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Custom Operations

Medplum supports custom FHIR operations implemented via Bots. This allows you to define your own operations with custom business logic while following FHIR operation semantics.

Overview​

Custom operations enable you to:

  • Build domain-specific APIs: Create custom endpoints tailored to your organization's specific healthcare workflows
  • Implement business logic: Add complex validation, calculation, or transformation logic as reusable operations
  • Extend FHIR capabilities: Add functionality beyond standard FHIR operations while maintaining API consistency
  • Create integration endpoints: Receive data from external systems in specific formats

Quick Example​

Custom operations are created by:

  1. Creating a Bot resource with your JavaScript implementation
  2. Creating an OperationDefinition resource that defines the operation's interface
  3. Linking them using a Medplum-specific extension

Once configured, operations can be invoked like any standard FHIR operation:

POST [base]/[ResourceType]/$my-operation
GET [base]/[ResourceType]/[id]/$my-operation

Full Documentation​

For complete documentation on creating and using custom FHIR operations, see:

Custom FHIR Operations Guide

The full guide covers:

  • Creating and deploying Bots for custom operations
  • Defining OperationDefinition resources with proper parameters
  • Configuring system, type, and instance-level operations
  • Input and output handling for POST and GET requests
  • Security and permissions model
  • Error handling patterns
  • Complete working examples