### Setup Firestore Emulator

Source: https://github.com/firebase/firebase-js-sdk/blob/main/packages/firestore/CONTRIBUTING.md

Installs the Firestore emulator. This command downloads and sets up the necessary components for the emulator.

```bash
firebase setup:emulators:firestore
```

--------------------------------

### Initialize AI with Default Settings

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/ai.md

Example of getting the default AI instance without specific options.

```javascript
const ai = getAI(app);
```

--------------------------------

### Install SDK Dependencies

Source: https://github.com/firebase/firebase-js-sdk/blob/main/README.md

Run this command in the root of the SDK directory to install all necessary development dependencies.

```bash
yarn
```

--------------------------------

### Start Firestore Emulator

Source: https://github.com/firebase/firebase-js-sdk/blob/main/packages/firestore/CONTRIBUTING.md

Starts the Firestore emulator. Use this command to run tests against a local Firestore instance.

```bash
firebase emulators:start --only firestore
```

--------------------------------

### Install Firebase CLI

Source: https://github.com/firebase/firebase-js-sdk/blob/main/packages/firestore/CONTRIBUTING.md

Installs the Firebase CLI globally. This is a prerequisite for using Firebase emulators.

```bash
npm install -g firebase-tools
```

--------------------------------

### Start Chat Session

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/ai.generativemodel.md

Gets a new ChatSession instance for multi-turn conversations. Pass StartChatParams for initial configuration.

```typescript
startChat(startChatParams?: StartChatParams): ChatSession;
```

--------------------------------

### Initialize Firebase App Example (JavaScript)

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/app.md

Demonstrates how to initialize the default Firebase app using provided configuration options. This example shows the structure of the options object, including essential keys like apiKey, authDomain, and databaseURL. Replace placeholder values with your actual Firebase project credentials.

```javascript
// 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"
});
```

--------------------------------

### Build the SDK

Source: https://github.com/firebase/firebase-js-sdk/blob/main/README.md

Execute this command in the root of the SDK directory after installing dependencies to build the entire SDK.

```bash
yarn build
```

--------------------------------

### onConfigUpdate

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/remote-config.md

Starts listening for real-time config updates and automatically fetches updates.

```APIDOC
## onConfigUpdate(remoteConfig, observer)

### Description
Starts listening for real-time config updates from the Remote Config backend and automatically fetches updates from the Remote Config backend when they are available.

### Parameters
#### Path Parameters
- **remoteConfig** (object) - Required - The Remote Config instance.
- **observer** (object) - Required - An observer object with `onConfigUpdated` and `onError` methods.

### Returns
- (function) - A function to unsubscribe from the updates.
```

--------------------------------

### LiveGenerativeModel.connect()

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/ai.livegenerativemodel.md

Starts a LiveSession for real-time interaction.

```APIDOC
## LiveGenerativeModel.connect()

### Description
Starts a [LiveSession](./ai.livesession.md#livesession_class).

### Method
```typescript
connect(sessionResumption?: SessionResumptionConfig): Promise<LiveSession>;
```

### Parameters
#### Query Parameters
- **sessionResumption** (SessionResumptionConfig) - Optional - Configuration for resuming a session.

### Response
#### Success Response (200)
- **LiveSession** - A [LiveSession](./ai.livesession.md#livesession_class) object.

#### Exceptions
- If the connection failed to be established with the server.
```

--------------------------------

### Add Field Values Example

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/firestore_pipelines.md

Example demonstrating how to add the values of two fields using the `add` function.

```typescript
// Add the value of the 'quantity' field and the 'reserve' field.
add("quantity", field("reserve"));
```

--------------------------------

### Install and Initialize Firebase in Node.js (CommonJS)

Source: https://github.com/firebase/firebase-js-sdk/blob/main/packages/firebase/README.md

This snippet shows how to install the Firebase SDK using npm and initialize it in a Node.js environment using CommonJS modules. It covers installing the 'firebase' package and importing necessary functions for app initialization and Firestore.

```bash
$ npm init
$ npm install --save firebase
```

```javascript
const { initializeApp } = require('firebase/app');
const { getFirestore, collection, getDocs } = require('firebase/firestore');
// ...

// TODO: Replace the following with your app's Firebase project configuration
const firebaseConfig = {
  //...
};

const app = initializeApp(firebaseConfig);
const db = getFirestore(app);

// Example usage (assuming you have a 'cities' collection)
async function getCities(db) {
  const citiesCol = collection(db, 'cities');
  const citySnapshot = await getDocs(citiesCol);
  const cityList = citySnapshot.docs.map(doc => doc.data());
  return cityList;
}

getCities(db).then(cities => console.log(cities));
```

--------------------------------

### Execute pipeline and iterate results

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/firestore_pipelines.pipelinesnapshot.md

Example showing how to execute a pipeline and iterate over the resulting documents.

```typescript
const snapshot: PipelineSnapshot = await firestore
  .pipeline()
  .collection('myCollection')
  .where(field('value').greaterThan(10))
  .execute();

snapshot.results.forEach(doc => {
  console.log(doc.id, '=>', doc.data());
});
```

--------------------------------

### Example: Filtering Books by Rating and Genre

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/firestore_pipelines.pipeline.md

This example demonstrates how to use the where() method with logical operators (and) and field comparators (greaterThan, equal) to filter books by rating and genre.

```typescript
firestore.pipeline().collection("books")
.where(
and(
greaterThan(field("rating"), 4.0),   // Filter for ratings greater than 4.0
field("genre").equal("Science Fiction") // Equivalent to equal("genre", "Science Fiction")
)
);
```

--------------------------------

### startAt(snapshot)

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/firestore_lite.md

Creates a QueryStartAtConstraint that modifies the result set to start at the provided document (inclusive). The starting position is relative to the order of the query. The document must contain all of the fields provided in the orderBy of this query.

```APIDOC
## startAt(snapshot)

### Description
Creates a `QueryStartAtConstraint` that modifies the result set to start at the provided document (inclusive). The starting position is relative to the order of the query. The document must contain all of the fields provided in the `orderBy` of this query.

### Signature
```typescript
export declare function startAt<AppModelType, DbModelType extends DocumentData>(snapshot: DocumentSnapshot<AppModelType, DbModelType>): QueryStartAtConstraint;
```

### Parameters
#### Path Parameters
- **snapshot** (DocumentSnapshot<AppModelType, DbModelType>) - Required - The snapshot of the document to start at.

### Returns
- **QueryStartAtConstraint** - A `QueryStartAtConstraint` to pass to `query()`.
```

--------------------------------

### GenerativeModel.startChat()

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/ai.generativemodel.md

Gets a new ChatSession instance for multi-turn conversations.

```APIDOC
## GenerativeModel.startChat()

### Description
Gets a new [ChatSession](./ai.chatsession.md#chatsession_class) instance which can be used for multi-turn chats.

### Method Signature
```typescript
startChat(startChatParams?: StartChatParams): ChatSession;
```

### Parameters
#### startChatParams
- **startChatParams** ([StartChatParams](./ai.startchatparams.md#startchatparams_interface)) - Description not provided.

### Returns
[ChatSession](./ai.chatsession.md#chatsession_class)
```

--------------------------------

### linkWithPopup Usage Example

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/auth.md

Demonstrates linking a Facebook provider to an existing user session via a pop-up.

```javascript
// Sign in using some other provider.
const result = await signInWithEmailAndPassword(auth, email, password);
// Link using a popup.
const provider = new FacebookAuthProvider();
await linkWithPopup(result.user, provider);
```

--------------------------------

### Get Firebase Installation ID (TypeScript)

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/installations.md

Creates a Firebase Installation if one does not exist for the app and returns the Installation ID. This asynchronous function returns a Promise that resolves with the Installation ID string. It requires an Installations instance.

```typescript
import { Installations, getId } from "firebase/installations";

// Assuming 'installations' is an Installations instance
getId(installations).then((installationId) => {
  console.log("Firebase Installation ID: ", installationId);
}).catch((error) => {
  console.error("Error getting Firebase Installation ID: ", error);
});

```

--------------------------------

### Firebase Installations SDK - Core Functions (TypeScript)

Source: https://github.com/firebase/firebase-js-sdk/blob/main/common/api-review/installations.api.md

Provides core functions for interacting with Firebase Installations, including getting and deleting installations, and retrieving installation tokens. It relies on the FirebaseApp type from '@firebase/app'.

```typescript
import { FirebaseApp } from '@firebase/app';

// @public
export function deleteInstallations(installations: Installations): Promise<void>;

// @public
export function getId(installations: Installations): Promise<string>;

// @public
export function getInstallations(app?: FirebaseApp): Installations;

// @public
export function getToken(installations: Installations, forceRefresh?: boolean): Promise<string>;

// @public
export type IdChangeCallbackFn = (installationId: string) => void;

// @public
export type IdChangeUnsubscribeFn = () => void;

// @public
export interface Installations {
    app: FirebaseApp;
}

// @public
export function onIdChange(installations: Installations, callback: IdChangeCallbackFn): IdChangeUnsubscribeFn;
```

--------------------------------

### Install Yarn Version 1.x

Source: https://github.com/firebase/firebase-js-sdk/blob/main/README.md

Use this command to set your Yarn version to 1.x, which is supported by the SDK.

```bash
yarn set version 1.22.11
```

--------------------------------

### Get Firebase Installations Instance (TypeScript)

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/installations.md

Retrieves an instance of the Installations interface associated with a given FirebaseApp instance. This function is part of the Firebase Installations Web SDK and requires a FirebaseApp instance as input.

```typescript
import { FirebaseApp } from "firebase/app";
import { Installations, getInstallations } from "firebase/installations";

// Assuming 'app' is an initialized FirebaseApp instance
const installations: Installations = getInstallations(app);

```

--------------------------------

### Get Firebase Installations Auth Token (TypeScript)

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/installations.md

Returns a Firebase Installations auth token that identifies the current Firebase Installation. This asynchronous function can optionally force a refresh of the token. It requires an Installations instance and an optional boolean for force refresh.

```typescript
import { Installations, getToken } from "firebase/installations";

// Assuming 'installations' is an Installations instance
getToken(installations, true).then((token) => {
  console.log("Firebase Installations Auth Token: ", token);
}).catch((error) => {
  console.error("Error getting Firebase Installations Auth Token: ", error);
});

```

--------------------------------

### Retrieve specific fields with get()

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/firestore_lite_pipelines.pipelineresult.md

Method signature and usage example for retrieving a specific field from a PipelineResult.

```typescript
get(fieldPath: string | FieldPath | Field): any;
```

```javascript
let p = firestore.pipeline().collection('col');

p.execute().then(results => {
  let field = results[0].get('a.b');
  console.log(`Retrieved field value: ${field}`);
});
```

--------------------------------

### Build and Run Firebase Auth Demo

Source: https://github.com/firebase/firebase-js-sdk/blob/main/packages/auth/demo/README.md

Commands to build dependencies and launch the local development server for the authentication demo.

```bash
cd auth/demo
yarn
yarn build:deps
yarn run demo
```

--------------------------------

### GenerativeModel.startChat Method

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/ai.generativemodel.md

Gets a new ChatSession instance for multi-turn chats. Accepts start chat parameters.

```typescript
startChat(startChatParams: StartChatParams): ChatSession;
```

--------------------------------

### Run Sample Applications

Source: https://github.com/firebase/firebase-js-sdk/blob/main/e2e/smoke-tests/README.md

Commands to start the local development server for the modular or compat sample applications. These apps demonstrate basic SDK initialization and method calls.

```bash
yarn start:modular
yarn start:compat
```

--------------------------------

### Run Firebase Auth Demo with Emulator

Source: https://github.com/firebase/firebase-js-sdk/blob/main/packages/auth/demo/README.md

Commands to initialize the Firebase emulator and run the demo application against local mocked authentication endpoints.

```bash
cd auth/demo
firebase init
yarn run demo:emulator
```

--------------------------------

### Listen for FCM Registration Events

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/messaging_sw.md

Subscribe to registration events using `onRegistered` to get the Firebase Installation ID (FID). Use this FID to update your application server. The returned unsubscribe function stops the listener.

```typescript
export declare function onRegistered(messaging: Messaging, nextOrObserver: NextFn<string> | Observer<string>): Unsubscribe;
```

--------------------------------

### Verify Prerequisites

Source: https://github.com/firebase/firebase-js-sdk/blob/main/README.md

Run these commands to verify your Node.js, Yarn, and Java installations meet the SDK's requirements.

```bash
node -v
yarn -v
java -version
```

--------------------------------

### Get Array Element by Index with arrayGet

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/firestore_pipelines.md

Creates an expression to access a specific element within an array using its index. Supports positive and negative indices for accessing from the start or end. An error occurs if the index is out of bounds.

```typescript
arrayGet(field('tags'), 1);
```

--------------------------------

### Initialize AI with Vertex AI Backend

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/ai.md

Configures and retrieves an AI instance to use the Vertex AI Gemini API.

```javascript
// Get an AI instance configured to use the Vertex AI Gemini API.
const ai = getAI(app, { backend: new VertexAIBackend() });
```

--------------------------------

### Complete Phone Authentication with ConfirmationResult

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/auth.confirmationresult.md

This example demonstrates how to use the ConfirmationResult object to complete a phone number sign-in, link, or reauthentication flow. It shows obtaining the confirmationResult and then using the confirm method with a verification code to get a UserCredential.

```javascript
const confirmationResult = await signInWithPhoneNumber(auth, phoneNumber, applicationVerifier);
// Obtain verificationCode from the user.
const userCredential = await confirmationResult.confirm(verificationCode);
```

--------------------------------

### StartTemplateChatParams

Source: https://github.com/firebase/firebase-js-sdk/blob/main/common/api-review/ai.api.md

Extends `StartChatParams` to support starting chat sessions based on a template. It includes template-specific configurations like ID, variables, and template tools.

```APIDOC
## StartTemplateChatParams

### Description
Extends `StartChatParams` to support starting chat sessions based on a template. It includes template-specific configurations like ID, variables, and template tools.

### Parameters
#### Path Parameters
None

#### Query Parameters
None

#### Request Body
- **templateId** (string) - Required - The ID of the chat template to use.
- **templateVariables** (Record<string, unknown>) - Optional - A record of variables to be used with the template.
- **tools** (TemplateTool[]) - Optional - An array of `TemplateTool` objects available for this template chat.
```

--------------------------------

### Clone and Initialize Firebase Auth Demo

Source: https://github.com/firebase/firebase-js-sdk/blob/main/packages/auth/demo/README.md

Commands to clone the repository and prepare the Firebase project configuration for the demo application.

```bash
git clone https://github.com/firebase/firebase-js-sdk.git
cd firebase-js-sdk/packages/auth/demo
firebase use --add
cp src/sample-config.js src/config.js
```

--------------------------------

### Delete Firebase Installation (TypeScript)

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/installations.md

Deletes the Firebase Installation and all associated data. This asynchronous function returns a Promise that resolves when the deletion is complete. It requires an Installations instance as input.

```typescript
import { Installations, deleteInstallations } from "firebase/installations";

// Assuming 'installations' is an Installations instance
deleteInstallations(installations).then(() => {
  console.log("Firebase Installation deleted successfully.");
}).catch((error) => {
  console.error("Error deleting Firebase Installation: ", error);
});

```

--------------------------------

### Listen for Installation ID Changes (TypeScript)

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/installations.md

Sets a callback function to be invoked when the Installation ID changes. This function returns an unsubscribe function that can be called to remove the callback. It requires an Installations instance and a callback function.

```typescript
import { Installations, onIdChange } from "firebase/installations";

// Assuming 'installations' is an Installations instance
const unsubscribe = onIdChange(installations, (newId) => {
  console.log("Installation ID changed to: ", newId);
});

// To stop listening for changes:
// unsubscribe();

```

--------------------------------

### Initialize Auth with Custom Dependencies

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/auth.md

Initialize an Auth instance with specific persistence and resolver configurations for fine-grained control.

```js
const auth = initializeAuth(app, {
  persistence: browserSessionPersistence,
  popupRedirectResolver: undefined,
});
```

```typescript
export declare function initializeAuth(app: FirebaseApp, deps?: Dependencies): Auth;
```

--------------------------------

### Installations Interface (TypeScript)

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/installations.installations.md

Defines the public interface for the Firebase Installations SDK. It includes properties like the associated FirebaseApp instance.

```typescript
export interface Installations {
  app: FirebaseApp;
}
```

--------------------------------

### Instantiate ImagenModel and generate images

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/ai.imagenmodel.md

Instantiate the ImagenModel with your AI instance and model parameters. Then, use the `generateImages` method with a text prompt to create images. Check the response for generated images or filtering information.

```javascript
const imagen = new ImagenModel(
  ai,
  {
    model: 'imagen-3.0-generate-002'
  }
);

const response = await imagen.generateImages('A photo of a cat');
if (response.images.length > 0) {
  console.log(response.images[0].bytesBase64Encoded);
}
```

--------------------------------

### initializeFirestore(app, settings, databaseId)

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/firestore_.md

Initializes a new instance of Firestore with the provided settings. This must be called before any other function, including getFirestore(). If settings are empty, it's equivalent to calling getFirestore().

```APIDOC
## initializeFirestore(app, settings, databaseId)

### Description
Initializes a new instance of [Firestore](./firestore_.firestore.md#firestore_class) with the provided settings. Can only be called before any other function, including [getFirestore()](./firestore_.md#getfirestore). If the custom settings are empty, this function is equivalent to calling [getFirestore()](./firestore_.md#getfirestore).

### Parameters
#### Path Parameters
- **app** (FirebaseApp) - The Firebase app to which the Firestore instance is associated.
- **settings** (object) - An object containing initialization settings.
- **databaseId** (string, optional) - The ID of the Firestore database instance.

### Method
N/A (SDK function)

### Endpoint
N/A (SDK function)

### Request Example
```javascript
const settings = {
  cacheSizeBytes: 1000000
};
const db = initializeFirestore(app, settings, "my-database-id");
```

### Response
#### Success Response
- **firestore** (Firestore) - The initialized Firestore instance.
```

--------------------------------

### Collect All Tags Example

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/firestore_pipelines.md

Example showing how to use `arrayAgg` to collect all tags from books into an array.

```typescript
// Collect all tags from books into an array
arrayAgg("tags").as("allTags");
```

--------------------------------

### initializeFirestore(app, settings)

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/firestore_lite.md

Initializes a new Firestore instance with custom settings. This must be called before getFirestore().

```APIDOC
## initializeFirestore(app, settings)

### Description
Initializes a new instance of Cloud Firestore with the provided settings. Can only be called before any other functions, including [getFirestore()](./firestore_.md#getfirestore).
If the custom settings are empty, this function is equivalent to calling [getFirestore()](./firestore_.md#getfirestore).

### Method
function

### Parameters
* **app** (FirebaseApp) - The Firebase app to initialize Firestore for.
* **settings** (object) - An object containing the initialization settings.
* **...** - Additional arguments (implementation-specific).
```

--------------------------------

### Get All Database Documents (Default)

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/firestore_lite_pipelines.pipelinesource.md

Retrieves all documents from the entire database. This is the default behavior for a database stage.

```typescript
database(): PipelineType;
```

--------------------------------

### Get Parent Document Reference

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/firestore_lite_pipelines.expression.md

Use this to get the parent document reference of a given document reference.

```typescript
field("__path__").parent();
```

--------------------------------

### Collect Distinct Tags Example

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/firestore_pipelines.md

Example showing how to use `arrayAggDistinct` to collect all distinct tags from books into an array.

```typescript
// Collect all distinct tags from books into an array
arrayAggDistinct("tags").as("allDistinctTags");
```

--------------------------------

### GenerativeModel.initializeDeviceModel()

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/ai.generativemodel.md

Initializes on-device models, potentially triggering a download. Must be called after user interaction.

```APIDOC
## GenerativeModel.initializeDeviceModel()

### Description
Initializes on-device models. This may trigger a download on first use. Wait for this promise to complete before calling inference methods if you want to ensure the device models are ready before any calls. Calling inference methods before the device is ready will result in a cloud fallback if `inferenceMode` is set to `PREFER_ON_DEVICE`, and an error if set to `ONLY_ON_DEVICE`.

IMPORTANT: This call must be made on or after a user has interacted with the page (for example, through a button click or key press). If it is called without a user interaction, and it requires a download, this will cause an error.

See the [Prompt API docs](https://developer.chrome.com/docs/ai/prompt-api#use_the_prompt_api) for more details on this requirement.

### Method Signature
```typescript
initializeDeviceModel(onDownloadProgress?: (progressValue: number) => void): Promise<void>;
```

### Parameters
#### onDownloadProgress
- **onDownloadProgress** ((progressValue: number) => void) - A callback called repeatedly as the download progresses that provides a `progressValue` between 0 and 1 representing how much of the download is complete. This will be ignored if `monitor` was populated in [LanguageModelCreateOptions](./ai.languagemodelcreateoptions.md#languagemodelcreateoptions_interface).

### Returns
Promise<void>
```

--------------------------------

### Initialize AI with Google AI Backend

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/ai.md

Configures and retrieves an AI instance to use the Gemini Developer API via Google AI.

```javascript
// Get an AI instance configured to use the Gemini Developer API (via Google AI).
const ai = getAI(app, { backend: new GoogleAIBackend() });
```

--------------------------------

### Automated Test Setup for Firebase Project

Source: https://github.com/firebase/firebase-js-sdk/blob/main/README.md

Run this command to configure your Firebase project for testing. It allows interactive selection of the project or explicit specification via projectId.

```bash
# Select the Firebase project via the text-based UI. This will run tools/config.js
# and deploy from config/ to your Firebase project.
$ yarn test:setup

# Specify the Firebase project via the command-line arguments.
$ yarn test:setup --projectId=<test_firebase_project_id>
```

--------------------------------

### Firebase Installations SDK - Internal Functions (TypeScript)

Source: https://github.com/firebase/firebase-js-sdk/blob/main/common/api-review/installations.api.md

Exposes internal functionalities for Firebase Installations, such as retrieving the installation ID and token with optional force refresh. This interface is marked as @internal and should not be used in production code.

```typescript
import { FirebaseApp } from '@firebase/app';

// @internal
export interface _FirebaseInstallationsInternal {
    getId(): Promise<string>;
    getToken(forceRefresh?: boolean): Promise<string>;
}
```

--------------------------------

### initializeFirestore(app, settings)

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/firestore_lite.md

Initializes a new Firestore instance with the provided settings. This must be called before any other Firestore functions. If settings are empty, it's equivalent to calling getFirestore().

```APIDOC
## initializeFirestore(app, settings)

### Description
Initializes a new instance of Cloud Firestore with the provided settings. Can only be called before any other functions, including getFirestore(). If the custom settings are empty, this function is equivalent to calling getFirestore().

### Method
initializeFirestore

### Parameters
#### Path Parameters
- **app** (FirebaseApp) - Required - The FirebaseApp with which the Firestore instance will be associated.
- **settings** (Settings) - Required - A settings object to configure the Firestore instance.

### Returns
- **Firestore** - A newly initialized `Firestore` instance.
```

--------------------------------

### Get a DocumentReference

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/firestore_lite.md

Use the `doc` function to get a reference to a specific document. Provide the Firestore instance and the document path.

```typescript
export declare function doc(firestore: Firestore, path: string, ...pathSegments: string[]): DocumentReference<DocumentData, DocumentData>;
```

--------------------------------

### Get a CollectionReference

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/firestore_lite.md

Use the `collection` function to get a reference to a specific collection. Provide the Firestore instance and the collection path.

```typescript
export declare function collection(firestore: Firestore, path: string, ...pathSegments: string[]): CollectionReference<DocumentData, DocumentData>;
```

--------------------------------

### Send Email Sign-in Link and Handle Completion

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/auth.md

Configures action settings and sends a sign-in link to the user's email, then checks for and completes the sign-in process using the email link.

```javascript
const actionCodeSettings = {
  url: 'https://www.example.com/?email=user@example.com',
  iOS: {
     bundleId: 'com.example.ios'
  },
  android: {
    packageName: 'com.example.android',
    installApp: true,
    minimumVersion: '12'
  },
  handleCodeInApp: true
};
await sendSignInLinkToEmail(auth, 'user@example.com', actionCodeSettings);
// Obtain emailLink from the user.
if(isSignInWithEmailLink(auth, emailLink)) {
  await signInWithEmailLink(auth, 'user@example.com', emailLink);
}
```

--------------------------------

### Get Remote Config Instance

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/remote-config.md

Use this function to get an instance of the Remote Config client. You can optionally provide FirebaseApp and RemoteConfigOptions.

```typescript
export declare function getRemoteConfig(app?: FirebaseApp, options?: RemoteConfigOptions): RemoteConfig;
```

--------------------------------

### Get Download Stream

Source: https://github.com/firebase/firebase-js-sdk/blob/main/common/api-review/storage.api.md

Get a ReadableStream for downloading a file. Useful for processing file data chunk by chunk.

```APIDOC
## GET /firebase/firebase-js-sdk

### Description
Retrieves a `ReadableStream` for downloading the content of a file specified by a `StorageReference`. This is particularly useful for handling large files efficiently by processing them in chunks, rather than downloading the entire file into memory at once.

### Method
GET (Implicitly via function call)

### Endpoint
N/A (Function call)

### Parameters
#### Path Parameters
None

#### Query Parameters
None

#### Request Body
None

### Request Example
```javascript
import { getStorage, ref, getStream } from "firebase/storage";
import firebaseApp from "./firebaseConfig";

const storage = getStorage(firebaseApp);
const fileRef = ref(storage, "path/to/your/file.txt");

// Optional: Specify maximum download size
const maxSizeBytes = 1024 * 1024; // 1MB

getStream(fileRef, maxSizeBytes)
  .then(async (stream) => {
    const reader = stream.getReader();
    let result = await reader.read();
    while (!result.done) {
      const chunk = result.value;
      console.log("Received chunk:", chunk);
      // Process the chunk (e.g., write to a file, display progress)
      result = await reader.read();
    }
    console.log("Download complete.");
  })
  .catch((error) => {
    console.error("Error getting download stream: ", error);
  });
```

### Response
#### Success Response (200)
- **ReadableStream** (object) - A stream object from which file data can be read.

#### Response Example
```json
{
  "//": "This is a ReadableStream object, not a JSON response. You interact with it using its reader."
}
```
```

--------------------------------

### getAll

Source: https://github.com/firebase/firebase-js-sdk/blob/main/common/api-review/remote-config.api.md

Retrieves all configuration values from the Remote Config instance.

```APIDOC
## getAll

### Description
Retrieves all configuration values from the Remote Config instance.

### Method
`getAll(remoteConfig: RemoteConfig): Record<string, Value>`

### Parameters
*   **remoteConfig** (RemoteConfig) - The RemoteConfig instance.

### Response
*   **Record<string, Value>** - An object containing all configuration key-value pairs.
```

--------------------------------

### Generate Documentation via Yarn

Source: https://github.com/firebase/firebase-js-sdk/blob/main/CONTRIBUTING.md

Commands to install project dependencies and execute the documentation generation script. This process updates the files located in the docs-devsite/ directory.

```shell
yarn
yarn docgen:all
```

--------------------------------

### PrebuiltVoiceConfig

Source: https://github.com/firebase/firebase-js-sdk/blob/main/common/api-review/ai.api.md

Configuration for selecting a pre-built voice.

```APIDOC
## Interface: PrebuiltVoiceConfig

### Description
Configuration options for specifying a pre-defined voice to be used.

### Fields

- **voiceName** (string) - Optional - The name of the pre-built voice to use.
```

--------------------------------

### Get a subcollection reference from a CollectionReference

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/firestore_lite.md

Use `collection` with a `CollectionReference` to get a reference to a subcollection. This is useful for navigating nested data structures within Firestore.

```typescript
export declare function collection<AppModelType, DbModelType extends DocumentData>(reference: CollectionReference<AppModelType, DbModelType>, path: string, ...pathSegments: string[]): CollectionReference<DocumentData, DocumentData>;
```

--------------------------------

### Get Firestore Instance

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/firestore_lite.md

Retrieves an existing Firestore instance or initializes a new one with default settings. Use this to get a reference to your Firestore database.

```typescript
export declare function getFirestore(databaseId: string): Firestore;
```

--------------------------------

### initializeApp

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/app.md

Initializes a new FirebaseApp instance with the provided configuration options.

```APIDOC
## initializeApp(options, name)

### Description
Creates and initializes a FirebaseApp instance. This is the primary entry point for using Firebase services.

### Method
FUNCTION

### Parameters
#### Request Body
- **options** (Object) - Required - Firebase configuration object containing API keys and project identifiers.
- **name** (String) - Optional - A unique name for the app instance. If omitted, the default app is initialized.

### Response
#### Success Response
- **FirebaseApp** (Object) - The initialized Firebase application instance.
```

--------------------------------

### Get top N elements from an array

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/firestore_lite_pipelines.md

Use `arrayMaximumN` to get the top N elements from an array expression. This is useful for ranking or selecting the highest values.

```typescript
// Get the top n elements from an array expression
arrayMaximumN(field("scores"), field("count"));
```

--------------------------------

### StartTemplateChatParams Interface

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/ai.starttemplatechatparams.md

Defines the configuration object for initializing a chat session with a server-side template.

```APIDOC
## StartTemplateChatParams Interface

### Description
Parameters for TemplateGenerativeModel.startChat(). This API is currently in public preview.

### Properties
- **templateId** (string) - Required - The ID of the server-side template to execute.
- **templateVariables** (Record<string, unknown>) - Optional - A key-value map of variables to populate the template with.
- **tools** (TemplateTool[]) - Optional - A list of tools available for the template chat session.

### Request Example
{
  "templateId": "my-template-id",
  "templateVariables": {
    "user_name": "John Doe"
  },
  "tools": []
}
```

--------------------------------

### activate

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/remote-config.md

Makes the last fetched configuration available to the getters.

```APIDOC
## activate(remoteConfig)

### Description
Makes the last fetched config available to the getters.

### Parameters
#### Path Parameters
- **remoteConfig** (object) - Required - The Remote Config instance.

### Returns
- (boolean) - True if the configuration was successfully activated, false otherwise.
```

--------------------------------

### timestampDiff(endFieldName, startExpression, unit)

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/firestore_pipelines.md

Creates an expression that calculates the difference between a timestamp field and a starting timestamp expression. This overload is useful when the start time is dynamic or derived.

```APIDOC
## timestampDiff(endFieldName, startExpression, unit)

### Description
Creates an expression that calculates the difference between two timestamps.

### Parameters
#### Path Parameters
- **endFieldName** (string) - Required - The name of the field representing the ending timestamp.
- **startExpression** ([Expression](./firestore_pipelines.expression.md#expression_class)) - Required - The starting timestamp for the difference calculation.
- **unit** ([TimeUnit](./firestore_pipelines.md#timeunit) | [Expression](./firestore_pipelines.expression.md#expression_class)) - Required - The unit of time for the difference (e.g., "day", "hour").

### Returns
[FunctionExpression](./firestore_pipelines.functionexpression.md#functionexpression_class)
A new `Expression` representing the difference as an integer.

### Example

```typescript
// Calculate the difference in days between 'endTime' field and a starting timestamp expression.
timestampDiff('endTime', field('startTime'), 'day')
```
```

--------------------------------

### Initialize Named Firebase App Example (JavaScript)

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/app.md

Illustrates how to initialize a named Firebase application instance. This is useful when managing multiple Firebase projects within the same application. The second argument to initializeApp specifies the name for this particular app instance.

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

--------------------------------

### Get First N Elements of Array (Number)

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/firestore_pipelines.expression.md

Use `arrayFirstN` with a number to retrieve the first `n` elements from an array field. This is useful for getting a fixed-size prefix of an array.

```typescript
field("myArray").arrayFirstN(3);
```

--------------------------------

### Run Lite SDK Browser Tests (Emulator)

Source: https://github.com/firebase/firebase-js-sdk/blob/main/packages/firestore/CONTRIBUTING.md

Executes the Lite version of the Cloud Firestore SDK tests in a browser environment (Chrome Headless) against the emulator.

```bash
yarn test:lite:browser
```

--------------------------------

### Install Firebase NPM Module

Source: https://github.com/firebase/firebase-js-sdk/blob/main/packages/firebase/README.md

Installs the Firebase NPM module using npm. This is the first step to integrate Firebase into your web or Node.js application.

```bash
$ npm init
$ npm install --save firebase
```

--------------------------------

### initializeFirestore(app, settings, databaseId)

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/firestore_lite.md

Initializes a new Firestore instance with the provided settings and database ID. This must be called before any other Firestore functions. This API is in preview.

```APIDOC
## initializeFirestore(app, settings, databaseId)

### Description
Initializes a new instance of Cloud Firestore with the provided settings. Can only be called before any other functions, including getFirestore(). If the custom settings are empty, this function is equivalent to calling getFirestore(). This API is provided as a preview for developers and may change based on feedback that we receive. Do not use this API in a production environment.

### Method
initializeFirestore

### Parameters
#### Path Parameters
- **app** (FirebaseApp) - Required - The FirebaseApp with which the Firestore instance will be associated.
- **settings** (Settings) - Required - A settings object to configure the Firestore instance.
- **databaseId** (string) - Optional - The name of the database.

### Returns
- **Firestore** - A newly initialized `Firestore` instance.
```

--------------------------------

### Example: Replace Document with Map Expression

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/firestore_pipelines.pipeline.md

This example shows replacing a document with a map derived from an expression. The expression constructs a map including static values and fields from the input document.

```typescript
// Input.
// {
//  'name': 'John Doe Jr.',
//  'parents': {
//    'father': 'John Doe Sr.',
//    'mother': 'Jane Doe'
//   }
// }
// Emit parents as document.irestore.pipeline().collection('people').replaceWith(map({
foo: 'bar',
info: {
name: field('name')
}
}));
// Output
// {
//  'father': 'John Doe Sr.',
//  'mother': 'Jane Doe'
// }
```

--------------------------------

### Connect to Realtime Database Emulator

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/database.md

Configures a Database instance to communicate with a local Realtime Database emulator. This must be invoked before any other database operations are performed.

```typescript
export declare function connectDatabaseEmulator(db: Database, host: string, port: number, options?: {
    mockUserToken?: EmulatorMockTokenOptions | string;
}): void;
```

--------------------------------

### Get a subcollection reference from a DocumentReference

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/firestore_lite.md

Use `collection` with a `DocumentReference` to get a reference to a subcollection nested under a specific document. This allows for targeted access to data within a document's hierarchy.

```typescript
export declare function collection<AppModelType, DbModelType extends DocumentData>(reference: DocumentReference<AppModelType, DbModelType>, path: string, ...pathSegments: string[]): CollectionReference<DocumentData, DocumentData>;
```

--------------------------------

### initializeAuth(app, deps)

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/auth.md

Initializes an Auth instance with fine-grained control over dependencies, allowing for custom persistence and resolver configurations.

```APIDOC
## initializeAuth(app, deps)

### Description
Initializes an Auth instance with fine-grained control over Dependencies. Use this if you need control over the persistence layer or to minimize bundle size.

### Parameters
#### Path Parameters
- **app** (FirebaseApp) - Required - The Firebase App.
- **deps** (Dependencies) - Optional - The dependencies to configure the Auth instance.

### Response
- **Auth** (Auth) - The initialized Auth instance.
```

--------------------------------

### Get Data Type of Expression

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/firestore_pipelines.expression.md

Use `type()` to get the backend data type of an expression as a string. Note that custom Firestore mappings are ignored, and numeric types are reported as 'int64' or 'float64'.

```typescript
// Get the data type of the value in field 'title'
field('title').type()
```

--------------------------------

### Get a document reference from another document

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/firestore_lite.md

Gets a DocumentReference instance that refers to a document within another document at the specified relative path. This is useful for creating references to subcollections or nested documents.

```typescript
export declare function doc<AppModelType, DbModelType extends DocumentData>(reference: DocumentReference<AppModelType, DbModelType>, path: string, ...pathSegments: string[]): DocumentReference<DocumentData, DocumentData>;
```

--------------------------------

### LiveGenerationConfig.contextWindowCompression

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/ai.livegenerationconfig.md

Configuration for context window compression. This API is provided as a preview and may change based on feedback.

```APIDOC
## LiveGenerationConfig.contextWindowCompression

> This API is provided as a preview for developers and may change based on feedback that we receive. Do not use this API in a production environment.

### Description
The context window compression configuration.

### Signature

```typescript
contextWindowCompression?: ContextWindowCompressionConfig;
```
```

--------------------------------

### startAfter

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/firestore_.md

Creates a QueryStartAtConstraint that modifies the result set to start after the provided document (exclusive). The starting position is relative to the order of the query. The document must contain all of the fields provided in the orderBy of the query.

```APIDOC
## function startAfter(snapshot)

### Description
Creates a `QueryStartAtConstraint` that modifies the result set to start after the provided document (exclusive). The starting position is relative to the order of the query. The document must contain all of the fields provided in the `orderBy` of the query.

### Method
`startAfter`

### Parameters
#### Path Parameters
- **snapshot** ([DocumentSnapshot](./firestore_.documentsnapshot.md#documentsnapshot_class)) - Required - The snapshot of the document to start after.

### Returns
- **QueryStartAtConstraint** - A `QueryStartAtConstraint` to pass to `query()`
```

--------------------------------

### Run Full SDK Browser Tests (Emulator)

Source: https://github.com/firebase/firebase-js-sdk/blob/main/packages/firestore/CONTRIBUTING.md

Executes the full Cloud Firestore SDK tests in a browser environment (Chrome Headless) against the emulator.

```bash
yarn test:browser
```

--------------------------------

### onConfigUpdate(remoteConfig, observer)

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/remote-config.md

Starts listening for real-time config updates from the Remote Config backend. It automatically fetches updates when they are available and reuses an existing connection if one is open.

```APIDOC
## onConfigUpdate(remoteConfig, observer)

### Description
Starts listening for real-time config updates from the Remote Config backend and automatically fetches updates from the Remote Config backend when they are available. If a connection to the Remote Config backend is not already open, calling this method will open it. Multiple listeners can be added by calling this method again, but subsequent calls re-use the same connection to the backend.

### Signature
```typescript
export declare function onConfigUpdate(remoteConfig: RemoteConfig, observer: ConfigUpdateObserver): Unsubscribe;
```

### Parameters
#### Path Parameters
- **remoteConfig** (RemoteConfig) - Required - The RemoteConfig instance.
- **observer** (ConfigUpdateObserver) - Required - The ConfigUpdateObserver to be notified of config updates.

### Returns
Unsubscribe - An Unsubscribe function to remove the listener.
```

--------------------------------

### startAfter(snapshot)

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/firestore_lite.md

Creates a QueryStartAtConstraint that modifies the result set to start after the provided document (exclusive). The starting position is relative to the order of the query. The document must contain all of the fields provided in the orderBy of the query.

```APIDOC
## startAfter(snapshot)

### Description
Creates a `QueryStartAtConstraint` that modifies the result set to start after the provided document (exclusive). The starting position is relative to the order of the query. The document must contain all of the fields provided in the `orderBy` of the query.

### Signature
```typescript
export declare function startAfter<AppModelType, DbModelType extends DocumentData>(snapshot: DocumentSnapshot<AppModelType, DbModelType>): QueryStartAtConstraint;
```

### Parameters
#### Path Parameters
- **snapshot** (DocumentSnapshot<AppModelType, DbModelType>) - Required - The snapshot of the document to start after.

### Returns
- **QueryStartAtConstraint** - A `QueryStartAtConstraint` to pass to `query()`
```

--------------------------------

### getAI

Source: https://github.com/firebase/firebase-js-sdk/blob/main/common/api-review/ai.api.md

Initializes and retrieves an AI instance. This is the entry point for using AI services.

```APIDOC
## getAI

### Description
Initializes and retrieves an AI instance. This is the entry point for using AI services.

### Method
`getAI`

### Parameters
- **app** (FirebaseApp) - Optional - The Firebase app instance.
- **options** (AIOptions) - Optional - Configuration options for the AI service.

### Returns
- **AI** - An instance of the AI service.
```

--------------------------------

### Start Audio Conversation

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/ai.md

Starts a real-time, bidirectional audio conversation. This function must be called in response to a user gesture due to browser autoplay policies. It manages microphone access, recording, and playback.

```typescript
export declare function startAudioConversation(liveSession: LiveSession, options?: StartAudioConversationOptions): Promise<AudioConversationController>;
```

--------------------------------

### Initialize Auth with React Native Persistence

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/auth.md

Example showing how to initialize Firebase Auth with React Native storage persistence.

```javascript
import { initializeAuth, getReactNativePersistence } from 'firebase/auth';

// For @react-native-async-storage/async-storage v3:
import { createAsyncStorage } from '@react-native-async-storage/async-storage';
const appStorage = createAsyncStorage('app');
const persistence = getReactNativePersistence(appStorage);

// For @react-native-async-storage/async-storage v2:
// import ReactNativeAsyncStorage from '@react-native-async-storage/async-storage';
// const persistence = getReactNativePersistence(ReactNativeAsyncStorage);

// Then, initialize auth:
const auth = initializeAuth(app, {
  persistence
});
```

--------------------------------

### initializeAppCheck

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/app-check.md

Activate App Check for the given app. This function can be called only once per app.

```APIDOC
## initializeAppCheck(app, options)

### Description
Activate App Check for the given app. Can be called only once per app.

### Method
Not applicable (SDK function)

### Parameters
#### Path Parameters
None

#### Query Parameters
None

#### Request Body
None

### Request Example
```typescript
initializeAppCheck(firebaseApp, { provider: myProvider, isTokenAutoRefreshEnabled: true });
```

### Response
#### Success Response
- **AppCheck** (object) - The Firebase App Check service interface.

#### Response Example
```json
{
  // AppCheck service object
}
```
```

--------------------------------

### Define exclusive start point for Firebase queries

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/database.md

Creates a QueryConstraint that sets a starting point for a query, excluding the specified value. It allows for filtering based on values greater than the input, with optional key-based refinement.

```typescript
export declare function startAfter(value: number | string | boolean | null, key?: string): QueryConstraint;
```

--------------------------------

### Define FID Change Unsubscribe Function (TypeScript)

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/installations.md

Defines the type for a function that, when called, will stop listening for Firebase Installations FID changes. This is used to clean up event listeners.

```typescript
export type IdChangeUnsubscribeFn = () => void;
```

--------------------------------

### Run Full SDK Node Tests (Emulator)

Source: https://github.com/firebase/firebase-js-sdk/blob/main/packages/firestore/CONTRIBUTING.md

Executes the full Cloud Firestore SDK tests in a Node.js environment against the emulator.

```bash
yarn test:node
```

--------------------------------

### Define FID Change Callback Function (TypeScript)

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/installations.md

Defines the type for a callback function that will be invoked when the Firebase Installations FID changes. This function accepts the new FID as a string argument.

```typescript
export type IdChangeCallbackFn = (installationId: string) => void;
```

--------------------------------

### Example: Replace Document with Nested Map Field

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/firestore_pipelines.pipeline.md

This example demonstrates how to use replaceWith to emit a nested map as the document content. The input document's 'parents' field, containing a map, is used to replace the entire document.

```typescript
// Input.
// {
//  'name': 'John Doe Jr.',
//  'parents': {
//    'father': 'John Doe Sr.',
//    'mother': 'Jane Doe'
//   }
// }
// Emit parents as document.irestore.pipeline().collection('people').replaceWith('parents');
// Output
// {
//  'father': 'John Doe Sr.',
//  'mother': 'Jane Doe'
// }
```

--------------------------------

### Initialize On-Device Model

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/ai.generativemodel.md

Initializes on-device models. This may trigger a download on first use and must be called after user interaction. Use the onDownloadProgress callback to monitor download status.

```typescript
initializeDeviceModel(onDownloadProgress?: (progressValue: number) => void): Promise<void>;
```

--------------------------------

### Get First N Elements of Array with arrayFirstN (Expression)

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/firestore_pipelines.md

Use arrayFirstN with an Expression to get the first 'n' elements from an array field, where 'n' is dynamically determined by another expression. This allows for flexible selection of array subsets.

```typescript
arrayFirstN("tags", field("count"));
```

--------------------------------

### sample(options)

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/firestore_pipelines.pipeline.md

Performs a pseudo-random sampling of documents from the previous stage. The 'options' parameter specifies how sampling will be performed.

```APIDOC
## sample(options)

### Description
Performs a pseudo-random sampling of documents from the previous stage.

### Parameters
#### Path Parameters
- **options** (SampleStageOptions) - Required - Specifies how sampling will be performed. See [SampleStageOptions](./firestore_pipelines.md#samplestageoptions) for more information.
```

--------------------------------

### getValue

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/remote-config.md

Gets the Value object for the given key.

```APIDOC
## getValue(remoteConfig, key)

### Description
Gets the [Value](./remote-config.value.md#value_interface) for the given key.

### Parameters
#### Path Parameters
- **remoteConfig** (object) - Required - The Remote Config instance.
- **key** (string) - Required - The key of the configuration value.

### Returns
- (object) - The Value object for the given key.
```

--------------------------------

### Sign in with Email and Password, Link with Redirect

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/auth.md

Demonstrates signing in a user with email and password, then linking their account with a Facebook provider via redirect. After the redirect, it shows how to get the redirect result.

```javascript
// Sign in using some other provider.
const result = await signInWithEmailAndPassword(auth, email, password);
// Link using a redirect.
const provider = new FacebookAuthProvider();
await linkWithRedirect(result.user, provider);
// This will trigger a full page redirect away from your app

// After returning from the redirect when your app initializes you can obtain the result
const result = await getRedirectResult(auth);
```

--------------------------------

### getString

Source: https://github.com/firebase/firebase-js-sdk/blob/main/docs-devsite/remote-config.md

Gets the value for the given key as a string.

```APIDOC
## getString(remoteConfig, key)

### Description
Gets the value for the given key as a string. Convenience method for calling <code>remoteConfig.getValue(key).asString()</code>.

### Parameters
#### Path Parameters
- **remoteConfig** (object) - Required - The Remote Config instance.
- **key** (string) - Required - The key of the configuration value.

### Returns
- (string) - The string value for the given key.
```