When you are using Integration Server as a REST client and want to invoke the REST APIs that are hosted remotely on a REST API server acting as a provider, you can create a consumer REST API Descriptor (RAD) using an OpenAPI document.

When you create a consumer RAD, Integration Server generates various assets, including a consumer RAD, connector services, and document types. Integration Server generates the document types and uses them in the signature of the connector service. These document types define the data exchange format for the REST operations. A connector service corresponding to each REST operation is a flow service that contains a flow implementation and invokes a REST API operation. The input signature defines the parameters, the request body, authentication information, MIME types, and server URL. The output signature contains the response code returned from the REST API along with the response body. The response body is in the document format. You can run the connector service and provide the necessary inputs and receive the response according to the output of the connector service.