This page describes how to use more than one Firebase project in your app.
Many apps need only a single Firebase project and the default set up
described in the Get Started guides. Examples of when it can be useful
to use multiple Firebase projects include:
Setting up your development environment to use different Firebase projects
based on build type or target.
Accessing the content from multiple Firebase projects in your app.
Support different environments
One common use case is to support separate Firebase projects for your development
and production environments.
The Web and Admin SDKs are configured by directly
passing values to their initialization functions. For these SDK, you can use a
runtime check to select development or production configuration variables.
Android and Apple platforms (and their Unity and C++ wrappers) normally load
configuration from a configuration file: GoogleService-Info.plist on Apple
platform and google-services.json on Android. These files are read into an
options object (FIROption or FirebaseOptions) that is referenced by the
Firebase application object (FIRApp or FirebaseApp).
For these platforms, switching between environments is usually implemented as a
build time decision, through use of different configuration files for each
environment.
Support multiple environments in your Apple application
By default, FirebaseApp.configure() will load the GoogleService-Info.plist file
bundled with the application. If your development and production environments
are configured as separate targets in Xcode, you can:
Download both GoogleService-Info.plist files
Store the two files in different directories
Add both to your Xcode project
Associate the different files with the different targets using the Target
Membership panel:
If the builds are part of a single target, the best option is to give both
configuration files unique names (e.g. GoogleService-Info-Free.plist and
GoogleService-Info-Paid.plist). Then choose at runtime which plist to load.
This is shown in the following example:
Support multiple environments in your Android application
In Android, the google-services.json file is processed into Android string
resources by the Google Services gradle plugin. You can see
which resources are created in the Google Services Plugin documentation on
Processing the JSON file.
You can have multiple google-services.json files for different
build variants
by placing google-services.json files in dedicated directories named for each
variant under the app module root. For example, if you have "development" and
"release" build flavors, your configuration could be organized like this:
To learn more, see the Google Services Plugin documentation on
Adding the JSON file.
These resources are then loaded by the
FirebaseInitProvider,
which runs before your application code and initializes Firebase APIs using
those values.
Because this provider is just reading resources with known names, another
option is to add the string resources directly to your app instead of using
the Google Services gradle plugin. You can do this by:
Removing the google-services plugin from your root build.gradle
Deleting the google-services.json from your project
Adding the string resources directly
Deleting apply plugin: 'com.google.gms.google-services' from your app build.gradle
Use multiple projects in your application
Sometimes you need to access different projects using the same APIs - for
example, accessing multiple database instances. In most cases there is a central
Firebase application object that manages the configuration for all the Firebase
APIs. This object is initialized as part of your normal setup. However, when you
want to access multiple projects from a single application, you’ll need a
distinct Firebase application object to reference each one individually. It’s
up to you to initialize these other instances.
In both cases, you need to first create a Firebase options object to hold the
configuration data for the Firebase application. Full documentation
for the options can be found in the API reference documentation for the
following classes:
The use of these classes to support multiple projects in an application is shown
in the following examples:
Swift
// Configure with manual options. Note that projectID and apiKey, though not// required by the initializer, are mandatory.letsecondaryOptions=FirebaseOptions(googleAppID:"1:27992087142:ios:2a4732a34787067a",gcmSenderID:"27992087142")secondaryOptions.apiKey="AIzaSyBicqfAZPvMgC7NZkjayUEsrepxuXzZDsk"secondaryOptions.projectID="projectid-12345"// The other options are not mandatory, but may be required// for specific Firebase products.secondaryOptions.bundleID="com.google.firebase.devrel.FiroptionConfiguration"secondaryOptions.clientID="27992087142-ola6qe637ulk8780vl8mo5vogegkm23n.apps.googleusercontent.com"secondaryOptions.databaseURL="https://myproject.firebaseio.com"secondaryOptions.storageBucket="myproject.appspot.com"secondaryOptions.deepLinkURLScheme="myapp://"secondaryOptions.storageBucket="projectid-12345.appspot.com"secondaryOptions.appGroupID=nil.swift
Kotlin
// Manually configure Firebase Options. The following fields are REQUIRED:// - Project ID// - App ID// - API Keyvaloptions=FirebaseOptions.Builder().setProjectId("my-firebase-project").setApplicationId("1:27992087142:android:ce3b6448250083d1").setApiKey("AIzaSyADUe90ULnQDuGShD9W23RDP0xmeDc6Mvw")// .setDatabaseUrl(...)// .setStorageBucket(...).build()
Java
// Manually configure Firebase Options. The following fields are REQUIRED:// - Project ID// - App ID// - API KeyFirebaseOptionsoptions=newFirebaseOptions.Builder().setProjectId("my-firebase-project").setApplicationId("1:27992087142:android:ce3b6448250083d1").setApiKey("AIzaSyADUe90ULnQDuGShD9W23RDP0xmeDc6Mvw")// setDatabaseURL(...)// setStorageBucket(...).build();
Web
// The following fields are REQUIRED:// - Project ID// - App ID// - API KeyconstsecondaryAppConfig={projectId:"<PROJECT_ID>",appId:"<APP_ID>",apiKey:"<API_KEY>",// databaseURL: "...",// storageBucket: "...",};
C++
firebase::AppOptionssecondary_app_options;// API key, app ID, and project ID are always required.secondary_app_options.set_api_key("<API_KEY>");secondary_app_options.set_app_id("<GOOGLE_APP_ID>");secondary_app_options.set_project_id("<PROJECT_ID>");// The following options are specific to individual Firebase products// and may not always be required.secondary_app_options.set_database_url("<DATABASE_URL>");secondary_app_options.set_messaging_sender_id("<SENDER_ID>");secondary_app_options.set_storage_bucket("<STORAGE_BUCKET>");
constsecondaryServiceAccount=require('./path/to/serviceAccountKey.json');// All required options are specified by the service account,// add service-specific configuration like databaseURL as needed.constsecondaryAppConfig={credential:cert(secondaryServiceAccount),// databaseURL: 'https://<DATABASE_NAME>.firebaseio.com'};
After you have initialized this options object, you can use it to configure an
additional Firebase application instance. Note that in all the examples shown
below we use the string secondary. This name is used to retrieve the
application instance, and to distinguish it from other instances, including the
default instance (named [DEFAULT]). You should pick a string appropriate to
the intended use of the other Firebase project.
The following snippets demonstrate connecting to an alternative Realtime Database
(the APIs for other Firebase features follow the same pattern).
Swift
// Configure an alternative FIRApp.FirebaseApp.configure(name:"secondary",options:secondaryOptions)// Retrieve a previous created named app.guardletsecondary=FirebaseApp.app(name:"secondary")else{fatalError("Could not retrieve secondary app")}// Retrieve a Real Time Database client configured against a specific app.letsecondaryDb=Database.database(app:secondary)
Kotlin
// Initialize secondary FirebaseApp.Firebase.initialize(context=this,options,"secondary")// Retrieve secondary FirebaseApp.valsecondary=Firebase.app("secondary")// Get the database for the other app.valsecondaryDatabase=Firebase.database(secondary)
Java
// Initialize with secondary appFirebaseApp.initializeApp(this/* Context */,options,"secondary");// Retrieve secondary FirebaseAppFirebaseAppsecondary=FirebaseApp.getInstance("secondary");
Web
// Initialize another app with a different configconstsecondaryApp=firebase.initializeApp(secondaryAppConfig,"secondary");// Access services, such as the Realtime Database// secondaryApp.database();
// Initialize another app with a different configconstsecondary=initializeApp(secondaryAppConfig,'secondary');// Access services, such as the Realtime Database// const secondaryDatabase = secondary.database();
Java
// Initialize another app with a different configFirebaseAppsecondaryApp=FirebaseApp.initializeApp(secondaryAppConfig,"secondary");// Retrieve the database.FirebaseDatabasesecondaryDatabase=FirebaseDatabase.getInstance(secondaryApp);
Ensure reliable reporting for Analytics
Google Analytics collects events very early in the app start up flow, in
some occasions before the primary Firebase app instance has been configured. In
these cases, Firebase refers to the Android resource or
GoogleService-Info.plist on Apple platforms to look up the correct Google app
ID to store events. For this reason, we recommend using the default
configuration methods wherever possible.
If runtime configuration is required, please note the following caveats:
If you're using AdMob and request ads at startup as recommended, you may
miss some Analytics data to related to mobile ads when not using the resource
based configuration approach.
Only ever supply a single Google app ID in each distributed variant of your app.
For example, if you ship version 1 of your app with a certain GOOGLE_APP_ID in
the configuration then upload version 2 with a different ID, it may cause
analytics data to be dropped.
On Apple platforms, do not add GoogleService-Info.plist to your project if
you are supplying different configuration at run time, as this can result in an
apparent change of GOOGLE_APP_ID and result in lost Analytics.
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