Building a Simple Login/Register Flow in Flutter Using Riverpod

User authentication is one of the most critical flows in any app. Whether you’re building a social media platform, an e-commerce app, or a chat tool, a clean and responsive login/register experience can make or break your app’s first impression. Integrating a login register flow in Flutter using Riverpod can streamline this process, providing robust state management.

In this guide, you’ll learn how to build a simple login and register flow in Flutter using Riverpod, complete with async state handling, error management, and a modular folder structure. We’ll build the whole thing in a scalable and testable way — perfect for production-ready apps in 2025.

🤔 Why Choose Riverpod Over Provider?

Riverpod is more than just a replacement for Provider — it’s a complete rethink of how to handle state in Flutter. In the context of authentication, Riverpod provides several benefits:

• No BuildContext needed to access providers
• Testable by default — no need for widget tests to test logic
• Robust async handling with AsyncValue
• Fine-grained control over scopes and listeners
• Cleaner architecture for larger apps

📘 Deep dive: Why I Use Riverpod (Not Provider) in 2025

📦 Packages You’ll Need

dependencies:
  flutter:
    sdk: flutter
  flutter_riverpod: ^2.4.0
  flutter_hooks: ^0.20.5

🛠️ Folder Structure

/lib
  /features
    /auth
      auth_screen.dart
      auth_form.dart
      auth_controller.dart
      auth_repository.dart

We’re using a feature-first folder structure for scalability.
📂 See why this is recommended

🔐 Step 1: Create the Auth Repository

class AuthRepository {
  Future login(String email, String password) async {
    await Future.delayed(const Duration(seconds: 1));
    if (email != 'test@example.com' || password != 'password') {
      throw Exception('Invalid credentials');
    }
  }

  Future register(String email, String password) async {
    await Future.delayed(const Duration(seconds: 1));
    // Simulate success
  }
}

final authRepositoryProvider = Provider((ref) => AuthRepository());

🧠 Step 2: Create the Auth Controller

final authControllerProvider = StateNotifierProvider>(
  (ref) => AuthController(ref.read),
);

class AuthController extends StateNotifier> {
  AuthController(this._read) : super(const AsyncData(null));

  final Reader _read;

  Future login(String email, String password) async {
    state = const AsyncLoading();
    try {
      await _read(authRepositoryProvider).login(email, password);
      state = const AsyncData(null);
    } catch (e) {
      state = AsyncError(e);
    }
  }

  Future register(String email, String password) async {
    state = const AsyncLoading();
    try {
      await _read(authRepositoryProvider).register(email, password);
      state = const AsyncData(null);
    } catch (e) {
      state = AsyncError(e);
    }
  }
}

🎯 Step 3: Build the Login/Register Form

class AuthForm extends HookConsumerWidget {
  final bool isLogin;
  const AuthForm({super.key, required this.isLogin});

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final email = useTextEditingController();
    final password = useTextEditingController();
    final state = ref.watch(authControllerProvider);

    return Column(
      children: [
        TextField(controller: email, decoration: const InputDecoration(labelText: 'Email')),
        TextField(controller: password, decoration: const InputDecoration(labelText: 'Password'), obscureText: true),
        const SizedBox(height: 20),
        state.isLoading
            ? const CircularProgressIndicator()
            : ElevatedButton(
                onPressed: () {
                  isLogin
                      ? ref.read(authControllerProvider.notifier).login(email.text, password.text)
                      : ref.read(authControllerProvider.notifier).register(email.text, password.text);
                },
                child: Text(isLogin ? 'Login' : 'Register'),
              ),
        if (state.hasError) Text(state.error.toString(), style: const TextStyle(color: Colors.red)),
      ],
    );
  }
}

🖼️ Step 4: Use the Auth Screen

class AuthScreen extends StatelessWidget {
  const AuthScreen({super.key});

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Login / Register')),
      body: Padding(
        padding: const EdgeInsets.all(16.0),
        child: AuthForm(isLogin: true), // Change to false for register screen
      ),
    );
  }
}

✅ Final Touches

• Add form validation
• Navigate to the home screen after login
• Replace mock logic with real API calls or Firebase auth

📘 Looking for integration with Firebase?
Check out: Building a Chat App in Flutter with Firebase

🧠 Final Thought

Using Riverpod for your login/register flow gives you asynchronous control, better testing, and clean separation of concerns. It’s perfect for modern Flutter apps in 2025 — and scales beautifully with your app.