Go API Design

APIs are contracts. Once published, they're promises. Design them as if you'll maintain them for a decade — because you probably will.

1. HTTP Handler Structure

Use the standard http.Handler interface:

// ✅ Good — method on a struct with dependencies
type UserHandler struct {
    store  UserStore
    logger *slog.Logger
}

func (h *UserHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
    switch r.Method {
    case http.MethodGet: