from zope.interface import implements, Interface
from twisted.python import log, components
from twisted.application import internet, service
from twisted.internet.defer import inlineCallbacks, returnValue
from twisted.fats.service import FastAGIFactory, IFastAGIFactory, CallHandler


class HelloCallHandler(CallHandler):
    """My first call handler.
    """
    def startCall(self):
        log.msg('Hello FastAGI logging system.')
        # Answer the call.
        df = self.agi.answer()
        
        # Say number and stop call session
        df.addCalback(lambda _: self.agi.sayNumber(666))
        return df

$ twistd -ny fats-trunk/fats/examples/hello_agi.py

[-] Log opened.
[-] twistd 2.5.0+rUnknown (/usr/bin/python 2.5.1) starting up
[-] reactor class: 
[-] __builtin__.HelloFastAGIFactoryFromService starting on 9000
[-] Starting factory <__builtin__.HelloFastAGIFactoryFromService instance at 0xb780580c>
[FastAGIProtocol,0,127.0.0.1] Hello FastAGI logging system.
[FastAGIProtocol,0,127.0.0.1] Send Command: 'ANSWER'
[FastAGIProtocol,0,127.0.0.1] Send Command: "SAY NUMBER 666 ''"
[FastAGIProtocol,0,127.0.0.1] SAY NUMBER:[0(), None(), None()]
[FastAGIProtocol,0,127.0.0.1] Call handler result: SAY NUMBER:[0(), None(), None()]
[FastAGIProtocol,0,127.0.0.1] Connection terminated to the FastAGI server 3077895596