I agree with this post. I very rarely consider using a service's API without a client library. Taking the load off authentication and marshaling is incredibly valuable in my development workflow. Granted, sometimes simple REST endpoints are OK if they are public / don't need complicated authentication.<p>I think the major benefits of client libraries is the ability for a developer to stay within their programming language / business domain and not stray into the fun of HTTP and JSON.<p>Curious how much burden this makes for providers though and what people have done to streamline the testing of the various client libraries with different versions of the service.