The eyepin XML- interface gives you the opportunity to handle data in both directions - import and export data records from your CMS/CRM to eyepin and vice versa.
It's reasonable that most customers prefer to use their own CMS/CRM to track their company related content (e.g. addresses, articles).
The data transfer takes place via XML-records (Extended Markup Language). Depending on what you intend to do, there are special commands for altering (edit, remove, add) data records, which get explained in the following documentation http://docs.eyepin.com/api/intro.
The idea is very simple: a URL is called which passes the data/request to eyepin and you get a response back (response XML).
Furthermore there are so called event-handlers that can perform actions (e.g. calling a URL and transferring data) when something happens to the eyepin user database (e.g. someone changing his personal information).
There are two versions of the API, version 2.X (APIv2) and Version 3.X (APIv3). Both versions are not directly compatible with each other.
The attached document is for APIv2 version.
Documentation for APIv3 can also be accessed via the following link http://docs.eyepin.com/api/intro.
For new projects using eyepin API, the use of APIv3 is recommended.