Flipt SDK

A lightweight client for consuming Flipt feature flag snapshots in Flutter/Dart applications. The SDK provides typed accessors, offline fallback, and optional persistent caching so you can toggle experiences without shipping a new build.

It's really hard to set value other then bool when using Flipt. So, I create this package that uses description as value of the flag. Because of that, it will not have the full features when comparing to the original package.

Features

• Typed helpers for bool, int, double, String, List, and Map flag values
• Optional persistent caching via SharedPreferences
• Periodic background refresh with configurable interval and timeout
• Entity and context support for server-side evaluations
• Works offline by falling back to cached data or local defaults

Getting started

1. Add the dependency to your Flutter project:

   flutter pub add flipt

2. Ensure you have a Flipt API token and know the namespace/environment you want to target.

Usage

Create a single Flipt instance and keep it alive for as long as you need to evaluate flags.

import 'package:flipt/flipt.dart';

Future<void> bootstrapFeatureFlags() async {
  final flipt = Flipt(
    host: 'feature-flags.example.com',
    token: 'your-api-token',
    namespace: 'production',
    environment: 'mobile-app',
    entityId: 'user-42',
    context: const {
      'app_version': '2.5.0',
      'platform': 'ios',
    },
    defaultValues: {
      'new_checkout_flow': false,
      'max_recommendations': 6,
      'api_base_url': 'https://api.example.com',
      'checkout_thresholds': const <String, Object>{
        'caution': 0.6,
        'critical': 0.9,
      },
      'supported_locales': const <String>['en', 'vi'],
    },
    storage: FliptSharedPreferencesStorage('Flipt'), // See more in example
    fetchInterval: const Duration(minutes: 15),
    timeout: const Duration(seconds: 5),
    shouldFetchFromRemote: () async {
      final connected = await Connectivity().checkConnectivity();
      return !connected.contains(ConnectivityResult.none);
    },
    isDebug: true,
  );

  await flipt.ensureInitialized;

  final newFlowEnabled =
      flipt.getBool('new_checkout_flow', defaultValue: false);
  final maxRecommendations =
      flipt.getInt('max_recommendations', defaultValue: 3);
  final checkoutThresholds = flipt.getMap<double>('checkout_thresholds');
  final supportedLocales = flipt.getList<String>('supported_locales');

  // Use the values in your UI/business logic...

  flipt.dispose();
}

See example for a more complete sample.

Testing

This package ships with unit tests that cover the typed value helpers. You can run them locally with:

flutter test

Additional information

• Please remember that the package uses description act as value of the flag so it will not have the full features as the original one.
• Issues & feature requests: GitHub Issues
• Follow the official Flipt documentation for advanced configuration: https://www.flipt.io/docs