react-native-firebase/docs/core/app.md

Apps

?> For the default app see: Default App

?> For initializing additional apps natively and also via js code over the RN bridge see: Dynamically Initializing Apps

Reading App Options

!> <app>.options.clientId is not available on the Android Firebase SDK so will return null for Android, see the issue: firebase/firebase-ios-sdk#140 (comment)

Just like the Firebase web sdk you can view options used to initialize an app instance in the same way, for example:

import firebase from 'react-native-firebase';

const defaultApp = firebase.app();

// get the default app name/options that the app initialized with
console.log("name", defaultApp.name);
console.log("apiKey", defaultApp.options.apiKey);
console.log("applicationId", defaultApp.options.applicationId);
console.log("databaseUrl", defaultApp.options.databaseUrl);
console.log("messagingSenderId", defaultApp.options.messagingSenderId);
console.log("projectId", defaultApp.options.projectId);
console.log("storageBucket", defaultApp.options.projectId);