You need to give an attribute to the response object by clicking to + sign. The processor must be stopped to add an attribute. Then response is HTTP/1.1 200 OK Date: Tue, 26 Feb 2019 13:27:12 GMT Content-Type: xml Transfer-Encoding: chunked Server: Jetty(9.4.3.v20170317) You may also look at another anwser here https://community.hortonworks.com/questions/86964/setting-custom-http-headers-with-handlehttprespons.html ... View more