WCF Web API doesn't provide any metadata information you would use to generate a service proxy and thus, be able to add a service reference. It is intended for easy making of REST services under WCF umbrella, just as you do with ASP.NET MVC 4 Web API framework.

Therefore no support for WP7 or Silverlight, but almost perfect for the rest of the web.

However, WCF Data Services looks like a right candidate, it allows you to create RESTful services and easily consume 'em with Silverlight.

The WCF Web API doesn't provide any metadata information you would use to generate a service proxy and thus, be able to add a service reference. It is intended for the easy production of REST services under the WCF umbrella, just as you do with the ASP.NET MVC 4 Web API framework.

Therefore there is no support for WP7 or Silverlight, but it is almost perfect for the rest of the web.

However, WCF Data Services looks like a right candidate, it allows you to create RESTful services and easily consume them with Silverlight.