VSAC has two API resources - the VSAC SVS API is based on the IHE SVS Technical Framework, section 2.2.21 Sharing Value Set Integration Profile (SVS), and the IHE SVS XML Schema, and the Fast Healthcare Interoperability Resources® (FHIR®) terminology service for VSAC resources. The FHIR Terminology Service for VSAC Resources is a representational state transfer (REST) API service for accessing the VSAC value sets and supported code systems. Use of VSAC API Resources assumes working knowledge of FHIR resources. Both require a free UMLS license.