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GET https://api.mock.health/fhir/Patient?_count=5 returns a FHIR Bundle of synthetic Patient resources — each one US Core 6.1 profiled, with real-looking names, identifiers, addresses, and birth dates.
GET https://api.mock.health/fhir/Patient/{id}/$everything returns the complete patient compartment in one Bundle: encounters, conditions, medications, observations, diagnostic reports, imaging studies, and clinical notes. This is the call that shows the difference between a fixture and a patient — mock.health charts are generated by a Markov progression module trained on millions of real patient journeys, so conditions correlate, labs trend, and medications follow diagnoses.
Every resource supports standard FHIR R4 search: Observation?patient={id}&category=vital-signs, Condition?clinical-status=active, MedicationRequest?status=active. Add _include and _revinclude to pull referenced resources in the same Bundle.
Browse the API reference for per-resource search parameters, read the SMART on FHIR guide to add OAuth 2.0 app launch, or see the map to make responses come back shaped like Epic, Oracle Health (Cerner), or MEDITECH. Stuck? Troubleshooting covers the common errors.