Send your First Message to a Backgrounded App

To get started with FCM, build out the simplest use case: sending a notification message from the Notifications composer to a specific user's device when the app is in the background on the device. This page lists all the steps to achieve this, from setup to verification — it may cover steps you already completed if you have set up an iOS client app for FCM.

Add Firebase to your iOS project

This section covers tasks you may have completed if you have already enabled other Firebase features for your app. For the Notifications composer specifically, you'll need to upload your APNs certificate and register for remote notifications.

Prerequisites

Before you begin, you need a few things set up in your environment:

  • Xcode 8.0 or later
  • An Xcode project targeting iOS 8 or above
  • Swift projects must use Swift 3.0 or later
  • The bundle identifier of your app
  • CocoaPods 1.2.0 or later
  • For Cloud Messaging:
    • A physical iOS device
    • An Apple Push Notification Authentication Key for your Apple Developer account
    • In Xcode, enable Push Notifications in App > Capabilities

If you don't have an Xcode project already, you can download one of our quickstart samples if you just want to try a Firebase feature. If you're using a quickstart, remember to get the bundle identifier from the project settings, you'll need it for the next step.

Add Firebase to your app

It's time to add Firebase to your app. To do this you'll need a Firebase project and a Firebase configuration file for your app.

  1. Create a Firebase project in the Firebase console, if you don't already have one. If you already have an existing Google project associated with your mobile app, click Import Google Project. Otherwise, click Add project.
  2. Click Add Firebase to your iOS app and follow the setup steps. If you're importing an existing Google project, this may happen automatically and you can just download the config file.
  3. When prompted, enter your app's bundle ID. It's important to enter the bundle ID your app is using; this can only be set when you add an app to your Firebase project.
  4. At the end, you'll download a GoogleService-Info.plist file. You can download this file again at any time.
  5. If you haven't done so already, add this file to your Xcode project root using the Add Files utility in Xcode (From the File menu, click Add Files). Make sure the file is included in your app's build target.

Add the SDK

If you are setting up a new project, you need to install the SDK. You may have already completed this as part of creating a Firebase project.

We recommend using CocoaPods to install the libraries. You can install Cocoapods by following the installation instructions. If you'd rather not use CocoaPods, you can integrate the SDK frameworks directly by following the instructions below.

If you are planning to download and run one of the quickstart samples, the Xcode project and Podfile are already present, but you'll still need to install the pods and download the GoogleService-Info.plist file. If you would like to integrate the Firebase libraries into one of your own projects, you will need to add the pods for the libraries that you want to use.

  1. If you don't have an Xcode project yet, create one now.

  2. Create a Podfile if you don't have one:

    $ cd your-project directory
    $ pod init
    
  3. Add the pods that you want to install. You can include a Pod in your Podfile like this:

    pod 'Firebase/Core'
    pod 'Firebase/Messaging'
    

    This will add the prerequisite libraries needed to get Firebase up and running in your iOS app, along with Google Analytics for Firebase. A list of currently available pods and subspecs is provided below. These are linked in feature specific setup guides as well.

  4. Install the pods and open the .xcworkspace file to see the project in Xcode.

    $ pod install
    $ open your-project.xcworkspace
    
  5. Download a GoogleService-Info.plist file from Firebase console and include it in your app.

Upload your APNs authentication key

Upload your APNs authentication key to Firebase. If you don't already have an APNs authentication key, see Configuring APNs with FCM.

  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 Certificates, Identifiers & Profiles in the Apple Developer Member Center) and click Upload.

Initialize Firebase in your app

You'll need to add Firebase initialization code to your application. Import the Firebase module and configure a shared instance as shown:

  1. Import the Firebase module in your UIApplicationDelegate subclass:

    Swift

    import Firebase
    

    Objective-C

    @import Firebase;
    
  2. Configure a FirebaseApp shared instance, typically in your application's application:didFinishLaunchingWithOptions: method:

    Swift

    // Use Firebase library to configure APIs
    FirebaseApp.configure()
    

    Objective-C

    // Use Firebase library to configure APIs
    [FIRApp configure];
    

Register for remote notifications

Either at startup, or at the desired point in your application flow, register your app for remote notifications. Call registerForRemoteNotifications as shown:

Swift

if #available(iOS 10.0, *) {
  // For iOS 10 display notification (sent via APNS)
  UNUserNotificationCenter.current().delegate = self

  let authOptions: UNAuthorizationOptions = [.alert, .badge, .sound]
  UNUserNotificationCenter.current().requestAuthorization(
    options: authOptions,
    completionHandler: {_, _ in })
} else {
  let settings: UIUserNotificationSettings =
  UIUserNotificationSettings(types: [.alert, .badge, .sound], categories: nil)
  application.registerUserNotificationSettings(settings)
}

application.registerForRemoteNotifications()

Objective-C

if (floor(NSFoundationVersionNumber) <= NSFoundationVersionNumber_iOS_9_x_Max) {
  UIUserNotificationType allNotificationTypes =
  (UIUserNotificationTypeSound | UIUserNotificationTypeAlert | UIUserNotificationTypeBadge);
  UIUserNotificationSettings *settings =
  [UIUserNotificationSettings settingsForTypes:allNotificationTypes categories:nil];
  [application registerUserNotificationSettings:settings];
} else {
  // iOS 10 or later
  #if defined(__IPHONE_10_0) && __IPHONE_OS_VERSION_MAX_ALLOWED >= __IPHONE_10_0
  // For iOS 10 display notification (sent via APNS)
  [UNUserNotificationCenter currentNotificationCenter].delegate = self;
  UNAuthorizationOptions authOptions =
      UNAuthorizationOptionAlert
      | UNAuthorizationOptionSound
      | UNAuthorizationOptionBadge;
  [[UNUserNotificationCenter currentNotificationCenter] requestAuthorizationWithOptions:authOptions completionHandler:^(BOOL granted, NSError * _Nullable error) {
      }];
  #endif
}

[application registerForRemoteNotifications];

Access the registration token

To send a message to a specific device, you need to know that device's registration token. Because you'll need to enter the token in a field in the Notifications composer to complete this tutorial, make sure to copy the token or securely store it after you retrieve it.

By default, the FCM SDK generates a registration token for the client app instance on initial startup of your app. Similar to the APNs device token, this token allows you to target notification messages to this particular instance of the app.

In the same way that iOS typically delivers an APNs device token on app start, FCM provides a registration token via the messaging:didReceiveRegistrationToken callback of the FIRMessaging delegate on each app startup. During the first app start, and in all situations where the registration token is changed, the FCM SDK retrieves the token. In both cases, the FCM SDK calls messaging:didReceiveRegistrationToken: found in the FIRMessageDelegate protocol.

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.

Set the FIRMessaging delegate

To receive registration tokens on app start, implement the FIRMessagingDelegate protocol in a class and provide it to FIRMessaging’s delegate property after calling [FIRApp configure]. For example, if your application delegate conforms to the FIRMessagingDelegate protocol, you can set the delegate on application:didFinishLaunchingWithOptions: to itself.

Swift

Messaging.messaging().delegate = self

Objective-C

[FIRMessaging messaging].delegate = self;

Receive the current registration token

Registration tokens are delivered via the FIRMessagingDelegate method messaging:didReceiveRegistrationToken:. This method is called generally once per app start with an FCM token. When this method is called, it is the ideal time to:

  • If the registration token is new, send it to your application server (it's recommended to implement server logic to determine whether the token is new).
  • Subscribe the registration token to topics. This is required only for new subscriptions or for situations where the user has re-installed the app.

Swift

let token = Messaging.messaging().fcmToken
print("FCM token: \(token ?? "")")

Objective-C

NSString *fcmToken = [FIRMessaging messaging].FCMToken;
NSLog(@"FCM registration token: %@", fcmToken);
After this delegate method is called, the registration token is available via the `FCMToken` property of `FIRMessaging`. Prior to this delegate method call, the property may be nil.

Monitor token generation

To be notified whenever the token is updated, supply a delegate conforming to the FIRMessagingDelegate protocol. The following example registers the delegate and adds the proper delegate method:

Swift

func messaging(_ messaging: Messaging, didReceiveRegistrationToken fcmToken: String) {
  print("Firebase registration token: \(fcmToken)")

  // TODO: If necessary send token to application server.
  // Note: This callback is fired at each app startup and whenever a new token is generated.
}

Objective-C

- (void)messaging:(FIRMessaging *)messaging didReceiveRegistrationToken:(NSString *)fcmToken {
    NSLog(@"FCM registration token: %@", fcmToken);

    // TODO: If necessary send token to application server.
    // Note: This callback is fired at each app startup and whenever a new token is generated.
}

Alternatively, you can listen for an NSNotification named kFIRMessagingRegistrationTokenRefreshNotification rather than supplying a delegate method. The [FIRMessaging messaging]. FCMToken property always has the current token value.

Send a notification message

  1. Install and run the app on the target device. You'll need to accept the request for permission to receive remote notifications.

  2. Make sure the app is in the background on the device.

  3. Open the Notifications composer and select New Message.

  4. Enter the message text.

  5. Select Single Device for the message target.

  6. In the field labeled FCM Registration Token, enter the registration token you obtained in a previous section of this guide.

After you click Send Message, targeted client devices that have the app in the background receive the notification in the notification center.

Next steps

To go beyond notification messages and add other, more advanced behavior to your app, see:

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