Migrate to Firebase Installation IDs

If you send push notifications through FCM, register Firebase Installation IDs (FIDs) with Customer.io instead of FCM registration tokens. FID mode is optional, and your existing token-based integration keeps working until you choose to migrate.

If you send push notifications through FCM, Firebase can register devices with Firebase Installation IDs (FIDs) ↗ instead of FCM registration tokens. Starting in version 3.12.0 of customerio-expo-plugin, you can turn on FID registration with a plugin option, and the Customer.io SDK registers the FID. Until you do, the SDK keeps registering FCM tokens.

When someone opens a version of your app with FID registration turned on, the SDK replaces the device’s FCM token with the FID on their profile. You don’t need to change anything in Customer.io. To learn how FIDs differ from FCM tokens and how Customer.io sends to each, see Device IDs.

Turn on FID mode

1. Update customerio-expo-plugin to 3.12.0 or later and customerio-reactnative to 6.14.0 or later. Use firebase-messaging 25.1.2 or later on Android and FirebaseMessaging 12.19.0 or later on iOS. On iOS, React Native Firebase 27 uses Firebase iOS 13, which CioFirebaseWrapper doesn’t support.
2. Add the firebaseInstallationId option at the top level of your plugin config in app.json or app.config.js. The plugin turns on Firebase’s FID setting on Android, and on iOS when you use the fcm provider.
   JSON

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   {
     "plugins": [
       [
         "customerio-expo-plugin",
         {
           "ios": { "pushNotification": { "provider": "fcm" } },
           "firebaseInstallationId": {
             "enabled": true
           }
         }
       ]
     ]
   }

3. Run npx expo prebuild.
4. If your app calls CustomerIO.registerDeviceToken(), pass the FID instead of a token from another package. You can get it with getId() from React Native Firebase’s Installations module. Firebase doesn’t return an FCM token in FID mode. On a fresh iOS install, if you set ios.pushNotification.autoFetchDeviceToken to false and turned off FCM auto-initialization (FirebaseMessagingAutoInitEnabled), neither the SDK nor Firebase registers the FID with FCM. Call Messaging.messaging().register(completion:) in native code before you read the FID.

To go back to FCM tokens, set enabled to false and run npx expo prebuild again.