It's tough to tell how RESTful your API is when it's wrapped up in a client-side library. One of the ways I evaluate this is to ask: if I'm using a compiled cli

It's tough to tell how RESTful your API is when it's wrapped up in a client-side library. One of the ways I evaluate this is to ask: if I'm using a compiled client-side language, and the service api is modified in a backward-compatible way, will I need to recompile my client? With SOAP the answer is often yes because the client-side library generates code that is binary-dependent on the datatypes in the wsdl. That's bad, and one of the huge advantages of a RESTful api is that recompiles aren't needed. Your resource representation can change, so long as the informationn that was there before is still there and can be found using the same expression (eg: an id lookup in an xml document, or by a key in json data.)