I recently took an online exam using a Edge extension called Proctorio.

I was under the impression that browsers did not let sites or extensions view anything on the user's computer outside the browser.

To my surprise however, when starting up the exam, I was allowed to select what to show the proctoring service, and in the browser I was able to select my Spotify window (installed locally on my computer, not the website), my IDE window, etc. So it would seem by enabling this extension for the Edge browser it could indeed view applications running outside of my browser.

Does anyone know how this works?

I've read that Edge extensions can connect to host applications on your computer (if a host application is installed), but shouldn't this be detailed somewhere before the user consents to the installation? I couldn't find any mention of this. I also couldn't find evidence of a host application being installed on my system (although I did not look particularly hard).

Or is what's going on here similar to the user being able to upload a file to a site via the file explorer? I.e. it requires user permission?

The URL for this post is a link to the extension.