How to create a Firefox extension (add-on) available only for a specific site?

Question

I want to develop an extension that is activated only for a specific domain.
I do not want it to appear in the browser menu without looking at this specific domain.

Can this be done?

Answer 1

Perhaps: for the menu, you can add a popupshowing listener that checks the loaded URL ( docs for the context menu where this will make the most sense ).

(, ) , URL. gBrowser.addEventListener.