Prevent discord invite links to opening discord app
When you click discord invite links like https://discord.com/invite/xxxxxxxxxxxxxxxxx , Firefox automatically opens discord app and opens join server dialog in Discord app. Even when such link is encountered in private browsing. I'm not comfortable with such behavior. It also rises concerns regarding leaking some browsing information to other apps that might be opened by Firefox without my approval.
Is there a way to prevent Firefox from forwarding links/opening external apps? Force Firefox to at least ask first?
Opaite Mbohovái (1)
Hmm, apparently Discord uses the WebSocket (ws:) protocol to connect to the Discord app listening on a particular port your system.
Off the top of my head, I don't know how to selectively disable WebSockets in private windows, or on particular sites.
Perhaps there is an add-on that can do it??
For sites that use a custom protocol (such as zoommtg://) to trigger an external application, Firefox 84 added a new site-specific permission for protocols that launch external applications. There are now two layers of potential approvals:
(A) This site
(B) Whether Firefox launches the app automatically or asks you every time
So I'm pretty sure -- based on your description and some web searching -- that Discord is not using that method and those protections do not apply.