Next.js App Router Patterns

Quick Guide: Server Components are the default and "use client" is opt-in, so keep client components small and at the leaves of the tree. Reads happen in Server Components; writes happen in Server Actions, which are public HTTP endpoints and revalidate the cache themselves. Two version facts change the answers below: from 15, params, searchParams, cookies() and headers() are Promises; in 16, middleware.ts became proxy.ts, revalidateTag() takes a cacheLife profile, and experimental_ppr became cacheComponents.

Detailed Resources: