---
description: Next.js 15+/16 App Router rules
globs: ["app/**", "components/**", "lib/**", "*.ts", "*.tsx"]
alwaysApply: true
---

# Next.js rules

- Server Components by default. Use `"use client"` only when truly needed.
- `params`, `searchParams`, `cookies()`, `headers()` are Promises — `await` them.
- Fetch on the server. Keep client components small and stateful only.
- No `any`. Type props explicitly.
- Tailwind only for styling. Use `cn()` for conditional classes.
- No `getServerSideProps` / `getStaticProps`.