# CQL Namespace URI - Using CQL With FHIR v3.0.0-ballot

## Extension: CQL Namespace URI 

The CQL namespace URI of the CQL library. For Library resources packaged in FHIR NPM Packages, this SHALL be the base canonical of the package.

**Context of Use**

**Usage info**

**Usages:**

* Use this Extension: [CQL Library](StructureDefinition-cql-library.md)
* Examples for this Extension: [FHIRCommon](Library-FHIRCommon.md)

You can also check for [usages in the FHIR IG Statistics](https://packages2.fhir.org/xig/resource/hl7.fhir.uv.cql|current/StructureDefinition/StructureDefinition-cql-namespaceUri.json)

### Formal Views of Extension Content

 [Description Differentials, Snapshots, and other representations](http://build.fhir.org/ig/FHIR/ig-guidance/readingIgs.html#structure-definitions). 

 

Other representations of profile: [CSV](../StructureDefinition-cql-namespaceUri.csv), [Excel](../StructureDefinition-cql-namespaceUri.xlsx), [Schematron](../StructureDefinition-cql-namespaceUri.sch) 



## Resource Content

```json
{
  "resourceType" : "StructureDefinition",
  "id" : "cql-namespaceUri",
  "extension" : [{
    "url" : "http://hl7.org/fhir/StructureDefinition/structuredefinition-wg",
    "valueCode" : "cds"
  },
  {
    "url" : "http://hl7.org/fhir/StructureDefinition/structuredefinition-fmm",
    "valueInteger" : 1
  },
  {
    "url" : "http://hl7.org/fhir/StructureDefinition/structuredefinition-standards-status",
    "valueCode" : "trial-use"
  }],
  "url" : "http://hl7.org/fhir/uv/cql/StructureDefinition/cql-namespaceUri",
  "identifier" : [{
    "system" : "urn:ietf:rfc:3986",
    "value" : "urn:oid:2.16.840.1.113883.4.642.40.37.42.20"
  }],
  "version" : "3.0.0-ballot",
  "name" : "CQLNamespaceURI",
  "title" : "CQL Namespace URI",
  "status" : "active",
  "experimental" : false,
  "date" : "2026-08-14T03:31:27+10:00",
  "publisher" : "HL7 International / Clinical Decision Support",
  "contact" : [{
    "telecom" : [{
      "system" : "url",
      "value" : "http://www.hl7.org/Special/committees/dss"
    }]
  }],
  "description" : "The CQL namespace URI of the CQL library. For Library resources packaged in FHIR NPM Packages, this SHALL be the base canonical of the package.",
  "jurisdiction" : [{
    "coding" : [{
      "system" : "http://unstats.un.org/unsd/methods/m49/m49.htm",
      "code" : "001",
      "display" : "World"
    }]
  }],
  "fhirVersion" : "4.0.1",
  "mapping" : [{
    "identity" : "rim",
    "uri" : "http://hl7.org/v3",
    "name" : "RIM Mapping"
  }],
  "kind" : "complex-type",
  "abstract" : false,
  "context" : [{
    "type" : "element",
    "expression" : "Library"
  }],
  "type" : "Extension",
  "baseDefinition" : "http://hl7.org/fhir/StructureDefinition/Extension",
  "derivation" : "constraint",
  "differential" : {
    "element" : [{
      "id" : "Extension",
      "path" : "Extension",
      "short" : "Namespace name",
      "definition" : "The CQL namespace of the CQL library. For Library resources packaged in FHIR NPM Packages, this SHALL be the packageId of the package.",
      "min" : 0,
      "max" : "1"
    },
    {
      "id" : "Extension.url",
      "path" : "Extension.url",
      "fixedUri" : "http://hl7.org/fhir/uv/cql/StructureDefinition/cql-namespaceUri"
    },
    {
      "id" : "Extension.value[x]",
      "path" : "Extension.value[x]",
      "min" : 1,
      "max" : "1",
      "type" : [{
        "code" : "uri"
      }]
    }]
  }
}

```
