React Server Components Framework

Overview

React Server Components (RSC) enable server-first rendering with client-side interactivity. This skill covers Next.js 16.2 LTS App Router patterns, Server Components, Server Actions, and streaming.

Next.js 16.2.6 / React 19.2.6 (security release, May 2026) — Turbopack is the default bundler (no --turbo flag needed), Server Fast Refresh is on by default, and the new cacheComponents config flag replaces the legacy experimental_ppr escape hatch. For AI-agent debugging Next.js ships Next DevTools MCP — wire npx -y next-devtools-mcp@latest into .mcp.json (it connects via the dev server's /_next/mcp endpoint) to inspect render trees and cache boundaries mid-session.

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):

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

// Default — shared across all users (public CDN-cached)
async function CachedProducts() {
  'use cache'
  cacheLife('hours')
  cacheTag('products')
  return await db.product.findMany()
}

// Remote variant (16.2+) — always served from the edge/CDN, never rendered
// inline on the origin. Best for static product listings, marketing content.
async function MarketingHero() {
  'use cache: remote'
  cacheLife('days')
  return <Hero />
}

// Private variant (16.2+) — cached per-user session. Never shared across
// users. Use for personalized dashboards with expensive computation.
async function UserDashboard({ userId }: { userId: string }) {
  'use cache: private'
  cacheLife('minutes')
  cacheTag(`user:${userId}`)
  return await loadDashboard(userId)
}

// Invalidate cache — v16 requires a cacheLife profile as the 2nd arg
import { revalidateTag } from 'next/cache'
revalidateTag('products', 'max') // or updateTag('products') for read-your-writes

Enable via next.config.ts:

import type { NextConfig } from 'next'
const config: NextConfig = {
  cacheComponents: true,  // 16.2+ — replaces experimental_ppr flag
}
export default config

Legacy Fetch Options (Next.js 15):

// 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

'use server'

export async function createPost(formData: FormData) {
  const title = formData.get('title') as string
  const post = await db.post.create({ data: { title } })
  revalidatePath('/posts')
  redirect("/posts/" + post.id)
}

Async Params/SearchParams (Next.js 16)

Route parameters and search parameters are now Promises that must be awaited:

// app/posts/[slug]/page.tsx
export default async function PostPage({
  params,
  searchParams,
}: {
  params: Promise<{ slug: string }>
  searchParams: Promise<{ page?: string }>
}) {
  const { slug } = await params
  const { page } = await searchParams
  return <Post slug={slug} page={page} />
}

Note: Also applies to layout.tsx, generateMetadata(), and route handlers. Complete migration guide: first-party next-upgrade / vercel:next-upgrade skill. House scars: Read("${CLAUDE_PLUGIN_ROOT}/skills/react-server-components-framework/references/ork-delta.md").

Dev Server (Next.js 16.2 LTS)

• Turbopack default — next dev and next build run Turbopack without any flag. Pass --webpack only when forced (legacy plugin).
• Server Fast Refresh — Server Components hot-reload on save without losing client state. No extra config; it's on by default in 16.2.
• Next DevTools MCP — register npx -y next-devtools-mcp@latest in .mcp.json; it attaches to the running dev server over the /_next/mcp endpoint and exposes RSC payloads and cache boundaries to an MCP client. Designed for AI agents that need to inspect render trees mid-session without screenshotting. (There is no next-browser binary.)

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References

Load on demand with Read("${CLAUDE_PLUGIN_ROOT}/skills/react-server-components-framework/references/<file>"):

File	Content
ork-delta.md	House rules and scars: fabricated-API corrections from PR #2143, React 19 house conventions (2026-07-31 distillation)
tanstack-router-patterns.md	React 19 features without Next.js, route-based data fetching, client-rendered app patterns
capability-details.md	Keyword and problem-mapping metadata for all 12 RSC capabilities

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Upstream coverage (do not restate)

Vendor tutorials for these topics live in first-party skills and docs. This skill keeps only floors, scars, and house decisions (references/ork-delta.md).

Topic	First-party source
Server Components fundamentals (async components, data fetching, route segment config, generateStaticParams, error handling)	next-best-practices / vercel:nextjs skill; nextjs.org/docs
Client Components, 'use client', hydration, client-only rendering	next-best-practices / vercel:nextjs skill
Server/Client boundary and composition patterns, serializable props	next-best-practices / vercel:nextjs skill; vercel-composition-patterns
Data fetching and caching (fetch cache options, revalidate, tags)	next-best-practices / vercel:nextjs skill
Streaming SSR, Suspense boundaries, loading.tsx, skeleton states	vercel:nextjs skill (streaming)
Server Actions, progressive enhancement, useActionState forms, Zod validation	vercel:nextjs skill (Server Actions)
Advanced routing (parallel, intercepting, route groups, dynamic and catch-all)	vercel:nextjs skill (routing)
Pages Router to App Router migration	next-upgrade / vercel:next-upgrade skill
Next.js 16 upgrade, breaking changes, codemods	next-upgrade / vercel:next-upgrade skill
Cache Components: use cache, cacheLife, cacheTag, updateTag, PPR	next-cache-components / vercel:next-cache-components skill
React 19 core APIs (useActionState, useFormStatus, useOptimistic, use(), ref as prop)	context7: /vercel/next.js + react.dev (query-docs)
RSC implementation and deployment checklist	next-best-practices skill

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Best Practices Summary

Component Boundaries

• Keep Client Components at the edges (leaves) of the component tree
• Use Server Components by default
• Extract minimal interactive parts to Client Components
• Pass Server Components as children to Client Components

Data Fetching

• Fetch data in Server Components close to where it's used
• Use parallel fetching (Promise.all) for independent data
• Set appropriate cache and revalidate options
• Use generateStaticParams for static routes

Performance

• Use Suspense boundaries for streaming
• Implement loading.tsx for instant loading states
• Enable PPR for static/dynamic mix
• Use route segment config to control rendering mode

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Templates

• scripts/server-component-template.tsx - Basic async Server Component with data fetching
• scripts/client-component-template.tsx - Interactive Client Component with hooks
• scripts/server-action-template.ts - Server Action with validation and revalidation
• scripts/create-server-component.md - Command-style scaffold; kept as the script-invocation contract exercised by tests/skills/scripts/

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Troubleshooting

Error	Fix
"You're importing a component that needs useState"	Add 'use client' directive
"async/await is not valid in non-async Server Components"	Add async to function declaration
"Cannot use Server Component inside Client Component"	Pass Server Component as children prop
"Hydration mismatch"	Use 'use client' for Date.now(), Math.random(), browser APIs
"params is not defined" or params returning Promise	Add await before params (Next.js 16 breaking change)
"experimental_ppr is not a valid export"	Use Cache Components with "use cache" directive instead
"cookies/headers is not a function"	Add await before cookies() or headers() (Next.js 16)

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Resources

• Next.js 16 Documentation
• React 19.2 Blog Post
• React Server Components RFC
• App Router Migration Guide

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Related Skills

After mastering React Server Components:

1. Streaming API Patterns - Real-time data patterns
2. Type Safety & Validation - tRPC integration
3. Edge Computing Patterns - Global deployment
4. Performance Optimization - Core Web Vitals

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Capability Details

Keyword and problem-mapping metadata for each RSC capability (react-19-patterns, use-hook-suspense, optimistic-updates-async, rsc-patterns, server-actions, data-fetching, streaming-ssr, caching, cache-components, tanstack-router-patterns, async-params, nextjs-16-upgrade).

Load full capability details: Read("${CLAUDE_PLUGIN_ROOT}/skills/react-server-components-framework/references/capability-details.md")