nextjs

name	nextjs
description	Next.js App Router expert guidance. Use when building, debugging, or architecting Next.js applications — routing, Server Components, Server Actions, Cache Components, layouts, middleware/proxy, data fetching, rendering strategies, and deployment on Vercel.
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retrieval	[Truncated]

Next.js Best Practices

Apply these rules when writing or reviewing Next.js code.

File Conventions

See file-conventions.md for:

• Project structure and special files
• Route segments (dynamic, catch-all, groups)
• Parallel and intercepting routes
• Middleware rename in v16 (middleware → proxy)

RSC Boundaries

Detect invalid React Server Component patterns.

See rsc-boundaries.md for:

• Async client component detection (invalid)
• Non-serializable props detection
• Server Action exceptions

Async Patterns

Next.js 15+ async API changes.

See async-patterns.md for:

• Async params and searchParams
• Async cookies() and headers()
• Migration codemod

Runtime Selection

See runtime-selection.md for:

• Default to Node.js runtime
• When Edge runtime is appropriate

Directives

See directives.md for:

• 'use client', 'use server' (React)
• 'use cache' (Next.js)

Functions

See functions.md for:

• Navigation hooks: useRouter, usePathname, useSearchParams, useParams
• Server functions: cookies, headers, draftMode, after
• Generate functions: generateStaticParams, generateMetadata

Error Handling