In a desire to make our APIs faster, easier to use, and more flexible, we will be adjusting the Invoice and Budget schemas for the WMS Acquisitions API in the upcoming release, currently scheduled for 6 April.
The updated API will reflect a "linked data" approach to data services, allowing the user to navigate back and forth in the Acquisitions data graph. For instance, navigation from the Invoice to its Vendor or from the Invoice to its line-items is now simpler and more transparent. Additionally, pricing data and other fields re-use elements from common web-based schemas like Schema.org and Good Relations.
We're working on providing you with advanced documentation so that you can be prepared for these changes, which are not backward compatible. We will publish detailed release notes here on Developer Network within the next two weeks.
We've had several conversations with current users to get a better understanding of how you're using the API and what you'd like to do in the future. We hope these changes will result in greater efficiencies for libraries and library developers as well as a more optimized epxerience using our services. We look forward to your feedback as you begin working with the updated schemas.
Please drop us a line here at firstname.lastname@example.org to let us know what you think (the good, the bad, and the "ugly") and we will certainly aim to continue to make more improvements for all services as we move forward.