Verify Amazon Simple Pay w/Python

I've spent two whole days trying to figure out how to verify return signatures using Amazon's simple pay button. It's not feeling so simple anymore. Isn't there just an Amazon URL that I can make a server-si开发者_如何学运维de call to? All I can find are difficult to understand APIs and examples that never show any URLs. Can anyone help me with square one?

• I have my button generated
• I have a python script listening at the return URL. It captures all of the GET data. I just don't know what to do with it.

Thanks everyone,

-s

Sorry to zombie this question but I had this same problem, ended up writing my own solution: https://gist.github.com/1206481