Communication between WebGL and .jslib

As mentioned in the doc here

Is there any way to communicate between the .jslib script and the .html of the WebGL build?
How do i reference from the script to the .html file?

I don’t really see the problem you are facing. The jslib file behaves like a normal Javascript file included in your HTML page. You can call any function a normal Javascript could call: document.getElementByID, window.setTimeout, alert, and so on…