I've built a FastAGI protocol for Twisted, just writing code now to test the various methods. Have already discovered that "HANGUP" doesn't seem to work from a FastAGI application (the MTA just stays on the line even after a hangup).

I've got the whole FastAGI API wrapped as a first-crack hack (at least, as much as is documented in the wiki). There's a lot of messiness in there, some methods return -1 for errors, others -2, others 0, some return extra data values, some return extra key=value pairs. Oh well.

For the curious, here's the "timestamp" sample applications from starpy for FastAGI. It's a (very crude) time service, that is, a service that reads the time to you when you dial in: