> ## Documentation Index
> Fetch the complete documentation index at: https://turnkey-0e7c1f5b-traian-remove-eip-712-note.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.
# Overview
> Learn how to set up, log in, or sign up easily in your Flutter app using Turnkey's Flutter SDK.
export const FeatureCard = ({title, description, icon, logo, href}) => {
return
{logo ? 
: }
{title}
{description &&
{description}
}
;
};
Turnkey's Flutter SDK makes authentication simple. You can call specific login and signup functions (email/SMS OTP, passkeys, or social logins) to build your own UI and auth flow.
## Authentication state
To check if a user is authenticated, you can use the `authState` variable from the `TurnkeyProvider`.
`authState` can be one of the following:
* `AuthState.authenticated`: The user has a stored session.
* `AuthState.unauthenticated`: The user does not have a stored session.
* `AuthState.loading`: The provider is initializing. Turnkey is checking for any existing stored sessions or restoring state. UI should show a splash or progress indicator.
You can consume `authState` in any widget using a `Consumer`:
```dart title=lib/widgets/auth_status.dart theme={null}
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import 'package:turnkey_sdk_flutter/turnkey_sdk_flutter.dart';
class AuthStatus extends StatelessWidget {
const AuthStatus({super.key});
@override
Widget build(BuildContext context) {
return Consumer(
builder: (context, tk, _) {
switch (tk.authState) {
case AuthState.loading:
return const Center(
child: CircularProgressIndicator(),
);
case AuthState.unauthenticated:
return ElevatedButton(
onPressed: () {
// Navigate to your login screen or trigger your chosen auth flow
Navigator.of(context).pushNamed('/login');
},
child: const Text('Log in'),
);
case AuthState.authenticated:
final user = tk.user;
return Text('Welcome back, ${user?.userName ?? 'user'}!');
}
},
);
}
}
```
You can also set up an `onSessionSelected` callback in `TurnkeyConfig` to handle post-authentication logic, such as redirecting.
```dart title=snippet (in main.dart where you construct TurnkeyProvider) theme={null}
final turnkeyProvider = TurnkeyProvider(
config: TurnkeyConfig(
// ... your existing config ...
onSessionSelected: (session) {
// User authenticated — perform navigation or data preloads
navigatorKey.currentState?.pushReplacementNamed('/dashboard');
},
),
);
```
## Listening to provider updates
`TurnkeyProvider` is a `ChangeNotifier`, so you can attach listeners to respond to internal state changes (e.g., when user/wallets are fetched or when `authState` changes). This pattern is useful when you want to mirror provider data into local widget state.
Below is an example (adapted from the [demo app](https://github.com/tkhq/dart-sdk/tree/main/examples/flutter-demo-app)) that keeps a local `selectedWallet`/`selectedAccount` in sync with the provider:
```dart title=lib/screens/dashboard.dart (excerpt) theme={null}
class DashboardScreenState extends State {
Wallet? _selectedWallet;
v1WalletAccount? _selectedAccount;
late final TurnkeyProvider _turnkeyProvider;
late final VoidCallback _providerListener;
@override
void initState() {
super.initState();
// Capture provider once; no context in listener later.
_turnkeyProvider = Provider.of(context, listen: false);
_providerListener = _handleProviderUpdate;
_turnkeyProvider.addListener(_providerListener);
// Initialize local selections from provider.
_updateSelectedWalletFromProvider(_turnkeyProvider);
}
@override
void dispose() {
// Always remove listeners to avoid calling setState on a disposed widget.
_turnkeyProvider.removeListener(_providerListener);
super.dispose();
}
void _handleProviderUpdate() {
if (!context.mounted) return;
_updateSelectedWalletFromProvider(_turnkeyProvider);
}
void _updateSelectedWalletFromProvider(TurnkeyProvider provider) {
final wallets = provider.wallets;
final user = provider.user;
if (user == null || wallets == null || wallets.isEmpty) return;
if (wallets.first.accounts.isEmpty) return;
if (!context.mounted) return;
setState(() {
_selectedWallet = wallets.first;
_selectedAccount = wallets.first.accounts.first;
});
}
}
```
> **Tips**
>
> * Use `addListener/removeListener` for one-off reactions to state changes.
> * Use `Consumer`, `Selector`, or `context.select` when you want automatic rebuilds based on specific slices of provider state.
> * Avoid calling `setState` inside your listener after the widget is disposed — always guard with `if (!mounted) return;` or `if (!context.mounted) return;`.
## Customize sub-organization creation
Need to configure default user names, passkey names, wallet creations or anything sub-org related? You can learn more about customizing the sub-orgs you create in the [Sub-Organization Customization](/solutions/embedded-wallets/integration-guide/flutter/sub-organization-customization).
Follow the guides below to learn how to set up email and SMS authentication, passkey authentication, and social logins in your Flutter app.