Since Spring 4.1, it is really easy to enable JSONP on an API controller: @RestController @RequestMapping(value = "/") public class MyController { @ControllerAdvice static class JsonpAdvice extends AbstractJsonpResponseBodyAdvice { public JsonpAdvice() { super("callback"); // name of the query parameter to use } } @RequestMapping(value = "/", method = RequestMethod.GET) public MyAPIResult getStuff(...) { ... } } There is no RFC…