I think that the answer to your question is no.Obviously, you can use an ESRI SDK such as the ArcGIS Runtime SDK for WPF:http://resources.arcgis.com/en/communities/runtime-wpf/For .NET, I do think that you want to have a set of strongly typed classes which expose async methods that check the result and throw exceptions when it is something other than success.Another approach is to dynamically form and issue requests and then parse the returned JSON. I personally don't think much of this approach but believe that is what ESRI does under the covers. When you start mapping the results to strong types, i.e. classes, you will see seams where the implementation of the REST API is not well done. One example, and there are many, is that some APIs do not document the JSON syntax of the response on failure.I have largely written and used my own classes.