Add to your gem file
gem 'active_fulfillment', :git => 'git://github.com/Shopify/active_fulfillment.git'
Contributions are encouraged of course! The basic Fulfillment Service API can be seen in active_fulfillment/fulfillment/service.rb.
New features and patches will have a better chance of getting merged if you include a strong set of tests for your patch or feature. It is also encouraged to try to keep your functions as concise as possible to make review easier as well as to make testing more straightforward.
Copyright (c) 2008 Shopify. Released under the MIT-LICENSE.