytics). To do this, add a metadata value to your Info.plist (not your GoogleService-Info.plist) on Apple platforms, or your AndroidManifest.xml on Android:


<?xml version="1.0" encoding="utf-8"?>
  <meta-data android:name="firebase_messaging_auto_init_enabled"
             android:value="false" />
  <meta-data android:name="firebase_analytics_collection_enabled"
             android:value="false" />


FirebaseMessagingAutoInitEnabled = NO

To re-enable FCM, you can make a runtime call:


This value persists across app restarts once set.

FCM allows messages to be sent containing a deep link into your app. To receive messages that contain a deep link, you must add a new intent filter to the activity that handles deep links for your app. The intent filter should catch deep links of your domain. If your messages do not contain a deep link, this configuration is not necessary. In AndroidManifest.xml:

  <action android:name="android.intent.action.VIEW"/>
  <category android:name="android.intent.category.DEFAULT"/>
  <category android:name="android.intent.category.BROWSABLE"/>
  <data android:host="" android:scheme="http"/>
  <data android:host="" android:scheme="https"/>

It is also possible to specify a wildcard to make the intent filter more flexible. For example:

  <action android:name="android.intent.action.VIEW"/>
  <category android:name="android.intent.category.DEFAULT"/>
  <category android:name="android.intent.category.BROWSABLE"/>
  <data android:host="*" android:scheme="http"/>
  <data android:host="*" android:scheme="https"/>

When users tap a notification containing a link to the scheme and host you specify, your app will start the activity with this intent filter to handle the link.

Next steps

After setting up the client app, you are ready to send downstream and topic messages with the Firebase. To learn more, see this functionality demonstrated in the quickstart sample which you can download, run, and review.

To add other, more advanced behavior to your app see the guides for sending messages from an app server:

Keep in mind that you'll need a server implementation to make use of these features.