An endpoint directory addresses the problem of finding a FHIR server.
For example, imagine a Medicaid member whom would like to connect to their state medicaid agency's Patient Access API. As a patient, I know the name of my state, but I won't know the url of the server (and all important CapabilityStatement at <url>/metadata). An endpoint directory translates what the patient knows into a url that a a machine can use.
Indeed, technical specification and adoption of endpoint directories is one of the near-term attainable goals of ONC FAST. As such, there are a number of emerging endpoint directory products.
|Focus||Open Source?||Support?||Availability||Implementation Guide|
|CAQH Endpoint Directory||Payer||No||Yes||Preview|
|CARIN FHIR DIrectory||Payer||Yes||No||GA||No. Flat file.|
|ONC/MITRE Lantern||None||Yes||No||GA||VhDir STU2|
|OneRecord Health Plan Directory for Consumer Apps||Payer, Consumer||TBD||Yes||Proposal|
|FHIR Fly Endpoint Directory||None||TBD||Yes||Preview|
Table: Endpoint directory implementations. GA (General Availability).
The CARIN Alliance application community has also put together a list of best practices for any endpoint directory that may get created. We welcome feedback from the HL7 community on this list. Please feel free to contact Ryan Howells or Mark Roberts with your suggested comments.
Validated Healthcare Directory (VhDir) FHIR IG should become the canonical implementation guide for exchanging information about directories. However, VhDir is on an STU2 ballot and has not been officially released.
The promise of VhDir is that it will allow servers to write their endpoint details once, and reuse them on any endpoint directory where they want to be listed.