Build a User Management App with Flutter

This tutorial demonstrates how to build a basic user management app. The app authenticates and identifies the user, stores their profile information in the database, and allows the user to log in, update their profile details, and upload a profile photo. The app uses:

Supabase Database - a Postgres database for storing your user data and Row Level Security so data is protected and users can only access their own information.
Supabase Auth - users log in through magic links sent to their email (without having to set up passwords).
Supabase Storage - users can upload a profile photo.

Supabase User Management example

If you get stuck while working through this guide, refer to the full example on GitHub.

Project setup

Before we start building we're going to set up our Database and API. This is as simple as starting a new Project in Supabase and then creating a "schema" inside the database.

Create a project

Create a new project in the Supabase Dashboard.
Enter your project details.
Wait for the new database to launch.

Set up the database schema

Now we are going to set up the database schema. We can use the "User Management Starter" quickstart in the SQL Editor, or you can just copy/paste the SQL from below and run it yourself.

Go to the SQL Editor page in the Dashboard.
Click User Management Starter.
Click Run.

You can easily pull the database schema down to your local project by running the db pull command. Read the local development docs for detailed instructions.


_10supabase link --project-ref <project-id>
_10# You can get <project-id> from your project's dashboard URL: https://supabase.com/dashboard/project/<project-id>
_10supabase db pull

Get the API Keys

Now that you've created some database tables, you are ready to insert data using the auto-generated API. We just need to get the Project URL and anon key from the API settings.

Go to the API Settings page in the Dashboard.
Find your Project URL, anon, and service_role keys on this page.

Building the app

Let's start building the Flutter app from scratch.

Initialize a Flutter app

We can use flutter create to initialize an app called supabase_quickstart:


_10flutter create supabase_quickstart

Then let's install the only additional dependency: supabase_flutter

Copy and paste the following line in your pubspec.yaml to install the package:


_10supabase_flutter: ^2.0.0

Run flutter pub get to install the dependencies.

Setup deep links

Now that we have the dependencies installed let's setup deep links. Setting up deep links is required to bring back the user to the app when they click on the magic link to sign in. We can setup deep links with just a minor tweak on our Flutter application.

We have to use io.supabase.flutterquickstart as the scheme. In this example, we will use login-callback as the host for our deep link, but you can change it to whatever you would like.

First, add io.supabase.flutterquickstart://login-callback/ as a new redirect URL in the Dashboard.

Supabase console deep link setting

That is it on Supabase's end and the rest are platform specific settings:

Edit the ios/Runner/Info.plist file.

Add CFBundleURLTypes to enable deep linking:

ios/Runner/Info.plist"


_20<!-- ... other tags -->
_20<plist>
_20<dict>
_20  <!-- ... other tags -->
_20
_20  <!-- Add this array for Deep Links -->
_20  <key>CFBundleURLTypes</key>
_20  <array>
_20    <dict>
_20      <key>CFBundleTypeRole</key>
_20      <string>Editor</string>
_20      <key>CFBundleURLSchemes</key>
_20      <array>
_20        <string>io.supabase.flutterquickstart</string>
_20      </array>
_20    </dict>
_20  </array>
_20  <!-- ... other tags -->
_20</dict>
_20</plist>

Main function

Now that we have deep links ready let's initialize the Supabase client inside our main function with the API credentials that you copied earlier. These variables will be exposed on the app, and that's completely fine since we have Row Level Security enabled on our Database.

lib/main.dart


_34import 'package:flutter/material.dart';
_34import 'package:supabase_flutter/supabase_flutter.dart';
_34
_34Future<void> main() async {
_34  await Supabase.initialize(
_34    url: 'YOUR_SUPABASE_URL',
_34    anonKey: 'YOUR_SUPABASE_ANON_KEY',
_34  );
_34  runApp(const MyApp());
_34}
_34
_34final supabase = Supabase.instance.client;
_34
_34class MyApp extends StatelessWidget {
_34  const MyApp({super.key});
_34
_34  @override
_34  Widget build(BuildContext context) {
_34    return const MaterialApp(title: 'Supabase Flutter');
_34  }
_34}
_34
_34extension ContextExtension on BuildContext {
_34  void showSnackBar(String message, {bool isError = false}) {
_34    ScaffoldMessenger.of(this).showSnackBar(
_34      SnackBar(
_34        content: Text(message),
_34        backgroundColor: isError
_34            ? Theme.of(this).colorScheme.error
_34            : Theme.of(this).snackBarTheme.backgroundColor,
_34      ),
_34    );
_34  }
_34}

Notice that we have a showSnackBar extension method that we will use to show snack bars in the app. You could define this method in a separate file and import it where needed, but for simplicity, we will define it here.

Let's create a Flutter widget to manage logins and sign ups. We will use Magic Links, so users can sign in with their email without using passwords.

Notice that this page sets up a listener on the user's auth state using onAuthStateChange. A new event will fire when the user comes back to the app by clicking their magic link, which this page can catch and redirect the user accordingly.

lib/pages/login_page.dart


_105import 'dart:async';
_105
_105import 'package:flutter/foundation.dart';
_105import 'package:flutter/material.dart';
_105import 'package:supabase_flutter/supabase_flutter.dart';
_105import 'package:supabase_quickstart/main.dart';
_105import 'package:supabase_quickstart/pages/account_page.dart';
_105
_105class LoginPage extends StatefulWidget {
_105  const LoginPage({super.key});
_105
_105  @override
_105  State<LoginPage> createState() => _LoginPageState();
_105}
_105
_105class _LoginPageState extends State<LoginPage> {
_105  bool _isLoading = false;
_105  bool _redirecting = false;
_105  late final TextEditingController _emailController = TextEditingController();
_105  late final StreamSubscription<AuthState> _authStateSubscription;
_105
_105  Future<void> _signIn() async {
_105    try {
_105      setState(() {
_105        _isLoading = true;
_105      });
_105      await supabase.auth.signInWithOtp(
_105        email: _emailController.text.trim(),
_105        emailRedirectTo:
_105            kIsWeb ? null : 'io.supabase.flutterquickstart://login-callback/',
_105      );
_105      if (mounted) {
_105        context.showSnackBar('Check your email for a login link!');
_105
_105        _emailController.clear();
_105      }
_105    } on AuthException catch (error) {
_105      if (mounted) context.showSnackBar(error.message, isError: true);
_105    } catch (error) {
_105      if (mounted) {
_105        context.showSnackBar('Unexpected error occurred', isError: true);
_105      }
_105    } finally {
_105      if (mounted) {
_105        setState(() {
_105          _isLoading = false;
_105        });
_105      }
_105    }
_105  }
_105
_105  @override
_105  void initState() {
_105    _authStateSubscription = supabase.auth.onAuthStateChange.listen(
_105      (data) {
_105        if (_redirecting) return;
_105        final session = data.session;
_105        if (session != null) {
_105          _redirecting = true;
_105          Navigator.of(context).pushReplacement(
_105            MaterialPageRoute(builder: (context) => const AccountPage()),
_105          );
_105        }
_105      },
_105      onError: (error) {
_105        if (error is AuthException) {
_105          context.showSnackBar(error.message, isError: true);
_105        } else {
_105          context.showSnackBar('Unexpected error occurred', isError: true);
_105        }
_105      },
_105    );
_105    super.initState();
_105  }
_105
_105  @override
_105  void dispose() {
_105    _emailController.dispose();
_105    _authStateSubscription.cancel();
_105    super.dispose();
_105  }
_105
_105  @override
_105  Widget build(BuildContext context) {
_105    return Scaffold(
_105      appBar: AppBar(title: const Text('Sign In')),
_105      body: ListView(
_105        padding: const EdgeInsets.symmetric(vertical: 18, horizontal: 12),
_105        children: [
_105          const Text('Sign in via the magic link with your email below'),
_105          const SizedBox(height: 18),
_105          TextFormField(
_105            controller: _emailController,
_105            decoration: const InputDecoration(labelText: 'Email'),
_105          ),
_105          const SizedBox(height: 18),
_105          ElevatedButton(
_105            onPressed: _isLoading ? null : _signIn,
_105            child: Text(_isLoading ? 'Sending...' : 'Send Magic Link'),
_105          ),
_105        ],
_105      ),
_105    );
_105  }
_105}

Set up account page

After a user is signed in we can allow them to edit their profile details and manage their account. Let's create a new widget called account_page.dart for that.

lib/pages/account_page.dart"


_138import 'package:flutter/material.dart';
_138import 'package:supabase_flutter/supabase_flutter.dart';
_138import 'package:supabase_quickstart/main.dart';
_138import 'package:supabase_quickstart/pages/login_page.dart';
_138
_138class AccountPage extends StatefulWidget {
_138  const AccountPage({super.key});
_138
_138  @override
_138  State<AccountPage> createState() => _AccountPageState();
_138}
_138
_138class _AccountPageState extends State<AccountPage> {
_138  final _usernameController = TextEditingController();
_138  final _websiteController = TextEditingController();
_138
_138  String? _avatarUrl;
_138  var _loading = true;
_138
_138  /// Called once a user id is received within `onAuthenticated()`
_138  Future<void> _getProfile() async {
_138    setState(() {
_138      _loading = true;
_138    });
_138
_138    try {
_138      final userId = supabase.auth.currentSession!.user.id;
_138      final data =
_138          await supabase.from('profiles').select().eq('id', userId).single();
_138      _usernameController.text = (data['username'] ?? '') as String;
_138      _websiteController.text = (data['website'] ?? '') as String;
_138      _avatarUrl = (data['avatar_url'] ?? '') as String;
_138    } on PostgrestException catch (error) {
_138      if (mounted) context.showSnackBar(error.message, isError: true);
_138    } catch (error) {
_138      if (mounted) {
_138        context.showSnackBar('Unexpected error occurred', isError: true);
_138      }
_138    } finally {
_138      if (mounted) {
_138        setState(() {
_138          _loading = false;
_138        });
_138      }
_138    }
_138  }
_138
_138  /// Called when user taps `Update` button
_138  Future<void> _updateProfile() async {
_138    setState(() {
_138      _loading = true;
_138    });
_138    final userName = _usernameController.text.trim();
_138    final website = _websiteController.text.trim();
_138    final user = supabase.auth.currentUser;
_138    final updates = {
_138      'id': user!.id,
_138      'username': userName,
_138      'website': website,
_138      'updated_at': DateTime.now().toIso8601String(),
_138    };
_138    try {
_138      await supabase.from('profiles').upsert(updates);
_138      if (mounted) context.showSnackBar('Successfully updated profile!');
_138    } on PostgrestException catch (error) {
_138      if (mounted) context.showSnackBar(error.message, isError: true);
_138    } catch (error) {
_138      if (mounted) {
_138        context.showSnackBar('Unexpected error occurred', isError: true);
_138      }
_138    } finally {
_138      if (mounted) {
_138        setState(() {
_138          _loading = false;
_138        });
_138      }
_138    }
_138  }
_138
_138  Future<void> _signOut() async {
_138    try {
_138      await supabase.auth.signOut();
_138    } on AuthException catch (error) {
_138      if (mounted) context.showSnackBar(error.message, isError: true);
_138    } catch (error) {
_138      if (mounted) {
_138        context.showSnackBar('Unexpected error occurred', isError: true);
_138      }
_138    } finally {
_138      if (mounted) {
_138        Navigator.of(context).pushReplacement(
_138          MaterialPageRoute(builder: (_) => const LoginPage()),
_138        );
_138      }
_138    }
_138  }
_138
_138  @override
_138  void initState() {
_138    super.initState();
_138    _getProfile();
_138  }
_138
_138  @override
_138  void dispose() {
_138    _usernameController.dispose();
_138    _websiteController.dispose();
_138    super.dispose();
_138  }
_138
_138  @override
_138  Widget build(BuildContext context) {
_138    return Scaffold(
_138      appBar: AppBar(title: const Text('Profile')),
_138      body: ListView(
_138        padding: const EdgeInsets.symmetric(vertical: 18, horizontal: 12),
_138        children: [
_138          TextFormField(
_138            controller: _usernameController,
_138            decoration: const InputDecoration(labelText: 'User Name'),
_138          ),
_138          const SizedBox(height: 18),
_138          TextFormField(
_138            controller: _websiteController,
_138            decoration: const InputDecoration(labelText: 'Website'),
_138          ),
_138          const SizedBox(height: 18),
_138          ElevatedButton(
_138            onPressed: _loading ? null : _updateProfile,
_138            child: Text(_loading ? 'Saving...' : 'Update'),
_138          ),
_138          const SizedBox(height: 18),
_138          TextButton(onPressed: _signOut, child: const Text('Sign Out')),
_138        ],
_138      ),
_138    );
_138  }
_138}

Launch!

Now that we have all the components in place, let's update lib/main.dart. The home of the MaterialApp, meaning the initial page shown to the user, will be the LoginPage if the user is not authenticated, and the AccountPage if the user is authenticated. We also included some theming to make the app look a bit nicer.

lib/main.dart


_55import 'package:flutter/material.dart';
_55import 'package:supabase_flutter/supabase_flutter.dart';
_55import 'package:supabase_quickstart/pages/account_page.dart';
_55import 'package:supabase_quickstart/pages/login_page.dart';
_55
_55Future<void> main() async {
_55  await Supabase.initialize(
_55    url: 'YOUR_SUPABASE_URL',
_55    anonKey: 'YOUR_SUPABASE_ANON_KEY',
_55  );
_55  runApp(const MyApp());
_55}
_55
_55final supabase = Supabase.instance.client;
_55
_55class MyApp extends StatelessWidget {
_55  const MyApp({super.key});
_55
_55  @override
_55  Widget build(BuildContext context) {
_55    return MaterialApp(
_55      title: 'Supabase Flutter',
_55      theme: ThemeData.dark().copyWith(
_55        primaryColor: Colors.green,
_55        textButtonTheme: TextButtonThemeData(
_55          style: TextButton.styleFrom(
_55            foregroundColor: Colors.green,
_55          ),
_55        ),
_55        elevatedButtonTheme: ElevatedButtonThemeData(
_55          style: ElevatedButton.styleFrom(
_55            foregroundColor: Colors.white,
_55            backgroundColor: Colors.green,
_55          ),
_55        ),
_55      ),
_55      home: supabase.auth.currentSession == null
_55          ? const LoginPage()
_55          : const AccountPage(),
_55    );
_55  }
_55}
_55
_55extension ContextExtension on BuildContext {
_55  void showSnackBar(String message, {bool isError = false}) {
_55    ScaffoldMessenger.of(this).showSnackBar(
_55      SnackBar(
_55        content: Text(message),
_55        backgroundColor: isError
_55            ? Theme.of(this).colorScheme.error
_55            : Theme.of(this).snackBarTheme.backgroundColor,
_55      ),
_55    );
_55  }
_55}

Once that's done, run this in a terminal window to launch on Android or iOS:


_10flutter run

Or for web, run the following command to launch it on localhost:3000


_10flutter run -d web-server --web-hostname localhost --web-port 3000

And then open the browser to localhost:3000 and you should see the completed app.

Supabase User Management example

Bonus: Profile photos

Every Supabase project is configured with Storage for managing large files like photos and videos.

Making sure we have a public bucket

We will be storing the image as a publicly sharable image. Make sure your avatars bucket is set to public, and if it is not, change the publicity by clicking the dot menu that appears when you hover over the bucket name. You should see an orange Public badge next to your bucket name if your bucket is set to public.

Adding image uploading feature to account page

We will use image_picker plugin to select an image from the device.

Add the following line in your pubspec.yaml file to install image_picker:


_10image_picker: ^1.0.5

Using image_picker requires some additional preparation depending on the platform. Follow the instruction on README.md of image_picker on how to set it up for the platform you are using.

Once you are done with all of the above, it is time to dive into coding.

Let's create an avatar for the user so that they can upload a profile photo. We can start by creating a new component:

lib/components/avatar.dart


_89import 'package:flutter/material.dart';
_89import 'package:image_picker/image_picker.dart';
_89import 'package:supabase_flutter/supabase_flutter.dart';
_89import 'package:supabase_quickstart/main.dart';
_89
_89class Avatar extends StatefulWidget {
_89  const Avatar({
_89    super.key,
_89    required this.imageUrl,
_89    required this.onUpload,
_89  });
_89
_89  final String? imageUrl;
_89  final void Function(String) onUpload;
_89
_89  @override
_89  State<Avatar> createState() => _AvatarState();
_89}
_89
_89class _AvatarState extends State<Avatar> {
_89  bool _isLoading = false;
_89
_89  @override
_89  Widget build(BuildContext context) {
_89    return Column(
_89      children: [
_89        if (widget.imageUrl == null || widget.imageUrl!.isEmpty)
_89          Container(
_89            width: 150,
_89            height: 150,
_89            color: Colors.grey,
_89            child: const Center(
_89              child: Text('No Image'),
_89            ),
_89          )
_89        else
_89          Image.network(
_89            widget.imageUrl!,
_89            width: 150,
_89            height: 150,
_89            fit: BoxFit.cover,
_89          ),
_89        ElevatedButton(
_89          onPressed: _isLoading ? null : _upload,
_89          child: const Text('Upload'),
_89        ),
_89      ],
_89    );
_89  }
_89
_89  Future<void> _upload() async {
_89    final picker = ImagePicker();
_89    final imageFile = await picker.pickImage(
_89      source: ImageSource.gallery,
_89      maxWidth: 300,
_89      maxHeight: 300,
_89    );
_89    if (imageFile == null) {
_89      return;
_89    }
_89    setState(() => _isLoading = true);
_89
_89    try {
_89      final bytes = await imageFile.readAsBytes();
_89      final fileExt = imageFile.path.split('.').last;
_89      final fileName = '${DateTime.now().toIso8601String()}.$fileExt';
_89      final filePath = fileName;
_89      await supabase.storage.from('avatars').uploadBinary(
_89            filePath,
_89            bytes,
_89            fileOptions: FileOptions(contentType: imageFile.mimeType),
_89          );
_89      final imageUrlResponse = await supabase.storage
_89          .from('avatars')
_89          .createSignedUrl(filePath, 60 * 60 * 24 * 365 * 10);
_89      widget.onUpload(imageUrlResponse);
_89    } on StorageException catch (error) {
_89      if (mounted) {
_89        context.showSnackBar(error.message, isError: true);
_89      }
_89    } catch (error) {
_89      if (mounted) {
_89        context.showSnackBar('Unexpected error occurred', isError: true);
_89      }
_89    }
_89
_89    setState(() => _isLoading = false);
_89  }
_89}

And then we can add the widget to the Account page as well as some logic to update the avatar_url whenever the user uploads a new avatar.

lib/pages/account_page.dart


_138import 'package:flutter/material.dart';
_138import 'package:supabase_flutter/supabase_flutter.dart';
_138import 'package:supabase_quickstart/main.dart';
_138import 'package:supabase_quickstart/pages/login_page.dart';
_138
_138class AccountPage extends StatefulWidget {
_138  const AccountPage({super.key});
_138
_138  @override
_138  State<AccountPage> createState() => _AccountPageState();
_138}
_138
_138class _AccountPageState extends State<AccountPage> {
_138  final _usernameController = TextEditingController();
_138  final _websiteController = TextEditingController();
_138
_138  String? _avatarUrl;
_138  var _loading = true;
_138
_138  /// Called once a user id is received within `onAuthenticated()`
_138  Future<void> _getProfile() async {
_138    setState(() {
_138      _loading = true;
_138    });
_138
_138    try {
_138      final userId = supabase.auth.currentSession!.user.id;
_138      final data =
_138          await supabase.from('profiles').select().eq('id', userId).single();
_138      _usernameController.text = (data['username'] ?? '') as String;
_138      _websiteController.text = (data['website'] ?? '') as String;
_138      _avatarUrl = (data['avatar_url'] ?? '') as String;
_138    } on PostgrestException catch (error) {
_138      if (mounted) context.showSnackBar(error.message, isError: true);
_138    } catch (error) {
_138      if (mounted) {
_138        context.showSnackBar('Unexpected error occurred', isError: true);
_138      }
_138    } finally {
_138      if (mounted) {
_138        setState(() {
_138          _loading = false;
_138        });
_138      }
_138    }
_138  }
_138
_138  /// Called when user taps `Update` button
_138  Future<void> _updateProfile() async {
_138    setState(() {
_138      _loading = true;
_138    });
_138    final userName = _usernameController.text.trim();
_138    final website = _websiteController.text.trim();
_138    final user = supabase.auth.currentUser;
_138    final updates = {
_138      'id': user!.id,
_138      'username': userName,
_138      'website': website,
_138      'updated_at': DateTime.now().toIso8601String(),
_138    };
_138    try {
_138      await supabase.from('profiles').upsert(updates);
_138      if (mounted) context.showSnackBar('Successfully updated profile!');
_138    } on PostgrestException catch (error) {
_138      if (mounted) context.showSnackBar(error.message, isError: true);
_138    } catch (error) {
_138      if (mounted) {
_138        context.showSnackBar('Unexpected error occurred', isError: true);
_138      }
_138    } finally {
_138      if (mounted) {
_138        setState(() {
_138          _loading = false;
_138        });
_138      }
_138    }
_138  }
_138
_138  Future<void> _signOut() async {
_138    try {
_138      await supabase.auth.signOut();
_138    } on AuthException catch (error) {
_138      if (mounted) context.showSnackBar(error.message, isError: true);
_138    } catch (error) {
_138      if (mounted) {
_138        context.showSnackBar('Unexpected error occurred', isError: true);
_138      }
_138    } finally {
_138      if (mounted) {
_138        Navigator.of(context).pushReplacement(
_138          MaterialPageRoute(builder: (_) => const LoginPage()),
_138        );
_138      }
_138    }
_138  }
_138
_138  @override
_138  void initState() {
_138    super.initState();
_138    _getProfile();
_138  }
_138
_138  @override
_138  void dispose() {
_138    _usernameController.dispose();
_138    _websiteController.dispose();
_138    super.dispose();
_138  }
_138
_138  @override
_138  Widget build(BuildContext context) {
_138    return Scaffold(
_138      appBar: AppBar(title: const Text('Profile')),
_138      body: ListView(
_138        padding: const EdgeInsets.symmetric(vertical: 18, horizontal: 12),
_138        children: [
_138          TextFormField(
_138            controller: _usernameController,
_138            decoration: const InputDecoration(labelText: 'User Name'),
_138          ),
_138          const SizedBox(height: 18),
_138          TextFormField(
_138            controller: _websiteController,
_138            decoration: const InputDecoration(labelText: 'Website'),
_138          ),
_138          const SizedBox(height: 18),
_138          ElevatedButton(
_138            onPressed: _loading ? null : _updateProfile,
_138            child: Text(_loading ? 'Saving...' : 'Update'),
_138          ),
_138          const SizedBox(height: 18),
_138          TextButton(onPressed: _signOut, child: const Text('Sign Out')),
_138        ],
_138      ),
_138    );
_138  }
_138}

Congratulations, you've built a fully functional user management app using Flutter and Supabase!

Build a User Management App with Flutter

Project setup

Create a project

Set up the database schema

Get the API Keys

Building the app

Initialize a Flutter app

Setup deep links

Main function

Set up account page

Launch!

Bonus: Profile photos

Making sure we have a public bucket

Adding image uploading feature to account page

Create an upload widget

Add the new widget

See also

Build a User Management App with Flutter

Project setup#

Create a project#

Set up the database schema#

Get the API Keys#

Building the app#

Initialize a Flutter app#

Setup deep links#

Main function#

Set up a login page#

Set up account page#

Launch!#

Bonus: Profile photos#

Making sure we have a public bucket#

Adding image uploading feature to account page#

Create an upload widget#

Add the new widget#

See also#

Project setup

Create a project

Set up the database schema

Get the API Keys

Building the app

Initialize a Flutter app

Setup deep links

Main function

Set up a login page

Set up account page

Launch!

Bonus: Profile photos

Making sure we have a public bucket

Adding image uploading feature to account page

Create an upload widget

Add the new widget

See also