The primary way of interacting with OpO is over HTTP. Some command line options exist for importing and exporting data as well. The two data model employed are Triples and tree (JSON). JSON has more restrictive primitive options than OpO so 'tree' is used to describe the way data is stored since JSON is an encoding only.
Access to data in the database follows a REST model with CRUD APIs. Under each data model Create, Read, Update, and Delete are included. A Search API is also provided in each.