react-server-components-framework

# React Server Components Framework

## Overview

React Server Components (RSC) enable server-first rendering with client-side interactivity. This skill covers Next.js 16 App Router patterns, Server Components, Server Actions, and streaming.

**When to use this skill:**
- Building Next.js 16+ applications with the App Router
- Designing component boundaries (Server vs Client Components)
- Implementing data fetching with caching and revalidation
- Creating mutations with Server Actions
- Optimizing performance with streaming and Suspense

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## Quick Reference

### Server vs Client Components

| Feature | Server Component | Client Component |
|---------|-----------------|------------------|
| Directive | None (default) | `'use client'` |
| Async/await | Yes | No |
| Hooks | No | Yes |
| Browser APIs | No | Yes |
| Database access | Yes | No |
| Client JS bundle | Zero | Ships to client |

**Key Rule**: Server Components can render Client Components, but Client Components cannot directly import Server Components (use `children` prop instead).

### Data Fetching Quick Reference

**Next.js 16 Cache Components (Recommended):**

```tsx
import { cacheLife, cacheTag } from 'next/cache'

// Cached component with duration
async function CachedProducts() {
  'use cache'
  cacheLife('hours')
  cacheTag('products')
  return await db.product.findMany()
}

// Invalidate cache
import { revalidateTag } from 'next/cache'
revalidateTag('products')
```

**Legacy Fetch Options (Next.js 15):**

```tsx
// Static (cached indefinitely)
await fetch(url, { cache: 'force-cache' })

// Revalidate every 60 seconds
await fetch(url, { next: { revalidate: 60 } })

// Always fresh
await fetch(url, { cache: 'no-store' })

// Tag-based revalidation
await fetch(url, { next: { tags: ['posts'] } })
```

### Server Actions Quick Reference

```tsx
'use server'

export async function createPost(formData: FormData) {
  const title = formData.get('title') as string
  const post = await db.post.create({ data