That is, does it connect strictly to the HN and only websites explicitly opened by the user? Or does it talk to something else on the Internet behind user's back?
Everything else is either direct to https://news.ycombinator.com or https://hacker-news.firebaseio.com (the official API). And, of course, sites explicitly opened by the user.
Edit: We also use the readability API for reading mode. https://www.readability.com/
That is, does it connect strictly to the HN and only websites explicitly opened by the user? Or does it talk to something else on the Internet behind user's back?