App Management

/**
 * Initializes a Firebase app with the provided options and name
 * @param options - Options to configure the services used in the app
 * @param name - The optional name of the app to initialize ('[DEFAULT]' if omitted)
 * @returns Promise resolving to the initialized Firebase app
 */
function initializeApp(options: FirebaseAppOptions, name?: string): Promise<FirebaseApp>;

/**
 * Initializes a Firebase app with the provided options and config
 * @param options - Options to configure the services used in the app
 * @param config - The optional config for your firebase app
 * @returns Promise resolving to the initialized Firebase app
 */
function initializeApp(options: FirebaseAppOptions, config?: FirebaseAppConfig): Promise<FirebaseApp>;

import { initializeApp } from '@react-native-firebase/app';

// Initialize default app
const defaultApp = await initializeApp({
  apiKey: 'AIzaSyDdVgKwhZl0sTTTLZ7iTmt1r3N2cJLnaDk',
  authDomain: 'my-project.firebaseapp.com',
  projectId: 'my-project',
  appId: '1:12345678901:android:abc123def456'
});

// Initialize named app
const secondaryApp = await initializeApp({
  apiKey: 'different-api-key',
  projectId: 'secondary-project',
  appId: 'secondary-app-id'
}, 'secondary');

// Initialize with config
const configuredApp = await initializeApp({
  apiKey: 'api-key',
  projectId: 'project-id',
  appId: 'app-id'
}, {
  name: 'configured',
  automaticDataCollectionEnabled: false,
  automaticResourceManagement: true
});

/**
 * Retrieves an instance of a Firebase app
 * @param name - The optional name of the app to return ('[DEFAULT]' if omitted)
 * @returns The requested Firebase app instance
 */
function getApp(name?: string): FirebaseApp;

import { getApp } from '@react-native-firebase/app';

// Get default app
const defaultApp = getApp();
console.log(defaultApp.name); // '[DEFAULT]'

// Get named app
const secondaryApp = getApp('secondary');
console.log(secondaryApp.name); // 'secondary'

/**
 * Gets the list of all initialized apps
 * @returns An array of all initialized Firebase apps
 */
function getApps(): FirebaseApp[];

import { getApps } from '@react-native-firebase/app';

// Get all initialized apps
const allApps = getApps();
console.log(`Total apps: ${allApps.length}`);

allApps.forEach(app => {
  console.log(`App: ${app.name}, Project: ${app.options.projectId}`);
});

/**
 * Renders this app unusable and frees the resources of all associated services
 * @param app - The app to delete
 * @returns Promise that resolves when the app is deleted
 */
function deleteApp(app: FirebaseApp): Promise<void>;

import { deleteApp, getApp, SDK_VERSION } from '@react-native-firebase/app';

// Delete a specific app
const myApp = getApp('secondary');
await deleteApp(myApp);

console.log('App deleted successfully');

// Get SDK version
console.log('Firebase SDK Version:', SDK_VERSION);

/**
 * Registers a library's name and version for platform logging purposes
 * @param libraryKeyOrName - Library name or key
 * @param version - Library version  
 * @param variant - Library variant (optional)
 * @returns Promise that resolves when registration is complete
 * @throws Error on React Native platforms (only supported on Web)
 */
function registerVersion(libraryKeyOrName: string, version: string, variant?: string): Promise<void>;

import { registerVersion } from '@react-native-firebase/app';

try {
  // This will throw an error on React Native
  await registerVersion('my-library', '1.0.0', 'react-native');
} catch (error) {
  console.log('registerVersion is only supported on Web');
}

/**
 * The current SDK version string
 */
const SDK_VERSION: string;

import { SDK_VERSION } from '@react-native-firebase/app';

console.log('React Native Firebase version:', SDK_VERSION);

// Useful for debugging or logging
console.log(`App initialized with RNFirebase ${SDK_VERSION}`);

import firebase from '@react-native-firebase/app';

// Access default app
const app = firebase.app();

// Initialize new app (traditional style)
const newApp = await firebase.initializeApp(options, name);

// Get app (traditional style)  
const myApp = firebase.app('myAppName');

// Get all apps
const apps = firebase.apps;

import { getApp } from '@react-native-firebase/app';

try {
  const app = getApp('nonexistent');
} catch (error) {
  console.log(error.code); // Firebase error code
  console.log(error.message); // Error message
}

import { getApp } from '@react-native-firebase/app';

const app = getApp();

// Read-only properties
console.log(app.name); // App name
console.log(app.options); // App configuration options

// Settable properties  
app.automaticDataCollectionEnabled = false;

// Methods
await app.delete(); // Delete the app
const utils = app.utils(); // Get utils module