Agent Skills: Building Beautiful Expo Apps with Gluestack UI

This document defines the skill set and operational guidelines for AI agents working on this project. The primary goal is to build high-quality, visually appealing mobile applications using Expo and gluestack-ui.

1. Technology Stack & Environment

• Framework: React Native (via Expo)
• UI Library: gluestack-ui
• Language: TypeScript (Preferred)
• Navigation: Expo Router (Standard for modern Expo apps)

2. Project Initialization Skills

When starting a new project or setting up the environment, the agent must follow these steps:

A. Create Expo Project

Use the latest Expo template:

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

B. Install gluestack-ui

Follow the official installation guide to integrate gluestack-ui:

1. Initialize gluestack-ui:

``bash npx gluestack-ui init ` - This command installs dependencies and adds the GluestackUIProvider. - It sets up the theme configuration. - It creates a components` folder for your UI components.

1. Wrap Application Root:

Ensure the root layout (e.g., app/_layout.tsx or App.tsx) is wrapped with the provider: ```tsx import { GluestackUIProvider } from "@/components/ui/gluestack-ui-provider"; import "@/global.css"; // If using NativeWind or global styles

export default function Layout() { return ( <GluestackUIProvider> <Slot /> {/ or your main app content /} </GluestackUIProvider> ); } ```

3. Component Management Skills

gluestack-ui is unstyled by default and headless, meaning you add components as you need them.

A. Adding Components

NEVER try to import a component that hasn't been added to the project. Always check the components/ui directory first.

To add a new component (e.g., Button, Box, Text):

npx gluestack-ui add [component-name]
# Example:
npx gluestack-ui add button box text

Agent Note: If a user asks for a UI element, identify the corresponding gluestack component, run the add command if it's missing, and then implement it.

B. Common Components & Usage

• Layout: Use Box, VStack, HStack, Center for layout instead of raw View styles.

``tsx <VStack space="md" reversed={false}> <Box className="w-20 h-20 bg-primary-500" /> </VStack> ``

• Typography: Use Text and Heading with size props.
• Interactivity: Use Button, Pressable, Link.

4. UI/UX Design & Styling Skills

A. Theming & Tokens

• Utilize the gluestack-ui tokens for spacing, colors, and typography to ensure consistency.
• Avoid hardcoded pixel values for margins/padding; use tokens (e.g., $2, $4, md, lg).

B. Responsive Design

• gluestack-ui supports responsive props.
• Example: <Box w="$full" md-w="$1/2"> (Full width on mobile, half width on medium screens/tablets).

C. "Beautiful" UI Principles

• Whitespace: Use ample padding and margin (via space prop in stacks or padding props).
• Hierarchy: Use font weights and colors to establish visual hierarchy.
• Feedback: Ensure interactive elements have hover/pressed states (gluestack handles this by default, but customization is possible).

5. Advanced Development Patterns

A. State Management

• Global State: Use Zustand for lightweight global state (e.g., user session, theme settings).

- Why: Minimal boilerplate, easy to use with hooks.

• Server State: Use TanStack Query (React Query) for data fetching.

- Why: Handles caching, loading states, and refetching automatically.

B. Form Handling

• Use React Hook Form controlled by Zod schema validation.

- Why: Performance (minimizes re-renders) and type safety. ``tsx import { useForm, Controller } from "react-hook-form"; import { zodResolver } from "@hookform/resolvers/zod"; // ... define z.object schema ... ``

C. Iconography

• Use Lucide Icons (lucide-react-native).
• Gluestack-ui integrates well with Lucide.

``tsx import { Camera } from "lucide-react-native"; import { Icon } from "@/components/ui/icon"; // Usage: <Icon as={Camera} size="md" /> ``

D. Navigation (Expo Router)

• Structure:

- app/_layout.tsx: Root provider setup (gluestack, query client). - app/(tabs): For tab-based navigation. - app/[id].tsx: For dynamic routes.

• Linking: Use Link from expo-router for web-compatible navigation.

6. Coding Best Practices for Agents

1. File Structure:

- Keep screens in app/ (if using Expo Router). - Keep reusable UI components in components/. - Keep business logic/hooks in hooks/ or utils/.

1. Code Style:

- Use functional components. - Use Hooks (useState, useEffect) appropriately. - Type Safety: strict TypeScript usage. Define interfaces for props.

1. Error Handling:

- When running commands (like npx gluestack-ui add), if they fail, analyze the error (e.g., missing peer dependencies) and fix it before proceeding.

1. Dependency Management:

- Expo Compatibility First: Always prioritize installing packages compatible with the latest Expo SDK. - Use npx expo install [package-name] instead of npm install or yarn add when possible, as this ensures the installed version is compatible with the project's Expo SDK version.

7. Workflow Checklist

When assigned a task to build a screen:

1. [ ] Analyze requirements.
2. [ ] Identify necessary UI components (e.g., Card, Avatar, Button).
3. [ ] Check if components exist in components/ui; if not, run npx gluestack-ui add ....
4. [ ] Scaffold the screen using VStack/HStack for layout.
5. [ ] Apply styling using theme tokens.
6. [ ] Verify responsiveness.

8. External Agent Skills & Resources

To enhance capability, the agent should leverage established skill sets from industry leaders:

A. React Native Best Practices (Callstack)

• Repository: callstackincubator/agent-skills
• Focus: Performance optimization (re-renders, startup time), bundling, and native modules.
• Instruction: Consult these skills when optimizing app performance or debugging complex native issues.

B. Expo Official Skills

• Repository: expo/skills
• Focus: Best practices for building, deploying (EAS), and upgrading Expo applications.
• Instruction: Use these skills for:

- upgrading-expo: When moving between Expo SDK versions. - expo-deployment: For setting up EAS Build and Submit. - expo-app-design: General Expo app architecture guidance.