The problem was found by pylint '(used-before-assignment) Using variable "X" before assignment'
These classes are intended for use server-side.e.g. in a django view.py : from pyjs.jsonrpc.django import JSONService, jsonremote jsonservice = JSONRPCService() @jsonremote(jsonservice) def test(request, echo_param): return "echoing the param back: %s" % echo_param