Browser MCP uses the Chrome DevTools Protocol (CDP) to automate the browser so it currently only works for Chromium-based browsers.

Unfortunately, Firefox doesn't expose WebDriver BiDi (the standardized version of CDP) to browser extensions AFAIK (someone please correct me if I'm mistaken!), so I don't think I can support it even if I tried.

Just found this[0] implementation roadmap on Mozilla's wiki, recently updated too! At least it's actively being worked on.

Not going to lie, this makes me happy.

[0]: https://wiki.mozilla.org/WebDriver/RemoteProtocol/WebDriver_...