The NCCN Chemotherapy Order Template Tool provides simple FHIR REST Server API capabilities for the read, vread, and history (type and instance) interactions defined at http://hl7.org/fhir/stu3/http.html
The capability statement is available from CapabilityStatement-cott.html as well as from the metadata endpoint of the base FHIR API as described at http://hl7.org/fhir/stu3/http.html#capabilities