HTTP API

Hades speaks FHIR R4. Operations dispatch to the right terminology provider by canonical URL, so a single endpoint serves SNOMED CT, LOINC, and any loaded FHIR packages.

Operation	Resource	Purpose
$lookup	CodeSystem	Display, designations and properties for a code
$validate-code	CodeSystem / ValueSet	Confirm a code exists / is in a value set
$subsumes	CodeSystem	Relationship between two codes
$expand	ValueSet	Materialise a value set (with optional filter, paging, ECL)
$translate	ConceptMap	Map a code via a ConceptMap or SNOMED map reference set

GET and POST forms are both supported. Operation parameters can be passed as query parameters (GET) or as a Parameters resource in the request body (POST).

tx-resource parameters — temporary CodeSystem, ValueSet, or ConceptMap resources — are honoured per-request and overlay the base catalogue for the lifetime of that request only.

Examples

Lookup a SNOMED concept

curl -H "Accept: application/json" \
  'http://localhost:8080/fhir/CodeSystem/$lookup?system=http://snomed.info/sct&code=209629006'

How do two codes relate?

Test how 107963000|Liver excision relates to 63816008|Hepatectomy, total left lobectomy.

curl -H "Accept: application/json" \
  'http://localhost:8080/fhir/CodeSystem/$subsumes?system=http://snomed.info/sct&codeA=107963000&codeB=63816008' | jq

{
  "resourceType": "Parameters",
  "parameter": [
    { "name": "outcome", "valueString": "subsumes" }
  ]
}

Expand a value set

Ask for every concept that is a Disorder of the respiratory system (<<50043002) with a clinical course (<<263502005) of subacute (<<19939008). Add &filter=sili to drive autocomplete.

curl -H "Accept: application/json" \
  'http://localhost:8080/fhir/ValueSet/$expand?url=http://snomed.info/sct?fhir_vs=ecl/<<50043002:<<263502005=<<19939008' | jq

{
  "resourceType": "ValueSet",
  "expansion": {
    "total": 6,
    "contains": [
      { "system": "http://snomed.info/sct", "code": "22482002",  "display": "Subacute obliterative bronchiolitis" },
      { "system": "http://snomed.info/sct", "code": "233761006", "display": "Subacute silicosis" },
      { "system": "http://snomed.info/sct", "code": "233753001", "display": "Subacute berylliosis" }
    ]
  }
}

Validate a code in a value set

curl -sG 'http://localhost:8080/fhir/ValueSet/$validate-code' \
  --data-urlencode 'url=http://snomed.info/sct?fhir_vs=isa/64572001' \
  --data-urlencode 'system=http://snomed.info/sct' \
  --data-urlencode 'code=73211009' | jq

Translate via a SNOMED map reference set

curl -sG 'http://localhost:8080/fhir/ConceptMap/$translate' \
  --data-urlencode 'system=http://snomed.info/sct' \
  --data-urlencode 'code=73211009' \
  --data-urlencode 'targetsystem=http://hl7.org/fhir/sid/icd-10' | jq

Implicit SNOMED ValueSets and ConceptMaps

Hades supports the SNOMED CT FHIR module's implicit URI patterns:

• http://snomed.info/sct?fhir_vs — every concept in SNOMED CT
• http://snomed.info/sct?fhir_vs=isa/<sctid> — <sctid> and all its descendants
• http://snomed.info/sct?fhir_vs=refset — every installed reference set
• http://snomed.info/sct?fhir_vs=refset/<sctid> — members of the named reference set
• http://snomed.info/sct?fhir_vs=ecl/<expression> — concepts matching an ECL expression
• http://snomed.info/sct?fhir_cm=<sctid> — ConceptMap defined by a SNOMED map reference set

Implicit value sets pinned to a SNOMED edition or version (e.g. http://snomed.info/sct/900000000000207008?fhir_vs=…) are not yet supported — the bare http://snomed.info/sct form resolves against the loaded SNOMED database.