The EPP API documentation contains all the information needed to connect to the system and use the EPP API. 

API Guides

The guides serve as a "best practice" foundation for procedures within the system.  

We highly recommend starting with the article Activating, updating or revoking access to the EPP API. In addition, we advise you to read the EPP API basics article for information about connecting to the system.

API reference

The API Reference articles contain information about the object structure of the API. The syntax of different EPP commands are shown using XML examples.