USPS web services and Ruby/Rails

Hello list,

I was wondering who here already had to work with USPS from within a Rails app to implement fullfilment. I was working with Fedex, implementing not only cost calculation but also the shipping request, void, cancel shipping etc. However, I have no experience with USPS and I don’t know how complete their SOA architecture is. If you have worked with it to some level, would you mind sharing your experiences?