Eloqua 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 an Eloqua REST 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 in the JSON format. If you want to write data to a relational target, the Secure Agent converts the hierarchical data fetched from Eloqua to relational data.