How to Use Middleware in Go HTTP Servers

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2026-04-17T12:05:42+00:00
Implement Go HTTP middleware by wrapping http.Handler functions to execute logic before or after the main request handler.

Go does not have built-in middleware; you implement it by wrapping http.Handler functions in a chain. Create a function that takes a handler, returns a new handler, and executes logic before or after calling the original handler.

func LoggingMiddleware(next http.Handler) http.Handler {
    return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
        log.Println(r.Method, r.URL.Path)
        next.ServeHTTP(w, r)
    })
}

func main() {
    mux := http.NewServeMux()
    mux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
        w.Write([]byte("Hello"))
    })
    handler := LoggingMiddleware(mux)
    http.ListenAndServe(":8080", handler)
}