30+ Cursor Rules for every stack

---
description: Next.js 15 App Router rules for Cursor
globs: "**/*.{ts,tsx}"
---

# Next.js 15 — Cursor Rules (.mdc)

## Framework Version
- Next.js 15 with App Router ONLY
- React 19 with Server Components by default
- TypeScript 5.x strict mode required

## Architecture
- Server Components by default, "use client" only for interactivity
- Server Actions for all mutations (no API routes for form handling)
- Validate ALL inputs with Zod schemas
- Use `loading.tsx` and `error.tsx` in every route segment

## Routing
- Use route groups: (auth), (dashboard), (marketing)
- Parallel routes for modals and conditional layouts
- Use `generateMetadata()` for dynamic SEO on every page

## Data Fetching
- Fetch data in Server Components, never in client components
- Use `unstable_cache()` for expensive queries
- Revalidate with `revalidatePath()` or `revalidateTag()`

## Rendering
- Prefer streaming with `<Suspense>` boundaries
- Use `next/image` for all images with explicit dimensions
- Use `next/link` for all internal navigation

## Anti-patterns (NEVER do these)
- Never use Pages Router (getServerSideProps, getStaticProps)
- Never use `useEffect` for data fetching
- Never use `any` type
- Never import server-only code in client components
- Never hardcode API keys or secrets
...