With ZnClient you can also dynamically extend paths (#addPath:), specify parameters (#formAt:put:, #queryAt:put:), provide raw #contents:, etc.
But what would be nice is to convert the responses to some domain objects. So e.g. when I query trello for all lists, I would like to get as a result not json, but List instances, where if I asked for cards, it would query the cards from the server.
I recommend also looking at this project by Richard Prinz��
https://www.min.at/prinz/?x=entry:entry150318-104537 which basically discovers the API and generates a nice implementation for it. Then you use the generated API instead of worrying about constructing HTTP requests.
Peter