The Objects API and the Objecttypes API are two components that complement each other. The Objecttypes API holds the object definitions for objects that can be stored in the Objects API. Together they provide a powerful way to create and store any kind of object.
Designed in line with the Common Ground model, they can be used by other APIs that need to store object specific data.
Both the Objects API and the Objecttypes API are and only use Open-source.
To get you started, you might find some of these links relevant:
Standardize various types of objects in an accessible way and without the need to create a whole new API for each (simple) object.
This national level API is required for registering objects in local Objects API. Organizations can also run the API locally, to use both national and local definitions of objects.
Easily store and expose various objects and make them available in a standardized format. It can be used by any organization to manage relevant objects. An organization can also choose to use it to expose objects to the public as Open Data.
To define the format of objects, organizations can use a national and/or local Objecttypes API.