alien_signals 2.4.0

Alien Signals is a reactive state management library that brings the power of signals to Dart and Flutter applications.

🎊 Get Started Today!

import 'package:alien_signals/alien_signals.dart';

void main() {
  final count = signal(0);
  final doubled = computed((_) => count() * 2);
  final stop = effect(() {
    print('Count: ${count()}, Doubled: ${doubled()}');
  }); // Count: 0, Doubled: 0

  count.set(1); // Count: 1, Doubled: 2
  stop();
  count.set(2); // The stopped effect no longer runs.
}

Run the complete example with dart run example/main.dart.

🌟 What is Alien Signals?

Alien Signals is a reactive core for Dart built around a generic ReactiveSystem. It includes a high-performance signals preset and a small, ergonomic surface API. Inspired by StackBlitz's alien-signals, the Dart implementation provides:

• 🪶 Ultra Lightweight: Minimal overhead, maximum efficiency
• 🎯 Simple API: Intuitive signal(), computed(), and effect() functions
• 🔧 Production Ready: Battle-tested through comprehensive beta releases

🧭 Core Layers

• System: A reusable reactive graph and propagation engine (system).
• Preset: A complete signals implementation on top of the system (preset).
• Surface API: Convenience signal/computed/effect wrappers built on the preset.

🚀 Key Features

• Lazy Computed Values: Cache derived state until dependencies change
• Effect Cleanup: Release resources before re-running and on disposal
• Effect Scopes: Group effects and nested scopes under one disposal handle
• Batch Operations: Defer effects while applying multiple writes
• Flexible API: Use the surface directly or customize the preset and system

See the runnable recipes for each feature.

📦 Installation

Requires Dart 3.13 or later.

dart pub add alien_signals

📖 Documentation

• Guide: Layers (system/preset/surface) and core concepts. See docs/guide.md.
• API Reference: Generated documentation for all three public libraries. See docs/api.md.
• Recipes: Runnable examples, lifecycle rules, and common pitfalls. See docs/recipes.md.

AI agent skill

From your project, install the bundled alien-signals-reactivity skill to help your coding agent write reactive code, debug missed updates and cleanup, and build libraries on Alien Signals:

dart run skills@ get -p alien_signals

Select your coding agent when prompted. Try asking it to:

• Find why a signal update does not reach an effect.
• Add a reactive search that ignores outdated responses and stops on disposal.
• Build a .value wrapper while preserving tracking and cleanup.

🌍 Community & Ecosystem

Adoptions

• Solidart - Signals for Flutter inspired by SolidJS
• Oref - Magical reactive state management for Flutter
• flutter_compositions - Vue-inspired reactive building blocks for Flutter
• ZenBus - A high-performance, flexible event bus for Flutter applications
• ZenSignals - Signal-based state bridging Flutter's ValueNotifier and ValueListenable APIs
• alien_signals_translator - Reactive JSON-based localization with ICU message formatting for Flutter
• signal_router - Signal-based routing and navigation state for Dart and Flutter (alpha)

Growing Ecosystem

Join our thriving community of developers building reactive applications with Alien Signals!

📚 Resources

• API Documentation - Complete API reference
• Examples - Code examples and demos
• Migration Guide - Upgrade instructions