Thanks, Jens! Your tip along with using getSerializationPolicyName() from the ServiceDefTarget worked like a charm.
I ended up using this on the client: final ServiceDefTarget serviceTarget = (ServiceDefTarget) storage; serviceTarget. setRpcRequestBuilder(new RpcRequestBuilder() { @Override protected RequestBuilder doCreate(String serviceEntryPoint) { RequestBuilder builder = new RequestBuilder(RequestBuilder.GET, "/my/url/" + key1 + "/" + key2); builder.setHeader(SERIALIZATION_POLICY_HEADER, serviceTarget.getSerializationPolicyName()); return builder; } }); And this on the server in my RemoteServiceServlet: String moduleBaseURL = request.getHeader(RpcRequestBuilder.MODULE_BASE_HEADER); String strongName = request.getHeader(Headers.SERIALIZATION_POLICY_HEADER); SerializationPolicy serializationPolicy = this.getSerializationPolicy(moduleBaseURL, strongName); MyResult result = MyService.getInstance().getResult(id); Method method = MyService.class.getMethod("getResult", new Class[] { Id.class }); return RPC.encodeResponseForSuccess(method, result, serializationPolicy); -- You received this message because you are subscribed to the Google Groups "Google Web Toolkit" group. To view this discussion on the web visit https://groups.google.com/d/msg/google-web-toolkit/-/6WEtN3MYTnUJ. To post to this group, send email to google-web-toolkit@googlegroups.com. To unsubscribe from this group, send email to google-web-toolkit+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-web-toolkit?hl=en.