Flutter Guide

Applies to: Flutter 3.x, Dart 3.x, Mobile (iOS/Android), Web, Desktop

Core Principles

1. Widget Composition: Build complex UIs by composing small, focused widgets
2. Declarative UI: Describe what the UI should look like; Flutter handles rendering
3. Immutable Widgets: Widgets are configuration objects; state lives in State classes or providers
4. Single Codebase: One Dart codebase targets iOS, Android, Web, macOS, Windows, Linux
5. Riverpod for State: Use Riverpod as the primary state management solution
6. Material 3 First: Default to Material 3 design system with useMaterial3: true

Guardrails

Widget Rules

• Keep widget build methods under 50 lines (extract sub-widgets)
• Prefer const constructors for all stateless widgets