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initializeApp() function

Creates and initializes a FirebaseApp instance.

See Add Firebase to your app and Initialize multiple projects for detailed documentation.

Signature:

export declare function initializeApp(options: FirebaseOptions, name?: string): FirebaseApp;

Parameters

Parameter	Type	Description
options	FirebaseOptions	Options to configure the app's services.
name	string	Optional name of the app to initialize. If no name is provided, the default is "[DEFAULT]".

Returns:

FirebaseApp

The initialized app.

Example 1

// Initialize default app
// Retrieve your own options values by adding a web app on
// https://console.firebase.google.com
initializeApp({
  apiKey: "AIza....",                             // Auth / General Use
  authDomain: "YOUR_APP.firebaseapp.com",         // Auth with popup/redirect
  databaseURL: "https://YOUR_APP.firebaseio.com", // Realtime Database
  storageBucket: "YOUR_APP.appspot.com",          // Storage
  messagingSenderId: "123456789"                  // Cloud Messaging
});

Example 2

// Initialize another app
const otherApp = initializeApp({
  databaseURL: "https://<OTHER_DATABASE_NAME>.firebaseio.com",
  storageBucket: "<OTHER_STORAGE_BUCKET>.appspot.com"
}, "otherApp");