Currently, Vendor Central does not have an API. Vendors can access Vendor Central via the website, which offers manual data input and basic bulk data import/export using CSV files.
Vendor Central does allow access by EDI (electronic data interchange). EDI is an old technology for sending data between businesses, dating back to the 1970s, but still persists in some industries.
EDI integration is a difficult, highly specialized area, but third-party components such as Logicbroker and Synesty can provide a modern API wrapper for Vendor Central to make custom development easier.