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FHIR Implementation Guides

The server can load FHIR packages from your preferred IGs at startup. Loaded packages contribute profiles and search definitions used by validation and the generated CapabilityStatement.

Configure packages​

In config.yaml:

ig:
  packages:
    - hl7.fhir.us.core@6.1.0
    - hl7.fhir.us.carin-bb@2.0.0
  registryUrl: https://packages.fhir.org
  forceReload: false
  cacheDir: .fhir-ig-cache

Or use environment variables:

export IG_PACKAGES="hl7.fhir.us.core@6.1.0,hl7.fhir.us.carin-bb@2.0.0"
export IG_REGISTRY_URL="https://packages.fhir.org"

Package entries may use name@version or a direct .tgz URL.

Startup behavior​

For each configured package, the loader:

  1. Resolves and downloads the package when it is not cached.
  2. Extracts relevant StructureDefinitions and SearchParameters.
  3. Stores package and profile metadata in PostgreSQL.
  4. Updates the in-memory registries used by validation and search.

Previously loaded packages are skipped unless IG_FORCE_RELOAD=true.

Verify loaded profiles​

Read the server CapabilityStatement:

Request
curl -sS http://localhost:9090/fhir/r4/metadata | jq

Loaded packages appear as canonical URLs in CapabilityStatement.implementationGuide; supported profiles and search parameters appear under the per-type entries in rest[0].resource:

Request
curl -sS http://localhost:9090/fhir/r4/metadata | jq '.implementationGuide'
Response
[
  "http://hl7.org/fhir/ig/hl7.fhir.us.core/6.1.0"
]

An empty array means no packages are loaded — check the startup logs for load failures.

tip

Pin package versions. An unpinned package source makes startup behavior and validation rules harder to reproduce across environments.