Auth0 Flutter Native (iOS/Android) Integration

auth0_flutter is the official Auth0 SDK for Flutter applications. On mobile (iOS/Android), it performs authentication through the device's system browser (Web Auth / Universal Login) and stores tokens securely in the platform keychain/keystore via the built-in CredentialsManager, with optional biometric protection.

Agent instruction: Before providing SDK setup instructions, fetch the latest release version by running one of:

gh api repos/auth0/auth0-flutter/releases/latest --jq '.tag_name'

flutter pub info auth0_flutter 2>/dev/null | head -5

Or check pub.dev:

curl -s https://pub.dev/api/packages/auth0_flutter | python3 -c "import sys,json;print(json.load(sys.stdin)['latest']['version'])"

Use the returned version in all dependency lines instead of any hardcoded version below. Current known version: 2.1.0.

When NOT to Use

• Flutter web: Use auth0-flutter-web — web uses a different platform interface (Auth0Web) wrapping Auth0 SPA JS
• Native iOS (Swift, no Flutter): Use auth0-swift
• Native Android (Kotlin/Java, no Flutter): Use auth0-android
• React Native: Use auth0-react-native
• React SPA: Use auth0-react
• Node.js/Express servers: Use auth0-express

Prerequisites

• Flutter 3.24.0+
• Dart 3.5.0+
• Android: minSdkVersion 21+, compileSdkVersion 34+
• iOS: 14.0+ (Universal Link callbacks require iOS 17.4+)
• Auth0 account — Sign up free
• Auth0 CLI — install instructions (used to create and configure the Auth0 application)

Quick Start Workflow

Agent instruction: Follow these steps in order. If you encounter an error at any step, attempt to fix it up to 5 times before calling AskUserQuestion to ask the user for guidance. Always search existing code first — if there are existing login/logout handlers, hook into them rather than creating new ones.

Step 1 — Install SDK

Agent instruction: Check the project directory for pubspec.yaml. If present, add the dependency. If not found, this is not a Flutter project — ask the user.

Run in the project root:

flutter pub add auth0_flutter

Verify the dependency was added to pubspec.yaml:

dependencies:
  auth0_flutter: ^2.1.0

Step 2 — Configure Auth0

Note: The Auth0 Domain and Client ID are public configuration (not secrets) — a native app uses PKCE with no client secret. Pass them directly to Auth0(domain, clientId); there is no need to store them in environment variables or hide them.

Agent instruction:

• If Auth0 credentials (domain AND client ID) are already in the user's prompt: Use those values directly in the Auth0(...) constructor and proceed to Step 3.
• If no credentials are provided: Ask the user which setup they prefer using AskUserQuestion: "How would you like to set up the Auth0 application — automatic (I run the Auth0 CLI to create it) or manual (you create it in the Auth0 Dashboard and give me the Domain + Client ID)?"
  • Automatic: Follow the Auth0 CLI steps in the Setup Guide to create the Native application.
  • Manual: Ask the user for their Auth0 Domain and Client ID and use them directly.

Follow Setup Guide — Auth0 Configuration for the pre-flight checks and the auth0 apps create command.

Step 3 — Configure Android

Agent instruction: Edit android/app/build.gradle (or build.gradle.kts) and add manifestPlaceholders inside android { defaultConfig { ... } }. These supply the callback URL the SDK's RedirectActivity intent filter registers — without them the app will not build correctly for Auth0.

For android/app/build.gradle (Groovy):

android {
    defaultConfig {
        manifestPlaceholders = [auth0Domain: "YOUR_AUTH0_DOMAIN", auth0Scheme: "https"]
    }
}

For android/app/build.gradle.kts (Kotlin DSL):

android {
    defaultConfig {
        manifestPlaceholders["auth0Domain"] = "YOUR_AUTH0_DOMAIN"
        manifestPlaceholders["auth0Scheme"] = "https"
    }
}

Agent instruction: Use auth0Scheme: "https" to use Android App Links (recommended). If the app targets a custom scheme instead, set it to a lowercase scheme string and pass the same scheme to webAuthentication(scheme: ...) in Dart. See Setup Guide for details.

Step 4 — Configure iOS

Agent instruction: For the default HTTPS (Universal Link) flow on iOS 17.4+, no Info.plist change is required, but the Associated Domains capability must be added in Xcode (webcredentials:YOUR_AUTH0_DOMAIN). For older iOS or a custom URL scheme, add a CFBundleURLTypes entry to ios/Runner/Info.plist:

<key>CFBundleURLTypes</key>
<array>
  <dict>
    <key>CFBundleTypeRole</key>
    <string>None</string>
    <key>CFBundleURLName</key>
    <string>auth0</string>
    <key>CFBundleURLSchemes</key>
    <array>
      <string>$(PRODUCT_BUNDLE_IDENTIFIER)</string>
    </array>
  </dict>
</array>

Step 5 — Configure Callback URLs

Agent instruction: Register the platform-specific callback and logout URLs using the Auth0 CLI. Determine the Android package name (from android/app/build.gradle applicationId) and the iOS bundle identifier (from Xcode / PRODUCT_BUNDLE_IDENTIFIER), then run the command below, replacing the placeholders (CLIENT_ID, YOUR_DOMAIN, ANDROID_PACKAGE_NAME, IOS_BUNDLE_ID) with the project's values:

auth0 apps update CLIENT_ID \
  --callbacks "https://YOUR_DOMAIN/android/ANDROID_PACKAGE_NAME/callback,https://YOUR_DOMAIN/ios/IOS_BUNDLE_ID/callback" \
  --logout-urls "https://YOUR_DOMAIN/android/ANDROID_PACKAGE_NAME/callback,https://YOUR_DOMAIN/ios/IOS_BUNDLE_ID/callback" \
  --no-input

The callback URL formats are:

• Android: https://YOUR_DOMAIN/android/YOUR_PACKAGE_NAME/callback
• iOS: https://YOUR_DOMAIN/ios/YOUR_BUNDLE_ID/callback

Step 6 — Implement Authentication

Agent instruction: Search the project for the main app entry point (main.dart). Determine the state management approach:

• Look for provider, riverpod, bloc, GetX, or mobx imports
• If none found, use basic StatefulWidget with setState

Then follow only the matching path below. If ambiguous, ask via AskUserQuestion: "Which state management approach does your Flutter app use — Provider, Riverpod, Bloc, or basic setState?"

Basic StatefulWidget (Default)

Agent instruction: Create an AuthService class, then wire it into the app's root widget. Search for the MaterialApp or CupertinoApp widget and update accordingly. On startup, restore the session from the CredentialsManager cache.

// lib/auth_service.dart
import 'package:auth0_flutter/auth0_flutter.dart';

class AuthService {
  late final Auth0 _auth0;
  Credentials? _credentials;

  AuthService({required String domain, required String clientId}) {
    _auth0 = Auth0(domain, clientId);
  }

  bool get isAuthenticated => _credentials != null;
  UserProfile? get user => _credentials?.user;

  /// Restore a stored session on app startup, if one exists.
  Future<void> init() async {
    final hasValid = await _auth0.credentialsManager.hasValidCredentials();
    if (hasValid) {
      _credentials = await _auth0.credentialsManager.credentials();
    }
  }

  /// Launch Web Auth via the system browser. Tokens are stored automatically.
  Future<void> login() async {
    _credentials = await _auth0
        .webAuthentication()
        .login(scopes: {'openid', 'profile', 'email', 'offline_access'});
  }

  /// Clear the session in the browser and wipe stored credentials.
  Future<void> logout() async {
    await _auth0.webAuthentication().logout();
    await _auth0.credentialsManager.clearCredentials();
    _credentials = null;
  }
}

// lib/main.dart
import 'package:flutter/material.dart';
import 'package:auth0_flutter/auth0_flutter.dart'; // for WebAuthenticationException
import 'auth_service.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatefulWidget {
  const MyApp({super.key});

  @override
  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  final _authService = AuthService(
    domain: 'YOUR_AUTH0_DOMAIN',
    clientId: 'YOUR_AUTH0_CLIENT_ID',
  );
  bool _isLoading = true;

  @override
  void initState() {
    super.initState();
    _initAuth();
  }

  Future<void> _initAuth() async {
    await _authService.init();
    setState(() => _isLoading = false);
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: _isLoading
          ? const Scaffold(body: Center(child: CircularProgressIndicator()))
          : _authService.isAuthenticated
              ? HomeScreen(authService: _authService, onChanged: _refresh)
              : LoginScreen(authService: _authService, onChanged: _refresh),
    );
  }

  void _refresh() => setState(() {});
}

class LoginScreen extends StatelessWidget {
  final AuthService authService;
  final VoidCallback onChanged;
  const LoginScreen({super.key, required this.authService, required this.onChanged});

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: ElevatedButton(
          onPressed: () async {
            // Capture the messenger before the await to avoid using
            // BuildContext across an async gap.
            final messenger = ScaffoldMessenger.of(context);
            try {
              await authService.login();
              onChanged();
            } on WebAuthenticationException catch (e) {
              messenger.showSnackBar(
                SnackBar(content: Text('Login failed: ${e.message}')),
              );
            }
          },
          child: const Text('Log In'),
        ),
      ),
    );
  }
}

class HomeScreen extends StatelessWidget {
  final AuthService authService;
  final VoidCallback onChanged;
  const HomeScreen({super.key, required this.authService, required this.onChanged});

  @override
  Widget build(BuildContext context) {
    final user = authService.user;
    return Scaffold(
      appBar: AppBar(
        title: const Text('Home'),
        actions: [
          IconButton(
            onPressed: () async {
              await authService.logout();
              onChanged();
            },
            icon: const Icon(Icons.logout),
          ),
        ],
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            if (user?.pictureUrl != null)
              CircleAvatar(
                backgroundImage: NetworkImage(user!.pictureUrl.toString()),
                radius: 40,
              ),
            const SizedBox(height: 16),
            Text('Welcome, ${user?.name ?? 'User'}!'),
            Text(user?.email ?? ''),
          ],
        ),
      ),
    );
  }
}

Provider (State Management)

Agent instruction: If the project uses provider, create AuthService as a ChangeNotifier and inject it via ChangeNotifierProvider at the app root.

// lib/auth_service.dart
import 'package:flutter/foundation.dart';
import 'package:auth0_flutter/auth0_flutter.dart';

class AuthService extends ChangeNotifier {
  late final Auth0 _auth0;
  Credentials? _credentials;
  bool _isLoading = true;

  AuthService({required String domain, required String clientId}) {
    _auth0 = Auth0(domain, clientId);
  }

  bool get isAuthenticated => _credentials != null;
  bool get isLoading => _isLoading;
  UserProfile? get user => _credentials?.user;

  Future<void> init() async {
    if (await _auth0.credentialsManager.hasValidCredentials()) {
      _credentials = await _auth0.credentialsManager.credentials();
    }
    _isLoading = false;
    notifyListeners();
  }

  Future<void> login() async {
    _credentials = await _auth0
        .webAuthentication()
        .login(scopes: {'openid', 'profile', 'email', 'offline_access'});
    notifyListeners();
  }

  Future<void> logout() async {
    await _auth0.webAuthentication().logout();
    await _auth0.credentialsManager.clearCredentials();
    _credentials = null;
    notifyListeners();
  }
}

// lib/main.dart — wrap with ChangeNotifierProvider
import 'package:provider/provider.dart';

void main() {
  runApp(
    ChangeNotifierProvider(
      create: (_) => AuthService(
        domain: 'YOUR_AUTH0_DOMAIN',
        clientId: 'YOUR_AUTH0_CLIENT_ID',
      )..init(),
      child: const MyApp(),
    ),
  );
}

For complete patterns with Riverpod, Bloc, biometrics, and advanced scenarios, see Integration Patterns.

Step 7 — Verify Build

Agent instruction: Run a build to verify the integration compiles without errors:

flutter build apk --debug      # Android
flutter build ios --no-codesign  # iOS (on macOS)

Then run the app on a device or emulator to test:

flutter run

If the build fails, review error messages and fix up to 5 times before asking the user.

Physical device testing: Biometric protection (Face ID / Touch ID / fingerprint) cannot be exercised on a simulator/emulator — the iOS Simulator and Android emulator have limited or no biometric hardware. Test biometrics and the full Universal Login redirect on a real physical device before release.

Detailed Documentation

• Setup Guide — Auth0 application creation via the Auth0 CLI, Android manifestPlaceholders, iOS Info.plist / Associated Domains, callback URL registration
• Integration Patterns — Web Auth login/logout, CredentialsManager, biometric protection, custom schemes, organizations, API access tokens, state management patterns, error handling
• API Reference & Testing — Full API reference, configuration options, claims reference, testing checklist, troubleshooting

Common Mistakes

Mistake	Fix
Auth0 app type not set to Native	Create the application with auth0 apps create --type native (or select "Native" in the Auth0 Dashboard)
Missing manifestPlaceholders on Android	Add manifestPlaceholders = [auth0Domain: "...", auth0Scheme: "https"] to android/app/build.gradle defaultConfig — the build fails without it
Using Auth0Web on mobile	Mobile uses the Auth0 class with webAuthentication(), not Auth0Web (that's the web-only API)
Importing auth0_flutter_web.dart on mobile	Only import package:auth0_flutter/auth0_flutter.dart — the _web import is for Flutter web
Callback URL mismatch	Register https://YOUR_DOMAIN/android/PACKAGE_NAME/callback and https://YOUR_DOMAIN/ios/BUNDLE_ID/callback in Allowed Callback URLs
Scheme mismatch between Gradle and Dart	If auth0Scheme is a custom scheme, pass the same value to webAuthentication(scheme: 'myscheme')
Custom scheme with uppercase letters on Android	Android custom schemes must be all lowercase
Biometrics prompt never appears on Android	MainActivity must extend FlutterFragmentActivity (not FlutterActivity) for the biometric prompt to work
Not storing credentials after login	webAuthentication().login() stores credentials automatically; do NOT also re-store unless renewing manually via api.renewCredentials
Not restoring session on startup	Call credentialsManager.hasValidCredentials() + credentials() in initState() to restore the session
Missing offline_access scope	Add 'offline_access' to scopes so the CredentialsManager can silently renew expired access tokens with a refresh token
Catching generic Exception	Catch WebAuthenticationException (login/logout) and CredentialsManagerException (credential errors) and inspect isUserCancelledException, isNoCredentialsFound, isTokenRenewFailed, etc.

Related Skills

• auth0-quickstart — Initial Auth0 setup and account creation
• auth0-flutter-web — Same SDK, web platform
• auth0-swift — Native iOS (Swift)
• auth0-android — Native Android (Kotlin/Java)

Quick Reference

API	Purpose
Auth0(domain, clientId)	Create the SDK client
auth0.webAuthentication().login(...)	Launch Universal Login in the system browser
auth0.webAuthentication().logout()	Clear the browser session
auth0.webAuthentication(scheme: '...')	Use a custom URL scheme
auth0.credentialsManager.credentials()	Get stored credentials (auto-renews if expired)
auth0.credentialsManager.hasValidCredentials()	Check for a valid stored session
auth0.credentialsManager.clearCredentials()	Wipe stored credentials
LocalAuthentication(title: ...)	Enable biometric protection of stored credentials

References

• auth0_flutter on pub.dev
• auth0_flutter GitHub
• Flutter Quickstart (Native)
• Auth0 Dashboard