Developing an SDK - How to send Firebase events to SDK firebase account, not the app one?

Question

Firebase is great, it helps in so many ways, and well-integrated with crashalytics, Google Analytics, Google Tag Manager, you name it.

We are building a mobile SDK, however, it seems that you can only link to Firebase on the app level (you can't initialise your own SDK to send to a different account than App's Firebase account).

Is there a workaround to allow me as an SDK developer to collect events, crash reports,.... to a Firebase account related to the SDK alone, regardless to the app that is using the SDK?

Many thanks

Answer 1

You can initialize more than one instance of the SDK at once. However, you should make consumers of your SDK aware that it is doing so and they should have a clear way to opt-out.

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When an application is launched, the FirebaseInitProvider will handle initialization of the default application instance. This default app instance has a name of "[DEFAULT]".

If you wanted to have a second user logged in, make use of a separate project, make use of a secondary database, and so on - you can just initialize another application instance. Importantly (taken from the docs), any FirebaseApp initialization must occur only in the main process of the app. Use of Firebase in processes other than the main process is not supported and will likely cause problems related to resource contention.

This is done using FirebaseApp.initializeApp() like so:

FirebaseApp nameApp = FirebaseApp.initializeApp(context, config, "name");

To replicate the default instance so you can have more than one user logged in, you can use:

FirebaseApp defaultApp = FirebaseApp.getInstance();

FirebaseApp secondaryApp = FirebaseApp.initializeApp(
    defaultApp.getApplicationContext(),
    defaultApp.getOptions(),
    "secondary"
);

To use a separate instance entirely, you load your configuration into a FirebaseOptions object using:

FirebaseOptions sdkAppOptions = new FirebaseOptions.Builder()
    .setApiKey(sdkApiKey)
    .setApplicationId(sdkAppId)
    .setDatabaseUrl(sdkDatabaseUrl)
    .setGcmSenderId(sdkGcmSenderId)
    .setProjectId(sdkProjectId)
    .setStorageBucket(sdkStorageBucket)
    .build();

FirebaseApp sdkApp = FirebaseApp.initializeApp(
    sdkContext,
    sdkAppOptions,
    "com-example-mysdkproject" // <- use namespace as best practice
);

Once you have an instance of FirebaseApp, you can then pass it through to other the other services using:

FirebaseAuth sdkAuth = FirebaseAuth.getInstance(sdkApp);
// or
FirebaseApp sdkApp = FirebaseApp.getInstance("com-example-mysdkproject");
FirebaseAuth sdkAuth = FirebaseAuth.getInstance();