Helix AU Core - Local Development build (v0.1.0) built by the FHIR (HL7® FHIR® Standard) Build Tools. See the Directory of published versions

Custom Operations

Custom Operations (July 2025)

Overview

Custom operations in FHIR are extensions to the standard RESTful interactions (such as Create, Read, Update, Delete). They allow to define custom logic that wraps multiple steps or applies business rules that go beyond basic resource manipulation. It is used in appointment booking, submitting structured data, or matching patients.

Usage Context

These operations are invoked using a dollar sign prefix (e.g., $getSlots) and can be used to:

• Perform complex logic on the server
• Operate across multiple resource types
• Trigger side effects (e.g., merging records, generating reports)
• Enforce business rules or workflow-specific behavior

Supported Custom Operations Scope

Custom operations are categorized by the level at which they are invoked:

System-Level Operations

• Scope: Entire FHIR server.

Type-Level Operations

• Scope: All instances of a resource type.

Instance-Level Operations

• Scope: A specific resource instance.

For more details, see the FHIR Operations documentation

---

$getSlots Custom Operation

Operation Name	Type	Documentation Link
$getSlots	Type-level custom operation	getSlots

This operation retrieves available Slot resources for a given practitioner, location, or service within a specified time window.

---