SUMMARY When Firefox is run through Flatpak, the Browser Integration extension is unable to communicate with the native host. STEPS TO REPRODUCE 1. Install and run Firefox from Flathub's official Flatpak release 2. Start playing anything Browser Integration supports (YouTube, Nextcloud...) OBSERVED RESULT No MPRIS player shows up. Play/pause controls do not work, and no media playing status is reflected through KDE Connect EXPECTED RESULT A matching MPRIS player for the media currently playing appears, the system's play/pause controls can control it, and KDE Connect shows the media on paired devices. SOFTWARE/OS VERSIONS Linux/KDE Plasma: Arch Linux x86_64, Kernel 5.6.12-AMD (available in About System) KDE Plasma Version: 5.18.5 KDE Frameworks Version: 5.70.0 Qt Version: 5.14.2-2 ADDITIONAL INFORMATION Firefox: Official Flatpak from Flathub (org.mozilla.firefox) 75.0
Sandboxing doesn't permit native messaging at this time.
I managed to make the native connector work, by allowing the Firefox flatpak to access dbus name org.freedesktop.Flatpak and using flatpak-spawn, but I suspect that running the native Plasma connector within the Flatpak sandbox is susceptible to working as well (if it works through D-Bus) My idea is that native connectors for Firefox should be Flatpak extensions (a natively supported paradigm), but that is a problem for the Firefox Flatpak maintainers over at Flathub.
If you could raise that issue there that would be highly appreciated! :)
Is there any news on this issue ? This is still an issue in 2025