Most Go HTTP servers accumulate authentication logic and rate limiting code directly in handler functions, and it becomes messy fast. When you need to enforce JWT validation and per-IP rate limiting consistently across dozens of endpoints, inline checks don't scale — you end up copy-pasting guard code or missing it entirely on new routes.

Middleware chains solve this cleanly. Here's how to build one properly in Go.

How Go Middleware Works

In Go's net/http , middleware is a function that wraps an http.Handler and returns a new http.Handler :

type Middleware func ( http . Handler ) http . Handler

func Chain ( h http . Handler , middlewares ... Middleware ) http . Handler { for i := len ( middlewares ) - 1 ; i >= 0 ; i -- { h = middlewares [ i ]( h ) } return h }

Enter fullscreen mode

Exit fullscreen mode

Applying in reverse order ensures the first middleware you list runs first.…