SMART Sandbox FHIR R4 API
Free, fully open FHIR R4 server loaded with synthetic patient records for app development and testing. No registration or authentication is required - read, search, create, update, and delete clinical resources such as Patient, Observation, Condition, MedicationRequest, Encounter, Immunization, and AllergyIntolerance over plain FHIR REST. Companion open endpoints exist for DSTU2 (r2.smarthealthit.org) and STU3 (r3.smarthealthit.org).