Flutter Quickstart

Use this guide to add ThunderID authentication to a Flutter application using the thunderid_flutter package.

What You Will Learn

• Create a new Flutter project

• Install the thunderid_flutter package

• Add working sign-in and sign-out using Flutter widgets

• Display the signed-in user's name

Prerequisites

• About 20 minutes

• Flutter 3.16+ and Dart 3.2+

• iOS 16+ or Android API 26+ target device or simulator

1

Run ThunderID

Start a local ThunderID instance. Pick the method that works best for you:

$npx thunderid

Requires Node.js 18+

Full install guide →

Once it's running, the console is available at https://localhost:8090/console.

2

Create an Application

1. Sign in to the Console.

   Test User

   If you used the default setup, sign in to the Console as admin with the password generated during setup and printed to the setup output (unless you supplied your own).

2. Navigate to Applications.

3. Click Add Application.

4. From the Choose a type page, select Flutter.

5. Enter a name (e.g. My Flutter App).

6. Select how you want to sign in users (e.g., email/password, social login, etc.).

7. Select Theme settings.

8. Leave Sign-In Approach set to Bring Your Own UI (the default for Flutter applications).

9. Click Create.

warning

Copy the Application ID from the General tab, under Quick Copy. You'll need it when configuring the SDK.

3

Create a Flutter App

Create a new Flutter project:

flutter create my_flutter_app
cd my_flutter_app

note

If you already have an existing Flutter project, skip this step.

4

Install thunderid_flutter Package

Add the package, which writes a version constraint to your pubspec.yaml and records the resolved version in pubspec.lock:

flutter pub add thunderid_flutter

5

Initialize the SDK

Wrap your root widget with ThunderIDProvider in lib/main.dart:

lib/main.dart

import 'package:flutter/material.dart';
import 'package:thunderid_flutter/thunderid_flutter.dart';

void main() {
  runApp(
    ThunderIDProvider(
      config: ThunderIDConfig(
        baseUrl: 'https://localhost:8090',
        scopes: const ['openid', 'profile', 'email'],
        applicationId: '<your-application-id>',
      ),
      child: const MyApp(),
    ),
  );
}

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

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      home: RootScreen(),
    );
  }
}

Configuration

Replace <your-application-id> with the Application ID from your ThunderID application settings.

Configuration Parameters

Parameter	Description
baseUrl	Your ThunderID instance URL. Must use HTTPS.
scopes	OAuth 2.0 scopes to request. Include 'openid' at minimum.
applicationId	The Application ID used for the app-native sign-in and sign-up flows

6

Add Sign-In and Sign-Out

Create a root screen that reads auth state from ThunderIDProvider.of(context) and routes to either your auth or home screen.

Create lib/root_screen.dart:

lib/root_screen.dart

import 'package:flutter/material.dart';
import 'package:thunderid_flutter/thunderid_flutter.dart';
import 'auth_screen.dart';
import 'home_screen.dart';

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

  @override
  Widget build(BuildContext context) {
    final thunder = ThunderIDProvider.of(context);

    if (!thunder.initialized || thunder.isLoading) {
      return const Scaffold(
        body: Center(child: CircularProgressIndicator()),
      );
    }

    return thunder.isSignedIn ? const HomeScreen() : const AuthScreen();
  }
}

Create lib/auth_screen.dart to display the sign-in form:

lib/auth_screen.dart

import 'package:flutter/material.dart';
import 'package:thunderid_flutter/thunderid_flutter.dart';

enum _AuthMode { signIn, signUp }

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

  @override
  State<AuthScreen> createState() => _AuthScreenState();
}

class _AuthScreenState extends State<AuthScreen> {
  _AuthMode _mode = _AuthMode.signIn;

  @override
  Widget build(BuildContext context) {
    final thunder = ThunderIDProvider.of(context);
    final applicationId = thunder.config?.applicationId ?? '';

    return Scaffold(
      body: SafeArea(
        child: SingleChildScrollView(
          padding: const EdgeInsets.symmetric(horizontal: 28, vertical: 40),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.stretch,
            children: [
              SegmentedButton<_AuthMode>(
                segments: const [
                  ButtonSegment(value: _AuthMode.signIn, label: Text('Sign In')),
                  ButtonSegment(value: _AuthMode.signUp, label: Text('Create Account')),
                ],
                selected: {_mode},
                onSelectionChanged: (s) => setState(() => _mode = s.first),
              ),
              const SizedBox(height: 28),
              if (_mode == _AuthMode.signIn)
                SignIn(applicationId: applicationId)
              else
                SignUp(applicationId: applicationId),
            ],
          ),
        ),
      ),
    );
  }
}

7

Display User Profile Information

Create lib/home_screen.dart to show the authenticated user's name and a sign-out button:

lib/home_screen.dart

import 'package:flutter/material.dart';
import 'package:thunderid_flutter/thunderid_flutter.dart';

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

  @override
  Widget build(BuildContext context) {
    final thunder = ThunderIDProvider.of(context);
    final user = thunder.user;

    return Scaffold(
      appBar: AppBar(title: const Text('Home')),
      body: Padding(
        padding: const EdgeInsets.all(24),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: [
            if (user != null) ...[
              Text(
                'Welcome, ${user.displayName ?? user.email ?? 'User'}!',
                style: Theme.of(context).textTheme.titleLarge?.copyWith(
                      fontWeight: FontWeight.bold,
                    ),
              ),
              const SizedBox(height: 8),
              Text(
                user.email ?? '',
                style: Theme.of(context).textTheme.bodyMedium?.copyWith(
                      color: Theme.of(context).colorScheme.onSurfaceVariant,
                    ),
              ),
              const SizedBox(height: 24),
            ],
            SignOutButton(),
          ],
        ),
      ),
    );
  }
}

8

Run the App

Start an iOS simulator or connect an Android device, then run:

flutter run

Test credentials

You'll need a user to sign in with. If you haven't created one yet, open https://localhost:8090/console, navigate to Users, and add a test user with an email and password.

Success

You should see the sign-in form. Enter your test user credentials and tap Submit. After successful authentication, the home screen displays the user's name and a Sign Out button.

What's Next

Upgrade the sign-in flowAdd MFA, passkeys, or social login to your flow, no app code changes required.Flow Designer →

Flutter SDK ReferenceExplore the full API reference for the Flutter SDK.API Reference →