← ReferenceStandards
What is the FHIR REST API?
The FHIR REST API defines how clients interact with a FHIR server using standard HTTP methods and a predictable URL pattern. Every Resource type has its own endpoint, and operations map directly to HTTP verbs.
| HTTP | URL | FHIR operation |
|---|---|---|
| GET | /Patient/123 | read — fetch a specific resource |
| GET | /Patient?name=Doe | search — returns searchset Bundle |
| GET | /Patient/123/_history | history — all versions of a resource |
| POST | /Patient | create — server assigns the ID |
| POST | / | transaction/batch Bundle |
| PUT | /Patient/123 | update — full replace, client provides ID |
| DELETE | /Patient/123 | delete — soft delete, 410 Gone after |
| GET | /metadata | CapabilityStatement |
HTTP status codes
200 OK— successful read, update, or delete201 Created— resource successfully created (POST)400 Bad Request— malformed resource or request404 Not Found— resource ID never existed410 Gone— resource existed but was deleted422 Unprocessable Entity— resource fails validation
Content type
All FHIR requests and responses use application/fhir+json (or application/fhir+xml). Error responses return an OperationOutcome resource.