Do you mean a Rest Web Service? With Rest, there is no service definition page, like with WCF or ASMX. Usually people want to use a Rest API with JSON.. however.. if you are just looking for a JSON output, and you want your clients to quickly be able to connect to your service, you should consider OData. It’s really easy to create and it makes your data layer accessible for a large number of client languages. They have the OData client library ported for a ton of languages. Submitted as an answer, as requested. : )