There was a similar addon many years back called ThirdVoice or something like that with the same idea. A question I had for them and I suppose it applies here is, does your addon only query your site when the person presses a button or does it send browsing data for all sites to you without user interaction? This would come up as a matter of privacy/tracking.

I didn't know about ThirdVoice, thanks for letting me know.

The addon sends a request to the server every time the URL changes, without the user pressing a button (such as: a new tab is opened, the active tab changes)

The only reason for that is to get the comments for the current page. I could make this happen when the user clicks on a button but I thought that would make the experience slower and/or worse.

I do agree with the privacy part and I care a lot about that. There is absolutely zero tracking right now. There is no way to link or match requests to any particular user.

You can also verify that by checking the Network tab. The request will only include the current URL without any additional data.

I wanted to make this open-source to provide visibility but it will make it very easy for anyone to just copy it and submit as a new extension. If you have an idea about how I can make this open-source without people easily copying it, I'd be more than happy to know.

No idea why your comment was flagged. Fixed that for now. I think it's good to let people know if the addon submits URL's without user-interaction. In my opinion it may be good to let people opt-in per site with a button and then have an option to revert to the current behavior if people decide they are fine with submitting this data for every site they visit.

There is no way to link or match requests to any particular user.

I think that people will disagree with this as their IP address would show up on your servers and then further tracking would depend on what other code gets added to the server. This is why some people for example disable the OCSP validators in the browser as it is yet one more place their behavior is tracked.

If you have an idea about how I can make this open-source without people easily copying it, I'd be more than happy to know.

This is called code obfuscation and if Mozilla are reviewing addons they should flag it. I do not believe there is a way to accomplish what you are describing without making the addon and service proprietary and paywalled. I would not expect that to be adopted as there have been other addons in the past that have tried to enable site comments. They usually do not last long as the comment system gets abused by spammers, scammers, grifters, etc... I suspect this system would need a small army of moderators if the goal is to have a per-site-comment-system. There should also be a flagging system in the addon to report the aforementioned items.