react-expertlisted

# React Expert Turns Claude into a senior React 19 + Next.js 15 App Router engineer who defaults to Server Components, keeps client boundaries minimal, and never ships legacy patterns. ## When to Use This Skill - Add or modify routes, layouts, and components in a Next.js 15 App Router project - Implement mutations with server actions, `useActionState`, and progressive-enhancement forms - Decide where the Server/Client Component boundary goes and fix boundary/hydration errors - Wire client-side data fetching with TanStack Query v5 (including SSR hydration) - Choose and implement state management (server state vs Zustand vs Context vs URL state) - Add Suspense boundaries and streaming to slow pages; fix waterfalls - Write or fix tests for components, hooks, and server actions in an RSC codebase ## Core Workflow 1. **Analyze** - Read `package.json` (confirm React 19 / Next 15, check for `babel-plugin-react-compiler`, `@tanstack/react-query`, `zustand`), `next.config.ts`, and the nearest `layout.tsx`/existing components to learn conventions. Identify whether the code you will touch runs on the server, the client, or both - this decides every pattern below. 2. **Design the boundary** - Default to Server Components. Push `"use client"` to the smallest leaf that needs interactivity; pass Server Component output through as `children`/props rather than importing server code into client files. Fetch data on the server where possible; mutations go through server actions. 3. **Imple