On your second paragraph... I don't think you can generally state that REST APIs don't need to be developable, supportable, teachable/learnable. Ad hoc requests

On your second paragraph... I don't think you can generally state that REST APIs don't need to be developable, supportable, teachable/learnable. Ad hoc requests support these things in useful ways that scripted requests do not. That makes it a fair goal for REST APIs. On your first paragraph, sorry I don't understand your point. I showed how this can be done in a way that is fully consistent with standard content negotiation, like your example.