fhir-developer

Validate only fields with cardinality starting with 1 (e.g., Observation.status and code), returning 422 Unprocessable Entity for missing or invalid values. Wrap all errors in an OperationOutcome resource with severity, code, and diagnostics, using the application/fhir+json content type.

Return 201 with a Location header on create, 204 on delete, 404 for missing resources, 412 for If-Match ETag mismatches, and 422 for validation failures. A common mistake is returning 400 for enum validation errors instead of 422.

SMART v2 scopes follow the pattern context/resource.permissions, such as patient/Observation.rs for read and search. Contexts are patient, user, or system; permissions are c, r, u, d, s. Legacy v1 scopes like patient/Patient.read map to patient/Patient.rs.

Transaction bundles are atomic: all entries succeed or the entire bundle rolls back. Batch bundles process each entry independently, allowing partial success with per-entry status codes in the response.

Only status and class are required on Encounter in FHIR R4. The subject and period fields are 0..1 (optional), and class uses a Coding directly rather than a CodeableConcept.

Yes, run the included scripts/setup_fhir_project.py with a project name to generate a FastAPI project containing Pydantic v2 FHIR models, OperationOutcome helpers, Patient CRUD endpoints, and basic tests.