suitecrm / sugarcrm External API Connector

I am trying to implement a Sage One API (REST) connector in SuiteCRM (SugarCRM 6.5) without success. There is documentation, but it doesn’t say how and where to actually connect to an external API.

At the moment, I’ve resorted to adding a “before_save” module logic hooks and updating, or getting, info manually from the External API from there. But I’m not sure if this is the correct approach or if I’m missing something.

Where and how do I store the user’s Sage One login details? (Right now I’m just hard coding them to get a POC working.)

I can also see there are things like EAPM class, EAPM controller, eapmBean, et cetera, but I’m not sure what they do, or how to implement them. (And I haven’t been able to find documentation regarding these either).

Is there anybody who’ve been able to implement a SuiteCRM or SugarCRM connector successfully that can point me in the right direction?