Starter Flutter App

Create a Flutter application initialized for use with the atSDK

1. Create a new Flutter app

First, generate a new Flutter app (replace at_app with the name of your application).

flutter create at_app
cd at_app

2. Add dependencies

Then add the following dependencies to your project:

flutter pub add at_client_mobile at_onboarding_flutter flutter_dotenv path_provider

3. Replace main.dart

Now copy the contents of main.dart from below into lib/main.dart into your project.

import 'dart:async';

import 'package:flutter/material.dart';
import 'package:at_onboarding_flutter/at_onboarding_flutter.dart';
import 'package:flutter_dotenv/flutter_dotenv.dart';
import 'package:path_provider/path_provider.dart'
    show getApplicationSupportDirectory;

import 'home_screen.dart';

Future<void> main() async {
  await dotenv.load();
  runApp(const MyApp());

Future<AtClientPreference> loadAtClientPreference() async {
  var dir = await getApplicationSupportDirectory();

  return AtClientPreference()
    ..rootDomain = ''
    ..namespace = dotenv.env['NAMESPACE']
    ..hiveStoragePath = dir.path
    ..commitLogPath = dir.path
    ..isLocalStoreRequired = true;
  // * By default, this configuration is suitable for most applications
  // * In advanced cases you may need to modify [AtClientPreference]
  // * Read more here:

class MyApp extends StatefulWidget {
  const MyApp({Key? key}) : super(key: key);
  MyAppState createState() => MyAppState();

class MyAppState extends State<MyApp> {
  // * load the AtClientPreference in the background
  Future<AtClientPreference> futurePreference = loadAtClientPreference();

  Widget build(BuildContext context) {
    return MaterialApp(
      // * The onboarding screen (first screen)
      home: Scaffold(
        appBar: AppBar(
          title: const Text('MyApp'),
        body: Builder(
          builder: (context) => Center(
            child: ElevatedButton(
              onPressed: () async {
                AtOnboardingResult onboardingResult =
                    await AtOnboarding.onboard(
                  context: context,
                  config: AtOnboardingConfig(
                    atClientPreference: await futurePreference,
                    rootEnvironment: RootEnvironment.Production,
                    domain: '',
                if (mounted) {
                  switch (onboardingResult.status) {
                    case AtOnboardingResultStatus.success:
                        MaterialPageRoute(builder: (_) => const HomeScreen()),
                    case AtOnboardingResultStatus.error:
                        const SnackBar(
                          content: Text('An error has occurred'),
                    case AtOnboardingResultStatus.cancel:
              child: const Text('Onboard an @sign'),

4. Add home_screen.dart

Create a second file in lib/ called home_screen.dart. Copy the contents of home_screen.dart from below into your project.

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

// * Once the onboarding process is completed you will be taken to this screen
class HomeScreen extends StatelessWidget {
  const HomeScreen({Key? key}) : super(key: key);

  Widget build(BuildContext context) {
    // * Getting the AtClientManager instance to use below
    AtClientManager atClientManager = AtClientManager.getInstance();
    // * Getting the AtClient instance to use below
    AtClient atClient = atClientManager.atClient;

    // * From this widget onwards, you are fully onboarded!
    // * You can use the AtClient instance to perform operations as the onboared atSign
    return Scaffold(
      appBar: AppBar(
        title: const Text('What\'s my current @sign?'),
      body: Center(
        child: Column(children: [
          const Text('Successfully onboarded and navigated to FirstAppScreen'),

          // * Use the AtClient to get the current @sign
          Text('Current @sign: ${atClient.getCurrentAtSign()}')

5. Setup the .env file

5.a. gitignore the .env file

Add the following line to the top of .gitignore:


This will prevent accidentally uploading the secret values stored in .env to any git repositories associated with your app.

5.b. Add and populate the .env file

Create a new file in the root of the project (next to pubspec.yaml) called .env. Add the following lines to it:


These values should be populated with your unique app namespace, and registrar API key.

5.c. Register the .env file in pubspec.yaml

In pubspec.yaml there should be a flutter: key, under this key, we want to create and add .env the assets: list:

    - .env

6. Start developing!

Start your application with the following command:

flutter run

Now you are ready to begin developing!

Additional Notes


To authenticate an atSign, we will use at_onboarding_flutter. You can register an atSign through the registrar or through the widget in the app.

AtOnboardingResult onboardingResult = await AtOnboarding.onboard(
  context: context,
  config: AtOnboardingConfig(
    atClientPreference: futurePreference,
    rootEnvironment: RootEnvironment.Production,
    appAPIKey: dotenv.env['API_KEY'],
    domain: '',

To get an API key for your app you can get on by going to the Manage section of your atSign on the registrar website and then click Advanced Settings.

Other atPlatform Packages

View other packages from Atsign here

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