Flutter AI UI Skill 🎨

Design intelligence for Flutter — turn any AI coding assistant into a Flutter UI expert.

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Overview

This skill provides comprehensive design intelligence for building and refining Flutter applications. It combines curated Flutter-specific best practices with professional UI/UX heuristics to produce beautiful, accessible, performant, and maintainable mobile interfaces.

When does this skill activate?

The skill activates automatically when you:

• Request UI/UX work in a Flutter project
• Ask to build, create, design, or improve any screen or component
• Use the /flutter-ai-ui slash command (Kiro, Copilot, Roo Code)

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How to Use This Skill

Step 1 – Gather Context

Before writing a single line of code, understand:

• App domain: healthcare, fintech, e-commerce, social, productivity, etc.
• Target audience: age group, technical literacy, accessibility needs
• Brand personality: playful, professional, minimal, bold, luxurious, warm
• Platform priorities: Android-first, iOS-first, cross-platform + web
• Color & font preferences: any existing assets or brand guidelines

Step 2 – Generate a Design System

Use data/flutter_colors.csv to choose your primary, secondary, surface and error palette based on category. Use data/flutter_typography.csv to pick a font-pairing that matches the app mood. Then generate a AppTheme class:

// Example — do NOT hardcode colours across widgets
final theme = ThemeData(
  useMaterial3: true,
  colorScheme: ColorScheme.fromSeed(
    seedColor: const Color(0xFF2563EB),
    brightness: Brightness.light,
  ),
  textTheme: GoogleFonts.poppinsTextTheme(),
);

Step 3 – Apply Flutter Design Guidelines

Consult data/stacks/flutter_guidelines.csv before implementing any component. Run the keyword search tool to find relevant dos & don'ts:

python scripts/search_guidelines.py --keyword "animation"
python scripts/search_guidelines.py --category "accessibility"
python scripts/search_guidelines.py --severity "critical"

Step 4 – Scaffold or Analyse

New project:

python scripts/create_flutter_project.py --name my_app --template material3
python scripts/create_flutter_project.py --name my_app --template cupertino
python scripts/create_flutter_project.py --name my_app --template adaptive

Existing project:

python scripts/analyse_flutter_project.py --path path/to/project
python scripts/analyse_flutter_project.py --path path/to/project --fix-suggestions

Step 5 – Pre-Delivery Checklist

Before handing off any UI work, verify:

✅ Accessibility

• All images have semantic labels or excludeFromSemantics: true for decorative ones
• Interactive elements have Tooltip or Semantics(label: ...)
• Color contrast meets WCAG AA (4.5:1 for text, 3:1 for UI components)
• Dynamic text scaling works — wrap with MediaQuery.textScalerOf
• FocusTraversalGroup and onKey keyboard navigation for desktop/web

✅ Responsiveness

• LayoutBuilder or AdaptiveLayout used for breakpoints
• Orientation not locked unless specifically required
• Content scrollable on small screens — never overflow
• Safe area respected with SafeArea widget

✅ Theming

• ThemeData with ColorScheme — no hardcoded hex colors in widgets
• darkTheme provided in MaterialApp
• Dynamic color (DynamicColorBuilder) supported where possible
• Custom fonts loaded via pubspec.yaml or google_fonts

✅ Performance

• const constructors everywhere possible
• ListView.builder / GridView.builder for long lists
• RepaintBoundary around heavy or animated widgets
• Images loaded via cached_network_image
• Build methods < 50 lines; heavy logic extracted to helpers

✅ Navigation & State

• Declarative routing via GoRouter (preferred) or Navigator 2.0
• PopScope handles Android predictive back gesture
• State management chosen and applied consistently (Riverpod / Bloc / Provider)
• Providers/Notifiers disposed correctly

✅ Code Quality

• Widgets extracted into separate files once > 80 lines
• No setState called inside build()
• No BuildContext stored across async gaps without checking mounted
• Widget tests cover critical UI flows

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Design Principles — Flutter Edition

1. Material 3 First

Always use useMaterial3: true. Leverage ColorScheme, Typography, NavigationBar, Card, FilledButton, ElevatedButton, InputDecoration with Material 3 defaults. Avoid overriding M3 tokens unnecessarily.

2. Adaptive, Not Responsive Only

Flutter runs on mobile, tablet, web, and desktop. Use AdaptiveLayout or LayoutBuilder with breakpoints:

• Mobile: < 600px
• Tablet: 600px – 1200px
• Desktop: > 1200px

3. Animation as Communication

Animations should communicate state changes, not just look pretty.

• Use AnimatedContainer, AnimatedOpacity, AnimatedSwitcher for implicit animations
• Use AnimationController + Tween for explicit control
• Use Hero for shared element transitions
• Keep durations between 150ms–400ms; 300ms is the sweet spot
• Use Curves.easeInOut by default; Curves.elasticOut for playful UIs

4. Elevation & Depth

Material 3 uses tonal elevation (color-based), not shadow-based by default. Use elevation with surfaceTintColor for cards. Use BoxShadow sparingly and consistently — define shadow tokens in your theme.

5. Typography Hierarchy

Always define a complete TextTheme:

• displayLarge/Medium/Small — Hero sections, splash screens
• headlineLarge/Medium/Small — Page and section titles
• titleLarge/Medium/Small — Card titles, list items, dialogs
• bodyLarge/Medium/Small — Body copy, descriptions
• labelLarge/Medium/Small — Buttons, tabs, chips

6. Spacing System

Use an 8-point spacing grid. Define constants:

class AppSpacing {
  static const double xs = 4;
  static const double sm = 8;
  static const double md = 16;
  static const double lg = 24;
  static const double xl = 32;
  static const double xxl = 48;
}

7. Color Token System

Never use raw hex in widgets. Use semantic tokens:

// ✅ Correct
color: Theme.of(context).colorScheme.primary

// ❌ Wrong
color: const Color(0xFF2563EB)

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UI Style Catalog

The following Flutter-specific UI styles are supported. Reference these when asked to build in a particular aesthetic:

Style	Description	Key Widgets & Techniques
Material 3 Clean	Google's latest design language, tonal color, gentle curves	FilledButton, Card, NavigationBar, ColorScheme.fromSeed
Cupertino Native	iOS-native look and feel	CupertinoApp, CupertinoNavigationBar, CupertinoButton
Glassmorphism	Frosted glass, blur, translucency	BackdropFilter, ImageFilter.blur, gradient overlays
Neumorphism	Soft embossed shadows, monochromatic depth	Layered BoxShadow with light/dark offset
Dark Neon	Dark background with glowing neon accents	Custom ColorScheme, BoxShadow with colored spread
Minimal Flat	Ultra-clean, plenty of whitespace, subtle borders	Container, Divider, precise typography
Claymorphism	Soft, pillowy 3D-like components	Large border radius, colored shadow, pastel palette
Brutalist	Raw, high-contrast, bold typography	Borders, monochrome, loud text, tight spacing
Gradient Premium	Layered gradients, depth and richness	LinearGradient, RadialGradient, ShaderMask
Organic Biophilic	Natural forms, earthy colors, soft curves	Custom clip paths, earth tones, organic shapes
Retro/Y2K	Nostalgic, pixel-inspired, bold colors	Custom painters, chunky UI, high saturation
Enterprise Dark	Professional dark dashboard aesthetic	Dark surface colors, data-dense layout, subtle dividers

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Flutter-Specific Component Blueprints

Bottom Navigation

// Prefer NavigationBar (M3) over BottomNavigationBar
NavigationBar(
  destinations: const [
    NavigationDestination(icon: Icon(Icons.home), label: 'Home'),
    NavigationDestination(icon: Icon(Icons.search), label: 'Search'),
  ],
  selectedIndex: _selectedIndex,
  onDestinationSelected: (i) => setState(() => _selectedIndex = i),
)

Loading States

// Use Shimmer loading — never show empty containers
Shimmer.fromColors(
  baseColor: Colors.grey.shade300,
  highlightColor: Colors.grey.shade100,
  child: Container(height: 80, color: Colors.white),
)

Error States

// Always handle error states visually
ErrorStateWidget(
  icon: Icons.cloud_off,
  title: 'Something went wrong',
  subtitle: error.toString(),
  onRetry: () => ref.refresh(myProvider),
)

Pull-to-Refresh

RefreshIndicator.adaptive( // Use adaptive for iOS/Android
  onRefresh: () async => ref.refresh(myProvider),
  child: ListView.builder(...),
)

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Supported AI Platforms

This skill works with all major AI coding assistants:

Platform	Activation Mode	Setup Location
Antigravity	Skill auto-activation	.agents/skills/
Claude Code	CLAUDE.md / skill	.claude/
Cursor	Rules file	.cursor/rules/
Windsurf	Rules file	.windsurf/rules/
GitHub Copilot	Slash command	.github/copilot-instructions.md
Gemini CLI	GEMINI.md	GEMINI.md
Kiro	Spec/hook	.kiro/
Roo Code	Rules	.roo/
OpenCode	Rules	opencode.json
Continue	Config	.continue/rules/
Zed	Rules	.zed/settings.json

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File Structure Reference

flutter-ai-ui-skill/
├── SKILL.md                          ← You are here (AI reads this)
├── README.md                         ← Human-facing documentation
├── data/
│   ├── flutter_colors.csv            ← 30+ Flutter app-type palettes
│   ├── flutter_typography.csv        ← 15 Google Fonts pairings
│   └── stacks/
│       └── flutter_guidelines.csv    ← 120+ Flutter UI guidelines
├── scripts/
│   ├── analyse_flutter_project.py    ← Project audit tool
│   ├── search_guidelines.py          ← Guideline keyword search
│   └── create_flutter_project.py     ← Project scaffolder
└── templates/
    ├── material3/                    ← Material 3 starter
    ├── cupertino/                    ← Cupertino/iOS starter
    └── adaptive/                     ← Adaptive multi-platform starter

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Quick Reference: Top 20 Flutter UI Rules

#	Rule	Severity
1	Use const constructors for immutable widgets	🔴 Critical
2	Never hardcode colors — use Theme.of(context).colorScheme	🔴 Critical
3	Keep build() methods under 50 lines	🔴 Critical
4	Use ListView.builder for any list > 10 items	🔴 Critical
5	Provide darkTheme in MaterialApp	🟠 High
6	Add Semantics labels to all interactive/image widgets	🟠 High
7	Use RepaintBoundary around animated widgets	🟠 High
8	Check mounted before using BuildContext after async	🟠 High
9	Use cached_network_image for all network images	🟠 High
10	Use GoRouter for declarative routing	🟡 Medium
11	Prefer AnimatedContainer over explicit animations for simple transitions	🟡 Medium
12	Use LayoutBuilder for responsive breakpoints	🟡 Medium
13	Extract reusable widgets into separate files	🟡 Medium
14	Use SafeArea for content near edges	🟡 Medium
15	Prefer Flexible/Expanded over fixed sizes in rows/columns	🟡 Medium
16	Use Hero widget for page transition shared elements	🟢 Low
17	Apply TextScaler support for accessibility	🟢 Low
18	Use PopScope for Android back gesture	🟢 Low
19	Prefer SelectableText for copyable content	🟢 Low
20	Use AdaptiveLayout from flutter_adaptive_scaffold for multi-platform	🟢 Low

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Flutter AI UI Skill — Built with ❤️ for the Flutter community. See README.md for installation instructions and full documentation.