Communicating with Microsoft Dynamics NAV Client

Hello,

My name is Sofiene Zine, I’m an engineering student trying to develop an APS (www.apsstandard.com) for Dynamics NAV 2013 R2 to make it multi-tenant (SAAS). I need to know if there’s documentation or a guide to explain how to communicate with the NAV product, something like an API Restful.

Thank you

Why would you need to “make it multi-tenant”, when it already is?