The device tier could only take a screenshot and read what Go chose to log, and a screenshot cannot tell a dropped CSS declaration from a missing asset. This adds the third thing: the page's own answer, from the engine that is really rendering it. `make android-screenshot` grabs the screen, `make android-inspect` forwards the WebView's devtools socket, and `make android-eval EXPR=...` evaluates in the real page. Four details are load-bearing. Only a `debuggable` build opens that socket, so the debug build type takes `applicationIdSuffix ".dev"` and installs *beside* the release app -- the two carry different signing certificates, and Android's only remedy for a changed certificate is an uninstall, which takes the user's library with it. Playwright cannot drive a WebView (`connectOverCDP` calls `Browser.setDownloadBehavior`, which it answers "Browser context management is not supported"), so the eval is raw CDP over Node's built-in WebSocket. The socket name carries the pid, so it is resolved per launch rather than written down. And `exec-out`, not `shell`, for the screenshot: a pty translates LF and corrupts the PNG. What it immediately established is why it was worth having. The phone renders in Chrome 113 at 424x439 CSS px -- two years behind every browser the other tiers use, with no Popover API and no relaxed CSS nesting -- so a spec passing at that viewport says nothing about the device, and two conclusions drawn from version numbers alone were wrong. Both are corrected in NOTES.md and the plan.
YellowJacket
Music how it was meant to bee.
YellowJacket is a fast, cross-platform desktop music player for your local collection. It plays your files, keeps your library tidy, and helps you discover and organize your music — all in a clean, responsive interface. No accounts, no streaming, no telemetry: just your music on your machine.
Runs on Linux, macOS, and Windows.
Features
Play your music
- Plays MP3, FLAC, OGG Vorbis, and WAV
- Play, pause, seek, and volume control with a mute toggle
- Gapless, glitch-free seeking backed by a read-ahead buffer
- A queue you can add to, reorder, and shuffle, with play-next support
- Shuffle and repeat (off / all / one)
- Picks up right where you left off — remembers your track, position, and volume between sessions
- Media-key and MPRIS support on Linux, so your desktop's playback controls just work
Keep your library organized
- Point it at your music folders and it scans them automatically
- Reads tags and embedded cover art, and de-duplicates artwork so it isn't stored twice
- Incremental sync — only new or changed files get reprocessed, and deleted files are cleaned up
- Browse by album, artist, or genre, or search across everything
- Mark favorites and see what you've been listening to with play history
- Edit track tags directly when something's off
Playlists
- Create playlists, drag tracks in, and reorder them
- Smart playlists that build themselves from rules (by genre, rating, play count, and more)
- Pin a default playlist and spot duplicate tracks at a glance
Discover and clean up (powered by MusicBrainz)
- Explore — browse artists, releases, and genres from the MusicBrainz catalog, not just what's already in your library
- Auto-tag — match your files against MusicBrainz to fill in correct artist, album, and track metadata, with a review step before anything is written
- Lyrics search — find a track by a line you remember
Install
Download the latest build for your platform from the releases page.
| Platform | Download |
|---|---|
| Linux | yellowjacket-linux-amd64 |
| macOS | yellowjacket-darwin-universal.app.zip (Apple Silicon + Intel) |
| Windows | yellowjacket-windows-amd64.exe |
Prefer to build it yourself? See Building from source.
Getting started
- Launch YellowJacket.
- Open Settings and add the folder(s) where your music lives.
- Let the initial scan finish — you'll see progress as it works.
- Browse by album, artist, or genre, queue something up, and press play.
Your library and settings are stored locally:
| Linux / macOS | Windows | |
|---|---|---|
| Config | ~/.config/yellowjacket/ |
%LOCALAPPDATA%\yellowjacket\config |
| Library data | ~/.local/share/yellowjacket/ |
%LOCALAPPDATA%\yellowjacket\data |
Building from source
YellowJacket is built with Go and a Lit/TypeScript frontend, bridged by the Wails framework.
Prerequisites
| Tool | Version |
|---|---|
| Go | 1.25+ |
| Node.js | 22+ |
| pnpm | 10+ |
| Wails CLI | v3 — vendored, no install needed (go tool wails3) |
The Wails v3 CLI resolves from the tool block in go.mod, so there is nothing
to install globally; make setup fetches it with the rest of the tooling.
On Linux, install the system libraries Wails needs. v3 builds against GTK4 + WebKitGTK 6.0 by default:
sudo apt-get install libasound2-dev libgtk-4-dev libwebkitgtk-6.0-dev # Debian/Ubuntu
sudo pacman -S alsa-lib gtk4 webkitgtk-6.0 # Arch
A machine without webkitgtk-6.0 can still build with -tags gtk3 against the
older WebKit2GTK 4.1 stack, but that is an escape hatch, not what CI or a
release builds.
macOS and Windows need no extra system packages. Run go tool wails3 doctor to
check your environment.
Build
make setup # install tooling and git hooks
make dev # run with hot-reload
make build-prod # produce a release binary
More detail for contributors lives in
docs/dev/overview.md and CLAUDE.md.