FHIRcast, published by HL7 International / Infrastructure And Messaging. This guide is not an authorized publication; it is the continuous build for version 3.0.0-ballot built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of https://github.com/HL7/fhircast-docs/ and changes regularly. See the Directory of published versions
The FHIRcast specification can be described as a set of capabilities and any specific FHIRcast Hub may implement a subset of these capabilities. A FHIRcast Hub declares support for FHIRcast and specific capabilities by exposing an extension on the FHIR CapabilityStatement resource as described below.
To support various architectures, including multiple decentralized FHIRcast hubs, the Hub exposes a .well-known
endpoint containing additional information about the capabilities of that Hub. A Hub's supported events, version, and other capabilities can be exposed as a Well-Known Uniform Resource Identifiers (URIs) (RFC5785) JSON document.
Hubs SHALL serve a JSON document at the location formed by appending /.well-known/fhircast-configuration
to their hub.url
. Contrary to RFC5785 Appendix B.4, the .well-known
path component may be appended even if the hub.url
endpoint already contains a path component.
A simple JSON document is returned using the application/json
mime type, with the following key/value pairs:
Field | Optionality | Type | Description |
---|---|---|---|
eventsSupported |
Required | array | Array of FHIRcast events supported by the Hub. |
websocketSupport |
Required | boolean | SHALL have the static value: true - indicating support for websockets. FYI to Implementers: Given that websocket support is the only defined communication method in FHIRcast versions STU3 and was required in STU2, it's likely that this element will become Optional and then Deprecated in the future. |
fhircastVersion |
Optional | string | STU1 , STU2 , or STU3 - indicating support for a specific version of FHIRcast. Hubs SHOULD indicate the version of FHIRcast supported. |
getCurrentSupport |
Optional | boolean | true or false - indicating support for the "Get Current Context" API. |
fhirVersion |
Optional | string | DSTU1 , DSTU2 , STU3 , R4 , R4B , or R5 - indicating the specific version of FHIR for this Hub. |
A field of webhookSupport
SHALL be ignored.
In this example the Hub URL is "www.hub.example.com/".
GET /.well-known/fhircast-configuration HTTP/1.1
Host: www.hub.example.com
HTTP/1.1 200 OK
Content-Type: application/json
{
"eventsSupported": ["Patient-open", "Patient-close", "SyncError", "com.example.researchstudy-transmogrify"],
"websocketSupport": true,
"fhircastVersion": "STU3"
}
To supplement or optionally identify the location of a FHIRcast hub, a FHIR server MAY declare support for FHIRcast using the FHIRcast extension on its FHIR CapabilityStatement's rest
element. Note that client-side Hubs without a client-side FHIR server likely will not support communicating the url of a hub in this extension. See the FHIRcast CapabilityStatement profile.
FHIRcast defines profiles for various FHIR resource structures used in the specification, see summary of artifacts
.
In the context of FHIRcast, must support (MS) on any data element SHALL be interpreted to mean FHIR’s MustSupport. Generally, implementations are expected to: