Routing Middleware

Intercepts requests at the platform level before they hit your cache or framework, so you can rewrite paths, inject headers, do geo-routing, or run A/B tests. Works with any framework Vercel deploys, not just Next.js. Runs on Edge, Node.js, or Bun runtimes. One gotcha: Next.js 16 renames middleware.ts to proxy.ts and forces Node.js runtime, which trips people up if they're importing from next/server. The skill catches that and chains to Next.js guidance. Use this when you need request-level control that sits above your application code, like redirecting by country or adding security headers before anything else runs.