Protocol selection for remote browser control.

[Brandon McGinty]

Hello,

I'm in the very early stages of developing an alternate front end for Firefox.
I'd like to know what interface would be recommended for controlling
Firefox 113+ (CDP, BiDi Webdriver, Marionette)?
It's important that the final webpage act as close to a standard
webpage as possible. E.G. Standard sandbox/security features should be
in place so the webpage can't reach up to the controlling framework.

Marionette: looks to allow all requested features, looks like I can
even access Firefox menus
BiDi: current main focus?
CDP: handles most/all features but looks to be de-prioritized by BiDi

Recommendations and thoughts would be appreciated.

The needed capabilities (in descending priority):
- receive DOM and A11Y tree updates to webpages
- receive page load events
- see what event listeners are available for a given element
- send trusted mouse and keyboard inputs
- access to page content for about:config, and similar internal urls
- inject and run scripts on target webpages (and nested iframes)
- access to javascript debugger

Thank you for your time.

Respectfully,
Brandon McGinty