Middleware

Summary

Code that runs before a request completes, at the edge — commonly used for auth redirects, A/B testing, or rewriting URLs based on conditions.

• 1Write a middleware that redirects unauthenticated users away from a protected route.
• 2Learn middleware runs on the Edge Runtime, with a more limited API surface than Node.
• 3Use the `matcher` config to scope which routes middleware runs on.