Next.js 15 Context Guide for AI Coding (llms.txt + Rules + MCP)

The React framework for the web. Enables full-stack web applications with React Server Components and Turbopack.

1. Next.js 15 Official llms.txt & Clean Markdown Documentation

Official Vercel Registry

Feed this clean, token-efficient Markdown documentation directly to Antigravity, Cursor, or Claude Code to prevent hallucinations and outdated API syntax.

# Standard llms.txt Index Endpoint
https://nextjs.org/docs/llms.txt

# Comprehensive Documentation Bundle
https://nextjs.org/docs/llms-full.txt

Estimated Token Footprint: ~52k tokens (Fits smoothly inside standard 128k/1M context windows)

2. Production-Ready Next.js 15 Cursor Rules (.cursorrules & .mdc)

Next.js 15 App Router, React Server Components (RSC), and server actions guidelines. Save this into .cursor/rules/nextjs.mdc in your project repository.

// Next.js 15 App Router Rules
- Keep components as React Server Components (RSC) by default; mark 'use client' only when hooks/state are needed.
- In Next.js 15, route params and searchParams are asynchronous promises and MUST be awaited.
- Implement data mutations exclusively via async Server Actions with zod validation.
- Use next/font and next/image for Core Web Vitals (LCP/CLS) optimization.

3. Next.js 15 Antigravity & Claude Code System Instructions

Add this concise instruction block to your workspace .gemini/rules or project system prompt.

// Context Anchor for Next.js 15
When writing code for Next.js 15, refer directly to the verified specifications at https://nextjs.org/docs/llms.txt.
Follow strict error-handling and avoid deprecated API calls.

5. Troubleshooting: Common Next.js 15 AI Coding Issues & Fixes

Frequently reported errors when LLMs generate Next.js 15 code without proper context:

⚠️ Proactive Fix: Fix: Next.js 15 sync access to `params` or `headers()` will trigger runtime warnings. Always `await params` in Page props.

6. Best Used With (Next.js 15 Architecture Combos)

Engineers building with Next.js 15 frequently combine these complementary developer frameworks: