OB-004 is the first record to enter the catalogue before its first public release. That is allowed. A record says what a thing is and what state it is in; Beta is a state.
The observation
Jellyfin is a media server with an excellent web interface, and most people watch it in a browser tab. A browser tab is a fine way to browse and a poor way to play: it costs the memory of a browser, it cannot use the desktop's video decoders directly, and anything the browser cannot decode the server has to transcode. Meanwhile every file on the server is already in a format a desktop player handles perfectly.
The decision
Build a native desktop client that plays the file as it is. JellyBridge started on 20 May 2026 as a Kotlin app and was rewritten in Rust with egui. mpv is built into the packages and loaded only when something plays, so the server never transcodes and nothing else needs installing. The interface follows Jellyfin's own web app closely, on purpose: anyone who knows Jellyfin knows where everything is.
The other decision was to measure instead of guess. Every performance change started from a reproducible scenario on one machine. Launch to content went from 302 to 102 milliseconds, browsing memory from about 170 MB to about 118 MB, and an idle window now draws nothing. Several obvious fixes measured as no gain and were dropped. The method is written up in the repository for anyone who wants to check it.
The working result
Version 0.1.0 is packaged for Debian and Ubuntu, Fedora and openSUSE, Arch, any Linux as an AppImage, Windows 10 and 11, and macOS on Apple silicon and Intel. The Linux and Windows packages were installed and tested on eleven systems; the macOS builds are signed and notarized by Apple. The public release is being prepared; until it is on the release page, JellyBridge builds from source, and the record says Beta. It is free software under the GPL, and it lives at jellybridge.oddbench.co.