Unknown FHIR R4 Resource Type
The resourceType value is not a recognized FHIR R4 resource. The name is either misspelled, miscased, or not part of the R4 specification.
FHIR · Error
The error
Unknown FHIR R4 resource typeWhy it happens
A casing error (patient instead of Patient), a plural (Patients), an R5-only resource sent as R4, or a custom type that does not exist in the standard.
How to fix it
Use the exact, case-sensitive R4 resource name. resourceType is PascalCase and singular: Patient, Observation, MedicationRequest, DiagnosticReport. Confirm the resource exists in FHIR R4.
Example
The snippet below triggers the error:
{
"resourceType": "patient",
"id": "example"
}The corrected version:
{
"resourceType": "Patient",
"id": "example"
}Frequently asked questions
Is resourceType case-sensitive?
Yes. FHIR resource types are PascalCase. "patient", "PATIENT", and "Patients" are all invalid. Only the exact spelling "Patient" is accepted.