CI/CD integration

fhir-resource-diff is designed for CI pipelines — exit codes are severity-aware, output is machine-readable, and --quiet mode produces zero stdout.

GitHub Actions examples

Validate a FHIR payload

- name: Validate FHIR resource
  run: fhir-resource-diff validate payload.json --format json --fhir-version R4

Exits 0 on success, 1 if the resource has errors (invalid JSON, missing resourceType).

Diff against an expected baseline

- name: Diff against expected baseline
  run: |
    fhir-resource-diff compare expected.json actual.json \
      --format json --exit-on-diff --preset metadata --quiet

--exit-on-diff fails the step when differences are found. --preset metadata ignores id, meta.lastUpdated, and other fields that are expected to differ between environments. --quiet suppresses stdout.

Full workflow example

name: FHIR validation

on: [push, pull_request]

jobs:
  validate:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - uses: pnpm/action-setup@v4
        with:
          version: ">=9.0.0"

      - uses: actions/setup-node@v4
        with:
          node-version: lts/*
          cache: pnpm

      - run: pnpm install --frozen-lockfile

      - name: Validate FHIR resources
        run: |
          for f in fixtures/fhir/*.json; do
            fhir-resource-diff validate "$f" --fhir-version R4 --quiet
          done

      - name: Check for unexpected diffs
        run: |
          fhir-resource-diff compare \
            fixtures/expected/patient.json \
            fixtures/actual/patient.json \
            --exit-on-diff --preset metadata

Key flags for CI

Flag	Purpose
--exit-on-diff	Exit 1 when differences are found (compare only)
--quiet	Suppress all stdout — exit code only
--format json	Machine-parseable output
--format json --envelope	JSON with tool version, FHIR version, timestamp
--preset metadata	Ignore id, meta.lastUpdated, meta.versionId, text
--fhir-version R4	Explicit version — avoids auto-detection ambiguity

Exit codes

Code	Meaning
0	Success — no errors, no diff (or diff found but --exit-on-diff not set)
1	Errors found (validation) or diff found with --exit-on-diff
2	Input error — file not found, unreadable, or not valid JSON at all

Exit codes are severity-aware: warning and info findings never produce exit 1. Only severity: error findings trigger a non-zero exit.

Capturing JSON output downstream

When you need to process the output of a validation or diff step in a later step:

- name: Validate and capture result
  id: validate
  run: |
    result=$(fhir-resource-diff validate payload.json --format json --fhir-version R4)
    echo "result=$result" >> $GITHUB_OUTPUT

- name: Check result
  run: |
    echo '${{ steps.validate.outputs.result }}' | jq '.valid'

Using –envelope for structured pipeline output

fhir-resource-diff compare a.json b.json --format json --envelope

{
  "tool": "fhir-resource-diff",
  "version": "0.2.0",
  "command": "compare",
  "fhirVersion": "R4",
  "timestamp": "2026-03-14T15:56:25.686Z",
  "result": {
    "resourceType": "Patient",
    "identical": false,
    "summary": { "added": 5, "removed": 0, "changed": 3, "typeChanged": 0, "total": 8 },
    "entries": ["..."],
    "documentation": "https://hl7.org/fhir/R4/patient.html"
  }
}

The summary counts are useful for automated triage: a step that checks result.summary.total > 0 is more precise than checking the exit code alone.

See also

• Exit codes — full severity model
• Output formats — JSON format documentation
• AI agents & automation — stdin, programmatic patterns