Ah, maybe I misunderstand what you're trying to do. I thought Hal was trying to make it possible to write clients that can buy from Amazon or eBay without knowing anything about the specifics of either. But actually what it's attempting is a sort of machine-assisted documentation system? (Since you still need a human to read the docs to find out how to signup, place orders, and so on.) I can see how that might work, but it doesn't seem like an important problem to solve.