Overview

Validation and quality enforcement for Expo React Native projects.

What This Buki Provides

Validation Hooks

• TypeScript Type Check: Runs TypeScript compiler to validate types in Expo projects
• Fast Validation: Provides quick feedback on type errors before commits
• Expo Project Detection: Validates only directories with app.json files

Skills

This buki provides the following skills:

• expo-config: Configuring Expo apps with app.json, app.config.js/ts, and EAS configuration including plugins, build settings, and environment variables
• expo-router: Implementing file-based routing with Expo Router including layouts, dynamic routes, navigation, and deep linking
• expo-modules: Working with Expo SDK modules for camera, location, notifications, file system, and other device APIs
• expo-updates: Implementing over-the-air (OTA) updates with Expo Updates for deploying changes without app store releases
• expo-build: Building and deploying Expo apps with EAS Build including development builds, production builds, and app store submission

Installation

Install via the Han marketplace:

npx @thebushidocollective/han install

Or install manually:

claude plugin marketplace add thebushidocollective/han
claude plugin install buki-expo@han

Usage

Once installed, this buki automatically validates your Expo code:

• When you finish a conversation with Claude Code
• When Claude Code agents complete their work
• Before commits (when combined with git hooks)

The validation runs tsc --noEmit to check for TypeScript type errors without generating output files.

Requirements

• Expo SDK 50 or higher
• TypeScript 5.0 or higher
• Node.js 18 or higher

Why Expo?

Expo is a framework and platform for React Native that makes mobile development faster and easier:

• Managed Workflow: Build apps without touching native code
• EAS (Expo Application Services): Cloud build, updates, and submission
• Expo Router: File-based routing system
• Rich SDK: 50+ modules for device features (camera, location, etc.)
• OTA Updates: Deploy updates instantly without app store review
• Universal Apps: Share code across iOS, Android, and web
• Developer Experience: Fast refresh, debugging tools, and documentation

Features Covered by Skills

Configuration (app.json/app.config.ts)

• App metadata and settings
• Platform-specific configuration
• Plugin system
• Environment variables
• Build profiles
• Deep linking setup

Expo Router

• File-based routing
• Stack, tab, and drawer navigation
• Dynamic routes with parameters
• Layouts and nested routes
• Route groups
• Authentication flows
• Modal routes
• Type-safe navigation

Expo Modules (SDK)

• Camera and image picker
• Location and maps
• Push notifications
• File system and storage
• Secure storage
• Device information
• Background tasks
• Sharing and permissions

OTA Updates

• Automatic update checking
• Manual update triggers
• Update channels
• Runtime versions
• Silent updates
• Update UI patterns

EAS Build

• Development builds
• Preview and production builds
• Environment configuration
• Secrets management
• Version management
• App store submission
• Build monitoring

Quick Start Examples

Create New Expo App

npx create-expo-app@latest my-app
cd my-app

Basic Expo Router App

// app/_layout.tsx
import { Stack } from 'expo-router';

export default function RootLayout() {
  return <Stack />;
}

// app/index.tsx
import { Link } from 'expo-router';
import { View, Text } from 'react-native';

export default function Home() {
  return (
    <View>
      <Text>Home Screen</Text>
      <Link href="/details">Go to Details</Link>
    </View>
  );
}

// app/details.tsx
export default function Details() {
  return (
    <View>
      <Text>Details Screen</Text>
    </View>
  );
}

Using Expo Modules

import { Camera } from 'expo-camera';
import * as Location from 'expo-location';
import * as Notifications from 'expo-notifications';

// Request permissions and use modules
const [cameraPermission] = Camera.useCameraPermissions();

Configure for Production

// app.config.ts
export default {
  name: 'MyApp',
  slug: 'my-app',
  version: '1.0.0',
  extra: {
    apiUrl: process.env.API_URL,
  },
  plugins: [
    'expo-router',
    'expo-camera',
    'expo-location',
  ],
};

Build with EAS

# Install EAS CLI
npm install -g eas-cli

# Login
eas login

# Configure project
eas build:configure

# Build for iOS
eas build --platform ios --profile production

# Build for Android
eas build --platform android --profile production

Project Structure

Recommended structure for Expo apps with Expo Router:

my-app/
├── app/                  # Routes (file-based routing)
│   ├── (tabs)/          # Tab navigation group
│   │   ├── _layout.tsx
│   │   ├── index.tsx
│   │   └── profile.tsx
│   ├── _layout.tsx      # Root layout
│   └── index.tsx        # Home route
├── components/          # Reusable components
├── hooks/               # Custom hooks
├── utils/               # Utility functions
├── assets/              # Images, fonts, etc.
├── app.json             # Expo configuration
├── eas.json             # EAS Build configuration
├── package.json
└── tsconfig.json

Common Expo Modules

Essential modules for most Expo apps:

• expo-router: File-based navigation
• expo-camera: Camera access
• expo-location: Location services
• expo-notifications: Push notifications
• expo-image-picker: Select images/videos
• expo-file-system: File operations
• expo-secure-store: Encrypted storage
• expo-constants: App and device info
• expo-linking: Deep linking
• expo-updates: OTA updates

Development Workflow

Typical Expo development workflow:

1. Development: npx expo start - Start dev server
2. Testing: Test on iOS Simulator, Android Emulator, or physical devices
3. Preview Build: eas build --profile preview - Internal testing
4. Production Build: eas build --profile production - App store release
5. OTA Updates: eas update - Deploy JS updates instantly

Testing

Expo apps can be tested with:

• Jest: Unit testing (included by default)
• Detox: End-to-end testing
• Expo Go: Quick testing without builds
• Development Builds: Test with native code

Expo vs Bare React Native

Expo provides:

• Managed workflow (no native code needed)
• EAS cloud services
• Rich module ecosystem
• Faster development
• OTA updates out of the box

Choose bare React Native when you need:

• Custom native modules not in Expo
• Full control over native code
• Specific third-party native libraries

Contributing

See CONTRIBUTING.md for guidelines.

License

MIT License - See LICENSE for details.