Subscription requirement
The Custom Fields API is only available to customers on the Evolve & Expand or the Lift & Leap subscription packages.
Use the custom field values API to set values on fields defined using the custom fields definitions API.
Before calling this API a custom field should be defined using the definitions API. Once a field is defined you will need to create a value on an entity.
OpenAPI Specification for the Custom Fields API domain
Get the OpenAPI Specification (formerly Swagger), which is a standardized format that describes the functionalities, endpoints, parameters, and data models of this API in a JSON file here.