OIC integration to retrieve data from R12 EBS

Summary:

What is the recommended approach to retrieve data from EBS into OIC?

Content (please ensure you mask any confidential information):

I'm writing an integration in OIC to retrieve user information along with assigned responsibilities from EBS for a given user. Once retrieved, the data will be then returned as a response in a REST API. A second integration will then update the end date of the assigned responsibilities and/or user.

In reviewing the Integration Repository (EBS ISG), there are many interfaces that create, update or delete but few that fetch data. What is the recommended approach to retrieve data from EBS to OIC. Would this be to use the DB adaptor?