Or it is safer/better to do this by passing commands via POST/GET and formatting response as json? At first look jsonrpc looks just like a tool for this job. But it just not sound secure for me - exposing applications methods to internet etc. Is going to be read/write access without authorization - i don't want to force all the app users to register. Planning to implement it in python, tornado or django.
PS It's possible to do jsonrpc via https? (if it is application specific credentials have sense)