Documentation Index
Fetch the complete documentation index at: https://docs.omophub.com/llms.txt
Use this file to discover all available pages before exploring further.
Overview
Search-type query on ValueSet. FHIR clients - notably HAPI FHIR’s RemoteTerminologyServiceValidationSupport and EHRbase’s FhirTerminologyValidation - call this endpoint as a preflight check: “does this server support the ValueSet I’m about to query?”. If the returned searchset Bundle contains a matching entry, the client proceeds to expand](/api−reference/fhir−terminology/expand)or[ValueSet/validate-code. If the Bundle is empty, the client skips OMOPHub entirely for that ValueSet.
OMOPHub recognizes the same implicit ValueSet URL patterns that $expand handles - no stored ValueSet definitions required.
Request
curl "https://fhir.omophub.com/fhir/r4/ValueSet?\
url=http://snomed.info/sct?fhir_vs=isa/73211009" \
-H "Authorization: Bearer YOUR_API_KEY"
Parameters
| Parameter | Type | Required | Description |
|---|
url | uri | No | Implicit ValueSet URL to check support for. Omit to request an empty Bundle (OMOPHub does not enumerate every possible implicit ValueSet). |
Supported URL patterns
| Pattern | Meaning |
|---|
{system}?fhir_vs | All concepts from a code system |
{system}?fhir_vs=isa/{code} | Descendants of a specific concept (is-a filter) |
{system} is any of the supported FHIR system URIs, and {code} is a code within that system.
Response (supported)
{
"resourceType": "Bundle",
"type": "searchset",
"total": 1,
"entry": [
{
"fullUrl": "https://fhir.omophub.com/fhir/r4/ValueSet/http---snomed-info-sct-fhir-vs-isa-73211009",
"resource": {
"resourceType": "ValueSet",
"id": "http---snomed-info-sct-fhir-vs-isa-73211009",
"url": "http://snomed.info/sct?fhir_vs=isa/73211009",
"status": "active",
"experimental": false,
"name": "OMOPHub implicit ValueSet: http://snomed.info/sct?fhir_vs=isa/73211009",
"description": "Implicit ValueSet backed by the OMOPHub FHIR Terminology Service. Call $expand on this ValueSet to enumerate its members."
}
}
]
}
Response (unknown URL)
{
"resourceType": "Bundle",
"type": "searchset",
"total": 0
}
Double percent-encoding tolerance
Spring-based clients (HAPI, EHRbase) sometimes encode the url parameter twice - once for the template or code (terminology://fhir.hl7.org/ValueSet?url=http%3A%2F%2F...) and again when building the outbound HTTP request. OMOPHub detects the second encoding layer automatically and decodes it before parsing the implicit URL. Single-encoded URLs work too.
Errors
Only malformed requests return errors - unknown URLs are handled via the empty-Bundle response.
| HTTP | Issue Code | Cause |
|---|
| 401 | login | Missing or invalid API key |
See Also
