Coupa exposes the web service API that the Secure Agent uses to perform integration tasks through the REST protocol.
When you create a mapping, you can associate a Coupa V2 connection and an operation. The Secure Agent connects to the web service to access, transform, or write data. The request and response are REST messages. The REST request and response messages contain hierarchical data, where the data follows a JSON schema. If you want to write data to a relational target, the Secure Agent converts the hierarchical data fetched from Coupa to relational data.