The Problem

Your Next.js app serves HTML. LLMs, crawlers, and AI agents want Markdown. Today you're stuck choosing between separate endpoints that duplicate your routing and go stale, or Markdown-only pages that break the browser experience for human visitors. The HTTP Accept header already solves this. A browser sends Accept: text/html. An LLM client sends Accept: text/markdown. Your server should respond accordingly - but Next.js has no built-in way to do this.

The Solution

next-md-negotiate intercepts requests that ask for Markdown, rewrites them to an internal API route, and returns the Markdown version you define - all transparently, from the same URL.

• Browser sends GET /products/42 with Accept: text/html - gets your normal Next.js page
• LLM agent sends GET /products/42 with Accept: text/markdown - gets your Markdown version

No new URLs. No duplicate routing. The client just sets an Accept header.

Key Features

• Zero-config content negotiation via standard HTTP Accept headers
• Works with both App Router and Pages Router
• Type-safe parameters inferred from route patterns
• CLI scaffolding with npx next-md-negotiate init
• Published as an npm package for easy integration

Technologies Used

• Next.js - App Router and Pages Router support
• TypeScript - Fully typed API with route parameter inference
• HTTP Content Negotiation - Standards-based approach using Accept headers