Path-level diff

Compare two FHIR resources field by field. Every added, removed, and changed value is tracked with dot-notation paths and array index tracking — including nested CodeableConcepts, extensions, and identifiers.

Structured validation

Catch common FHIR mistakes before submission — id format, date patterns, reference string shape, known resource types — with severity levels (error, warning, info) and links to HL7 documentation.

CI/CD native

--exit-on-diff fails a build step when resources diverge. --quiet suppresses stdout for exit-code-only gates. --envelope wraps output in a metadata envelope for automated triage. Exit codes are severity-aware.

AI agent friendly

Every command supports stdin pipes, --format json for structured output, and --envelope for metadata wrapping with tool version, FHIR version, timestamps, and HL7 doc URLs. No temp files, one pass.

# Install npm install -g fhir-resource-diff # Validate a resource fhir-resource-diff validate patient.json --fhir-version R4 # Compare two resources fhir-resource-diff compare expected.json actual.json # Diff with JSON output for automation fhir-resource-diff compare a.json b.json --format json --envelope

Part of the FHIR operations toolkit

Three focused CLI tools built for FHIR development workflows. Each does one job well — compose them in shell pipelines, CI steps, or AI agent chains instead of reaching for a single monolithic toolkit.

Tool

Purpose

fhir-resource-diff (this)

Diff, validate, and inspect FHIR resources

fhir-capability-analyzer

Analyze and compare FHIR server CapabilityStatements

fhir-test-data

Generate valid FHIR test resources across 14 locales

The tools are independent — use one, two, or all three in any combination that fits your pipeline.

fhir-resource-diffDiff. Validate. Inspect.

Path-level diff

Structured validation

CI/CD native

AI agent friendly

Part of the FHIR operations toolkit ​

Part of the FHIR operations toolkit