Health Gorilla supports access to clinical data using the HL7® FHIR® (Fast Healthcare Interoperability Resources) standard. Our platform implements both FHIR R4 and FHIR STU3, depending on the product and use case.

FHIR R4 is used for direct access to normalized FHIR resources and most synchronous API interactions
FHIR STU3 is used by certain legacy workflows and operations, including Patient360 record retrieval and document aggregation.

Locate the R4 or STU3 section on the left for more information about individual resources, operations, and authentication requirements.

Not sure which version you're using? Start with your integration method or API base URL. FHIR R4 endpoints begin with /fhir/R4, while STU3 endpoints use /fhir/3.0.

RESTful Architecture

The Health Gorilla API follows standard FHIR REST conventions. Resources are accessed using standard HTTP methods:

Method	Action
`GET`	Read or search
`POST`	Create
`PUT`	Update
`DELETE`	Remove (where supported)

All requests are constructed using predictable RESTful URLs, for example: GET /fhir/R4/Patient/{id}

Resource paths follow the pattern: https://api.healthgorilla.com/fhir/R4/{ResourceType}/{id}

For example, to retrieve a specific patient record: GET https://api.healthgorilla.com/fhir/R4/Patient/123456

CapabilityStatement (`/metadata`)

To discover available resources, search parameters, and operations, query the server’s CapabilityStatement:

GET /fhir/R4/metadata
GET /fhir/3.0/metadata

Example: GET https://api.healthgorilla.com/fhir/R4/metadata

The CapabilityStatement describes supported resource types, profiles, interaction types, and security models.

Transport Security

All API access must use TLS 1.2 or higher. Plain HTTP requests are rejected.

Accepted: https://api.healthgorilla.com/...
Rejected: http://api.healthgorilla.com/...

Versioning

FHIR versioning is expressed directly in the API path:

R4: /fhir/R4/{ResourceType}
STU3: /fhir/3.0/{ResourceType}

FHIR versions are selected through the API path rather than being negotiated during OAuth token issuance.

If your integration requires a different FHIR version or workflow, contact Health Gorilla Support.

For more information, go to: OAuth 2.0 Authentication

Resource References

FHIR resources commonly reference each other using literal or logical identifiers.

Literal Reference

A relative reference using the resource type and internal FHIR ID:

{
  "reference": "Patient/d5da4352b3f978a445475a22",
  "display": "Tom Sower"
}

Logical Reference

Uses external identifiers such as MRNs, payer identifiers, or other system identifiers to locate related resources.

Medical Record Number (MRN)

{
  "identifier": {
    "type": {
      "coding": [
        {
          "system": "http://terminology.hl7.org/CodeSystem/v2-0203",
          "code": "MR"
        }
      ]
    },
    "system": "https://www.healthgorilla.com",
    "value": "d5da4352b3f978a445475a22"
  }
}

Social Security Number (SSN)

{
  "identifier": {
    "type": {
      "coding": [
        {
          "system": "http://terminology.hl7.org/CodeSystem/v2-0203",
          "code": "SB"
        }
      ]
    },
    "system": "http://hl7.org/fhir/sid/us-ssn",
    "value": "001-01-0001"
  }
}

National Provider Identifier (NPI)

{
  "identifier": {
    "system": "http://hl7.org/fhir/sid/us-npi",
    "value": "1234567893"
  }
}