Understand the limited FHIR R4 checks

Use a small, explicit set of checks

The FHIR Resource Checker runs selected checks for R4 4.0.1. It accepts one JSON resource or a Bundle, not a top-level array. supported: true describes supported check scope; it can coexist with error findings.

• Patient: optional name array of nonempty objects, active boolean and gender code. Missing name or id is not an error; individual HumanName elements are not checked.
• Observation: required status and code; the eight R4 status codes, including corrected; selected code/category CodeableConcept and Coding shapes; numeric valueQuantity.value and selected quantity strings.
• Bundle: required type from the nine R4 codes; present entry array, entry objects and fullUrl strings; recursive checks of present entry.resource values.
• OperationOutcome: nonempty issue array, required severity and issue codes, diagnostics strings and details CodeableConcept shapes.

Common checks cover JSON syntax, unique keys, a resource object and resourceType, plus selected id and meta.profile shapes. Listing a profile does not load it or bypass baseline checks.

Locate two concrete issues

{
  "resourceType": "Observation",
  "status": "final",
  "valueQuantity": {"value": "2.00"}
}

Expected error count and JSON Pointer paths:

Errors: 2
/code
/valueQuantity/value

The code element is missing, and the quantity value is a quoted string. The error path identifies the selected field that failed a check.

Correct those issues without overreading the result

{
  "resourceType": "Observation",
  "status": "corrected",
  "code": {"text": "Synthetic measurement"},
  "valueQuantity": {"value": 2.00, "unit": "example units"}
}

Errors: 0
Supported scope: yes
FHIR conformance: not established

The checker accepts the numeric token 2.00 without changing its spelling. This example has no detected errors within the supported rules; the result does not certify the code, units or clinical meaning.

Recognize unsupported input

{"resourceType":"Encounter"}

Supported scope: no
/resourceType: unsupported resource type

Only the four listed resource types have checks. Extension-only enumerated primitives receive an unsupported warning rather than a false missing-code assertion. Contained resources are not checked. Findings stop at a cap with an explicit incomplete-result warning.

Use fuller validation where it is needed

Unlisted fields, profiles, terminology bindings, reference resolution, invariants, slicing, extensions, narratives and Bundle request/response rules are outside this checker. No external profiles or terminology services are contacted. The formatter input and complexity limits also apply.

The official FHIR validation guidance describes checks beyond this tool. Use the relevant base specification and implementation guide when assessing conformance; no detected issues here is only a limited result.