Agent skill
react-web
Modern React 19+ development with Server Components, Actions, hooks, TypeScript integration, and performance optimization. Use when building React web applications, implementing Server Components, using Actions for form handling, working with new hooks (use, useActionState, useOptimistic, useFormStatus), setting up React projects with Vite or Next.js, or optimizing React performance.
Install this agent skill to your Project
npx add-skill https://github.com/majiayu000/claude-skill-registry/tree/main/skills/design/react-web-ibutters-claudecodeplugins
SKILL.md
React Web Development (React 19+)
Build modern, performant React applications using React 19+ features.
Core Patterns
Function Components with TypeScript
interface ButtonProps {
variant?: 'primary' | 'secondary';
children: React.ReactNode;
onClick?: () => void;
}
export function Button({ variant = 'primary', children, onClick }: ButtonProps) {
return (
<button className={`btn btn-${variant}`} onClick={onClick}>
{children}
</button>
);
}
Server Components (Default in React 19)
Server Components render on the server, reducing client JavaScript:
// app/posts/page.tsx - Server Component (default)
async function PostList() {
const posts = await db.posts.findMany();
return (
<ul>
{posts.map(post => <li key={post.id}>{post.title}</li>)}
</ul>
);
}
Client Components
Mark interactive components with 'use client':
'use client';
import { useState } from 'react';
export function Counter() {
const [count, setCount] = useState(0);
return <button onClick={() => setCount(c => c + 1)}>{count}</button>;
}
React 19 Features
Actions & useActionState
Replace manual form handling with Actions:
'use client';
import { useActionState } from 'react';
async function submitForm(prev: State, formData: FormData) {
'use server';
const name = formData.get('name');
await db.users.create({ name });
return { success: true };
}
function Form() {
const [state, action, pending] = useActionState(submitForm, { success: false });
return (
<form action={action}>
<input name="name" />
<button disabled={pending}>{pending ? 'Saving...' : 'Save'}</button>
</form>
);
}
use() Hook for Promises & Context
import { use } from 'react';
function UserProfile({ userPromise }) {
const user = use(userPromise); // Suspends until resolved
return <div>{user.name}</div>;
}
function ThemeButton() {
const theme = use(ThemeContext); // Read context conditionally
return <button style={{ color: theme.primary }}>Click</button>;
}
useOptimistic for Instant UI Updates
'use client';
import { useOptimistic } from 'react';
function TodoList({ todos, addTodo }) {
const [optimisticTodos, addOptimisticTodo] = useOptimistic(
todos,
(state, newTodo) => [...state, { ...newTodo, pending: true }]
);
async function handleAdd(formData: FormData) {
const text = formData.get('text');
addOptimisticTodo({ text, id: Date.now() });
await addTodo(text);
}
return (
<form action={handleAdd}>
<input name="text" />
<ul>
{optimisticTodos.map(todo => (
<li key={todo.id} style={{ opacity: todo.pending ? 0.5 : 1 }}>
{todo.text}
</li>
))}
</ul>
</form>
);
}
useFormStatus for Form State
'use client';
import { useFormStatus } from 'react-dom';
function SubmitButton() {
const { pending } = useFormStatus();
return <button disabled={pending}>{pending ? 'Submitting...' : 'Submit'}</button>;
}
Project Structure
src/
├── app/ # App Router (Next.js) or routes
├── components/
│ ├── ui/ # Reusable UI primitives
│ ├── features/ # Feature-specific components
│ └── layouts/ # Layout components
├── hooks/ # Custom hooks
├── lib/ # Utilities, API clients
├── types/ # TypeScript types
└── styles/ # Global styles, tokens
Custom Hooks Pattern
function useAsync<T>(asyncFn: () => Promise<T>, deps: unknown[]) {
const [state, setState] = useState<{
data: T | null;
loading: boolean;
error: Error | null;
}>({ data: null, loading: true, error: null });
useEffect(() => {
setState(s => ({ ...s, loading: true }));
asyncFn()
.then(data => setState({ data, loading: false, error: null }))
.catch(error => setState({ data: null, loading: false, error }));
}, deps);
return state;
}
Performance Guidelines
- Let React Compiler optimize - React 19's compiler auto-memoizes; avoid manual useMemo/useCallback unless profiling shows need
- Use Server Components - Default to server rendering, add 'use client' only for interactivity
- Lazy load routes - Use
React.lazy()and Suspense for code splitting - Avoid prop drilling - Use Context or composition patterns
Related Skills
- Atomic Design: Component hierarchy patterns → See
references/atomic-integration.md - CSS Tokens: Styling with design tokens → See
references/styling-patterns.md - Storybook: Component documentation → See
references/storybook-setup.md
Recommended Agent Skills
Expand your agent's capabilities with these related and highly-rated skills.
agent-ops-spec
Manage specification documents in .agent/specs/. Use when user provides requirements, acceptance criteria, or feature descriptions that need to be tracked and validated against implementation.
agent-ops-state
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agent-ops-spec
Manage specification documents in .agent/specs/. Use when user provides requirements, acceptance criteria, or feature descriptions that need to be tracked and validated against implementation.
agent-ops-testing
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agent-ops-testing
Test strategy, execution, and coverage analysis. Use when designing tests, running test suites, or analyzing test results beyond baseline checks.
agent-ops-state
Maintain .agent state files. Use at session start, after meaningful steps, and before concluding: read/update constitution/memory/focus/issues/baseline consistently.
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