for delphi platform you can implement custom server that accepts parameters in url (i.e. GET method) via HTTPServer.OnCustomResponseEvent event.
as a result, your server can accept something like (in example is used the post message)
http://localhost:8099/xxxx?__MessageType=Message&__InterfaceName=MegaDemoService&__MessageName=GetServerTime&__ClientId=b51199fe-9e86-4aa1-8cb1-54b4e05ab131
and receive answer like
__MessageType=Message&__InterfaceName=MegaDemoService&__MessageName=GetServerTimeResponse&__ClientID=B51199FE-9E86-4AA1-8CB1-54B4E05AB131&"Result=2015-08-18 19:01:50"
see Using OnCustomResponseEvent in a ROSDK Server code snippet and related topics in that article