How to implement a simple Google Checkout callback function with Django?

I have a simple 'Buy Now' Google Checkout button on my Django site (very simple; no basket or anything more fancy). What I want is for Google to send a notification to a URL on my server once a new order has been processed. The notification should tell me the custom开发者_StackOverflower's email address and name (preferably as simple POST params). Then I can take this info and set up a user account, send out a confirmation email, etc.

This sounds simple. However, all I can find by way of documentation on Google's site is a dense and impenetrable thicket of competing versions, protocols, and APIs with no clear tutorials or example code. It is a nightmare.

Furthermore, I can see no obvious way of testing out the functionality. I continually see references to a 'sandbox', but I can find no concrete information on what this is or how to set it up. The URL 'sandbox.google.com' returns a 503 error.

Can anybody give me a pointer?

Thanks in advance.

Tom

Take a look at how Satchmo handles notifications in: payment.modules.google