Expand Firebase page with setup, Auth, and database guides

sites/docs/src/content/data-and-backend/firebase.md

@@ -1,60 +1,286 @@
 ---
 title: Firebase
-description: How to use Firebase and Firestore with Flutter.
+description: >-
+  Connect your Flutter app to Firebase for authentication, Cloud Firestore,
+  Firebase SQL Connect, cloud storage, AI features, and serverless Dart
+  functions.
 ---
 
-Firebase is a Backend-as-a-Service (BaaS) app development platform
-that provides hosted backend services such as cloud databases
-([Cloud Firestore][] and [Firebase SQL Connect][]),
-cloud storage, authentication, crash reporting, AI features,
-remote configuration, and hosting for your static files.
+Firebase is Google's app development platform that provides managed
+backend services for Flutter apps on mobile, web, and desktop.
+Each Firebase service is available as a separate Firebase Flutter
+plugin on pub.dev, so you can add only the services your app needs:
 
-## Flutter and Firebase resources
+| Service | Use case | Package |
+|---|---|---|
+| [Cloud Firestore][] | NoSQL document database with realtime sync and built-in offline cache | [`cloud_firestore`][] |
+| [Firebase SQL Connect][] | Managed PostgreSQL database with generated, type-safe Dart SDKs | [`firebase_data_connect`][] |
+| [Firebase Authentication][firebase-auth] | User sign-in with email, phone, and providers like Google or Apple | [`firebase_auth`][] |
+| [Cloud Storage for Firebase][firebase-storage] | File uploads and downloads for user photos, videos, and documents | [`firebase_storage`][] |
+| [Firebase AI Logic][firebase-ai] | Direct client access to Gemini and Imagen models | [`firebase_ai`][] |
+| [Cloud Functions for Firebase][firebase-functions-dart] | Serverless backend logic written in JavaScript, TypeScript, Python, or Dart (experimental) | [`cloud_functions`][] (client), [`firebase_functions`][] (server) |
+| [Firebase Crashlytics][crashlytics] | Realtime crash reporting and diagnostics | [`firebase_crashlytics`][] |
 
-Firebase supports Flutter. To learn more,
-check out the following resources.
+{:.table .table-striped}
 
-### Documentation
+For a complete list of supported packages and platform availability,
+check out [Available Firebase Flutter plugins][Firebase plugins].
 
-* [Getting started with Firebase and Flutter][started]
-* [Choose a database for your Flutter app][choose-db]
-* [Firebase plugins][]
+## Connect a Flutter app to Firebase
+
+To register your Flutter app with a Firebase project and generate
+platform configuration files, use the Firebase CLI and FlutterFire CLI:
+
+1. Install the [Firebase CLI][] and sign in to your Google Account:
+
+   ```console
+   $ firebase login
+   ```
+
+2. Install the FlutterFire CLI globally:
+
+   ```console
+   $ dart pub global activate flutterfire_cli
+   ```
+
+3. From the root of your Flutter project, add the core plugin and run
+   the configuration workflow:
+
+   ```console
+   $ flutter pub add firebase_core
+   $ flutterfire configure
+   ```
+
+   This command registers your per-platform apps in your Firebase
+   project and generates `lib/firebase_options.dart`.
+
+4. Initialize Firebase in `lib/main.dart` before calling `runApp()`:
+
+   ```dart
+   import 'package:firebase_core/firebase_core.dart';
+   import 'package:flutter/material.dart';
+   import 'firebase_options.dart';
+
+   void main() async {
+     WidgetsFlutterBinding.ensureInitialized();
+     await Firebase.initializeApp(
+       options: DefaultFirebaseOptions.currentPlatform,
+     );
+     runApp(const MyApp());
+   }
+   ```
+
+For detailed platform setup instructions, refer to
+[Add Firebase to your Flutter app][started].
+
+## Authenticate users with Firebase Authentication
+
+[Firebase Authentication][firebase-auth] supports sign-in with email
+and password, phone numbers, anonymous sessions, and federated
+identity providers such as Google, Apple, and GitHub.
+
+To add Firebase Authentication to your app, install [`firebase_auth`][]:
+
+```console
+$ flutter pub add firebase_auth
+```
+
+You can listen to `FirebaseAuth.instance.authStateChanges()` with a
+`StreamBuilder` to react whenever a user signs in or out:
+
+```dart
+import 'package:firebase_auth/firebase_auth.dart';
+import 'package:flutter/material.dart';
+
+class AuthGate extends StatelessWidget {
+  const AuthGate({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return StreamBuilder<User?>(
+      stream: FirebaseAuth.instance.authStateChanges(),
+      builder: (context, snapshot) {
+        if (snapshot.connectionState == ConnectionState.waiting) {
+          return const Center(child: CircularProgressIndicator());
+        }
+        if (snapshot.hasData) {
+          return HomeScreen(user: snapshot.data!);
+        }
+        // Your own sign-in UI.
+        return const SignInScreen();
+      },
+    );
+  }
+}
 
-### Blog Posts
+Future<UserCredential> signInWithEmail(String email, String password) {
+  return FirebaseAuth.instance.signInWithEmailAndPassword(
+    email: email,
+    password: password,
+  );
+}
+```
 
-[Use Firebase to host your Flutter app on the web][article]
+To learn more, check out
+[Get started with Firebase Authentication on Flutter][firebase-auth] or
+the [FirebaseUI authentication codelab][auth-codelab].
 
-### Tutorials
+## Store and sync NoSQL data with Cloud Firestore
 
-Get to know Firebase for Flutter
-* [tutorial][codelab1]
-* [video workshop][workshop]
+[Cloud Firestore][] is the recommended default when your app needs a
+scalable NoSQL database that syncs data across devices in realtime and
+works offline—such as in chat apps, collaborative tools, or
+offline-first field service apps. To compare Cloud Firestore with
+relational and local storage options, check out
+[Choose a database for your Flutter app][choose-db].
 
-## Flutter and Firebase community resources
+To add Cloud Firestore to your project, run:
 
-The Flutter community created the following useful resources.
+```console
+$ flutter pub add cloud_firestore
+```
 
-### Blog Posts
+The following example adds a task document to a `tasks` collection and
+streams live query results into a `ListView`:
 
-[Building chat app with Flutter and Firebase][chat app]
+```dart
+import 'package:cloud_firestore/cloud_firestore.dart';
+import 'package:flutter/material.dart';
+
+Future<void> addTask(String title) {
+  return FirebaseFirestore.instance.collection('tasks').add({
+    'title': title,
+    'completed': false,
+    'createdAt': FieldValue.serverTimestamp(),
+  });
+}
+
+class TaskList extends StatelessWidget {
+  const TaskList({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    final tasksStream = FirebaseFirestore.instance
+        .collection('tasks')
+        .orderBy('createdAt', descending: true)
+        .snapshots();
+
+    return StreamBuilder<QuerySnapshot<Map<String, dynamic>>>(
+      stream: tasksStream,
+      builder: (context, snapshot) {
+        if (snapshot.hasError) {
+          return const Center(child: Text('Something went wrong.'));
+        }
+        if (snapshot.connectionState == ConnectionState.waiting) {
+          return const Center(child: CircularProgressIndicator());
+        }
+
+        final docs = snapshot.data!.docs;
+        return ListView.builder(
+          itemCount: docs.length,
+          itemBuilder: (context, index) {
+            final data = docs[index].data();
+            return ListTile(
+              title: Text(data['title'] as String? ?? ''),
+            );
+          },
+        );
+      },
+    );
+  }
+}
+```
+
+Offline persistence is enabled by default on Android and Apple
+platforms (and can be enabled on the web), so your app can read and
+write cached documents without a network connection and automatically
+sync changes when connectivity returns. To get started, follow the
+[Cloud Firestore quickstart][firestore-quickstart].
+
+## Query relational SQL data with Firebase SQL Connect
+
+If your app needs a relational database, [Firebase SQL Connect][]
+(formerly Firebase Data Connect) provides a managed PostgreSQL
+database and generates a type-safe Dart SDK, built on the
+[`firebase_data_connect`][] package, from your schema and queries.
+
+To install the plugin, run:
+
+```console
+$ flutter pub add firebase_data_connect
+```
+
+To compare SQL Connect with Cloud Firestore and local SQLite, check out
+[Choose a database for your Flutter app][choose-db]. To set up a
+SQL Connect backend and call it from Flutter, follow the guide to
+[use generated Flutter SDKs][sql-connect-flutter].
+
+## Share Dart code with a serverless Firebase backend
+
+When your app needs custom server-side logic, background triggers, or
+administrative access to Firebase services, you can write
+[Cloud Functions for Firebase in Dart][firebase-functions-dart] using
+the [`firebase_functions`][] and [`firebase_admin_sdk`][] packages.
+
+:::note
+Dart support for Cloud Functions for Firebase is experimental.
+You must enable the `dartfunctions` experiment in the Firebase CLI
+before running `firebase init functions`, and the APIs might change
+before a stable release.
+:::
+
+Using Dart on both your Flutter frontend and your Firebase backend lets
+you share a single Dart package for data models, JSON serialization,
+and validation rules across client and server. To learn how to
+structure a shared-package workspace, check out
+[Sharing code between Flutter apps and Dart backends][dart-server].
+
+## Flutter and Firebase resources
+
+To learn more about building Flutter apps with Firebase, check out the
+following official and community resources.
+
+### Documentation and codelabs
+
+* [Add Firebase to your Flutter app][started]
+* [Choose a database for your Flutter app][choose-db]
+* [Get to know Firebase for Flutter codelab][codelab1]
+* [Add a user authentication flow using FirebaseUI][auth-codelab]
+* [Firebase AI Logic documentation][firebase-ai]
+* [Use Firebase to host your Flutter app on the web][article]
 
 ### Videos
 
+* [Get to know Firebase for Flutter video workshop][workshop]
 * [Using Firestore as a backend to your Flutter app][video]
 * [Live Coding Firebase Authentication with Flutter][video2]
-* [Flutter & Firebase Auth 01][video3]
-* [Flutter: Firebase Tutorial Part 1 - Auth and Sign in][video4]
 
 [article]: {{site.flutter-blog}}/must-try-use-firebase-to-host-your-flutter-app-on-the-web-852ee533a469
-[chat app]: https://medium.com/flutter-community/building-a-chat-app-with-flutter-and-firebase-from-scratch-9eaa7f41782e
+[auth-codelab]: {{site.firebase}}/codelabs/firebase-auth-in-flutter-apps
 [choose-db]: /data-and-backend/persistence/choose-a-database
 [Cloud Firestore]: {{site.firebase}}/docs/firestore
+[`cloud_firestore`]: {{site.pub-pkg}}/cloud_firestore
+[`cloud_functions`]: {{site.pub-pkg}}/cloud_functions
 [codelab1]: {{site.codelabs}}/codelabs/firebase-get-to-know-flutter
+[crashlytics]: {{site.firebase}}/docs/crashlytics/flutter/get-started
+[dart-server]: {{site.dart-site}}/server#sharing-code-between-flutter-apps-and-dart-backends
+[firebase-ai]: {{site.firebase}}/docs/ai-logic/get-started
+[`firebase_ai`]: {{site.pub-pkg}}/firebase_ai
+[`firebase_admin_sdk`]: {{site.pub-pkg}}/firebase_admin_sdk
+[firebase-auth]: {{site.firebase}}/docs/auth/flutter/start
+[`firebase_auth`]: {{site.pub-pkg}}/firebase_auth
+[Firebase CLI]: {{site.firebase}}/docs/cli
+[`firebase_crashlytics`]: {{site.pub-pkg}}/firebase_crashlytics
+[`firebase_data_connect`]: {{site.pub-pkg}}/firebase_data_connect
+[firebase-functions-dart]: {{site.firebase}}/docs/functions/start-dart
+[`firebase_functions`]: {{site.pub-pkg}}/firebase_functions
 [Firebase plugins]: {{site.firebase}}/docs/flutter/setup#available-plugins
 [Firebase SQL Connect]: {{site.firebase}}/docs/sql-connect
+[firebase-storage]: {{site.firebase}}/docs/storage/flutter/start
+[`firebase_storage`]: {{site.pub-pkg}}/firebase_storage
+[firestore-quickstart]: {{site.firebase}}/docs/firestore/quickstart
+[sql-connect-flutter]: {{site.firebase}}/docs/sql-connect/flutter-sdk
 [started]: {{site.firebase}}/docs/flutter/setup
 [video]: {{site.yt.watch}}/DqJ_KjFzL9I&t#38s
 [video2]: {{site.yt.watch}}/OlcYP6UXlm8
-[video3]: {{site.yt.watch}}/u_Lyx8KJWpg
-[video4]: {{site.yt.watch}}/13-jNF984C0
 [workshop]: {{site.yt.watch}}/4wunbF29Kkg

sites/docs/src/content/llms.txt

@@ -70,7 +70,7 @@ This file provides a curated list of resources to help Large Language Models und
 - [Choose a database for your Flutter app](https://docs.flutter.dev/data-and-backend/persistence/choose-a-database): Compare database options for Flutter apps, including Cloud Firestore (recommended default for cloud NoSQL and offline sync), Firebase SQL Connect (recommended default for cloud PostgreSQL with generated type-safe Dart SDKs), on-device SQLite (`sqflite` and `drift`), and key-value storage (`shared_preferences` and `flutter_secure_storage`).
 - [Fetch data from the internet](https://docs.flutter.dev/cookbook/networking/fetch-data): Make a basic HTTP request.
 - [Networking with Flutter](https://docs.flutter.dev/data-and-backend/networking): How to make HTTP requests and handle JSON data.
-- [Firebase for Flutter](https://docs.flutter.dev/data-and-backend/firebase): A guide to using Firebase as a backend for your Flutter app.
+- [Firebase for Flutter](https://docs.flutter.dev/data-and-backend/firebase): Connect your Flutter app to Firebase with `flutterfire configure`, authenticate users with `firebase_auth`, sync NoSQL data with `cloud_firestore`, query PostgreSQL with `firebase_data_connect`, and share Dart code with the experimental `firebase_functions` SDK.
 - [Persist data with SQLite](https://docs.flutter.dev/cookbook/persistence/sqlite): Learn the basics of local database storage.
 - [Store key-value data on disk](https://docs.flutter.dev/cookbook/persistence/key-value): For simple data storage using `shared_preferences`.