Data, relationships, and interactions each come from one or more sources.

For the entity object and the relationship object, multiple source systems can contribute to the attributes of the object. At the time a request for the object is made, survivorship rules at the attribute level within the object will produce an Operational Value (OV) for each attribute of the object, and deliver that OV in the payload of the response.

Each source system is represented in the object by a crosswalk which contains the name of the source and a unique key from that source.