generated: '2026-08-14'
method: probed
source: https://open.epic.com/Endpoints/R4
docs: https://open.epic.com/MyApps/Endpoints
note: >-
  Epic publishes a live, anonymous, machine-readable directory of every
  production FHIR base URL its customers run - served as HL7 FHIR Endpoint
  Bundles at open.epic.com/Endpoints/<version>. This is the closest thing Epic
  operates to an RFC 9727 /.well-known/api-catalog, and it matters more than the
  well-known probe result: the Epic FHIR API has no single production base URL,
  because each community member hosts its own instance, so this document IS the
  resolution layer between "Epic" and a callable host. Each entry is a FHIR
  Endpoint resource carrying the organization name (as a contained Organization),
  status, connectionType hl7-fhir-rest, payload type/MIME, and the base
  `address`. Both bundles were fetched anonymously with no credentials and saved
  verbatim; the /.well-known/api-catalog path on epic.com and open.epic.com
  returns 404/302 (recorded in well-known/epic-systems-well-known.yml), so this
  catalog is discoverable only from the docs, not from a well-known path.
catalog_format: HL7 FHIR Endpoint Bundle (Bundle.type=collection)
anonymous: true
bundles:
- fhir_version: R4
  url: https://open.epic.com/Endpoints/R4
  http_status: 200
  file: epic-fhir-endpoints-r4.json
  endpoint_count: 479
  bundle_timestamp: '2026-08-14T16:06:52.428652-05:00'
- fhir_version: DSTU2
  url: https://open.epic.com/Endpoints/DSTU2
  http_status: 200
  file: epic-fhir-endpoints-dstu2.json
  endpoint_count: 490
  bundle_timestamp: '2026-08-14T16:06:52.8817942-05:00'
- fhir_version: STU3
  url: https://open.epic.com/Endpoints/STU3
  http_status: 200
  file: null
  endpoint_count: 0
  bundle_timestamp: '2026-08-14T16:06:53.7997977-05:00'
  note: >-
    Served and valid, but EMPTY - zero Endpoint entries. Recorded because it is
    a real finding: STU3 remains a documented Epic FHIR version with a live
    sandbox CapabilityStatement, yet no customer publishes an STU3 production
    endpoint through this directory. Read alongside
    lifecycle/epic-systems-lifecycle.yml, this is the strongest available public
    signal of where STU3 actually stands in Epic's estate.
endpoint_resource_fields:
- resourceType
- id
- contained[] (Organization - the health system name)
- status
- connectionType (http://terminology.hl7.org/CodeSystem/endpoint-connection-type = hl7-fhir-rest)
- name
- managingOrganization
- period
- payloadType
- payloadMimeType
- address (the FHIR base URL)
example_address: https://haiku.wacofhc.org/FHIR/api/FHIR/R4/
interpretation: >-
  DSTU2 (490) still outnumbers R4 (479) in published production endpoints even
  though R4 / US Core is the version Epic directs all new development to. The
  legacy trial-use version is not a rounding error in this estate; it is the
  larger published surface.
related:
  well_known: well-known/epic-systems-well-known.yml
  lifecycle: lifecycle/epic-systems-lifecycle.yml
  capability_statements:
  - fhir/epic-fhir-r4-capabilitystatement.json
  - fhir/epic-fhir-stu3-capabilitystatement.json
  - fhir/epic-fhir-dstu2-conformance.json
x-evidence:
  fetched: '2026-08-14'
  urls:
  - {url: 'https://open.epic.com/Endpoints/R4', http_status: 200, content_type: application/json}
  - {url: 'https://open.epic.com/Endpoints/DSTU2', http_status: 200, content_type: application/json}
  - {url: 'https://open.epic.com/Endpoints/STU3', http_status: 200, content_type: application/json}