baz

A music player for the music you already own.
Point it at a folder — a drive, a NAS — and your records are the home screen. Double-click one and it plays front to back, gapless. No account, no subscription, nothing between you and your files.

Public beta. You can find your music, play it, make lists of it, and nothing baz does loses or corrupts anything. It is also pre-1.0 and has rough edges — the ones we know about are listed below rather than left to be discovered. Reports are the point of a beta: open an issue.

What you get

• Your records on a wall. Every album you own, with its cover, arranged by A–Z, artist, year, genre, when you added it or when you last played it. Four densities. baz remembers where you left it.
• It just plays. Gapless between tracks — a live album or a mixed record runs as one piece, with no click and no pause. FLAC, MP3, WAV, ALAC, AAC, AIFF and Ogg Vorbis.
• Nothing touches your files. baz reads your folders and never writes to them: no tags rewritten, no files moved, nothing left behind. Move your music and baz finds it again.
• Start typing to find anything. Any letter, anywhere, searches tracks and albums at once. Enter plays it; one key away is add to the queue instead.
• Playlists you own. Ordinary .m3u8 text files any other player can read, in a folder you can copy. Undo goes eight deep, and deleting a list sends the file to your desktop's trash — never straight to nowhere.
• Playlists by feel. Draw a shape — start quiet, climb, hold, come down — and baz builds a list that follows it by listening to your own library, on your own machine. Six ready-made moods if you would rather just pick one.
• A queue, favourites, shuffle, repeat and a sleep timer. The ordinary things, where you expect them.
• It sounds right. baz plays your files at their own sample rate and changes nothing on the way out; when it has to change something it says so on screen. If your files carry ReplayGain tags it will use them, and it can measure your library itself.
• Shape the sound when you want to. A ten-band equalizer is one click away from every room, with named curves, your own saved presets and automatic headroom protection. Leave it off and the direct, bit-perfect path remains.
• It belongs to your desktop. Media keys, the lock screen and GNOME's and KDE's own controls all drive baz and show the cover.
• Sixteen themes, plus a plain file format for writing your own.

Now playing — cover, rotating jewel case, or a spectrum-led room with no album object.	Playlists — the ones you have made, beside Favourites and the way to a new one. Each is an ordinary .m3u8 on disk.
Immersive Now Playing — live spectrum and chromeless presentation, with every control one gesture away. F11 can take the window full screen.	A record — the sleeve at size, the run in play order, and both editions the library merged.
Search — app-wide, from any place, reaching tracks as well as records.	Equalizer — ten bands, a live response curve, safe auto gain, built-in situations and curves you can save.
Home — the collection at a glance: all songs, recent additions and the way back to the music.	Themes — sixteen built-in rooms, live palette previews, and a local data-only format for your own.

A smart playlist. Draw how the music should move from the first song to the last and baz fills it from your own collection, using what the songs actually sound like rather than what their tags say. Read the words beside the rows down the list: quiet · slow · dark at the top, loud · fast · noisy at the bottom. Every track is analysed on your own machine, and none of your audio leaves it.

These are real screenshots from the shipping binary, captured against the maintainer's real music library — not mock-ups. docs/screenshots/capture.sh refreshes them reproducibly.

The long version of all of this — every audio claim and how it is checked — is in docs/FEATURES.md.

Installing

Downloads for Linux, Windows and macOS are on the releases page. They are unsigned: macOS will refuse the download until you clear the quarantine attribute, and Windows SmartScreen will warn.

Or build it — one command, plus one system package on Linux:

git clone https://github.com/mattcree/baz
cd baz
cargo build --release --locked -p baz
./target/release/baz [MUSIC_DIR]

Linux needs the platform's audio headers to build: libasound2-dev on Debian/Ubuntu, alsa-lib-devel on Fedora, alsa-lib on Arch. macOS and Windows need nothing extra.

baz keeps its index, its playlists and its play history under ~/.local/share/baz/ (and the platform equivalents), and its settings under ~/.config/baz/. Nothing is written next to your music. docs/INSTALL.md has the rest: the Flatpak, the checksum step, and the exact paths on all three platforms.

Linux is the platform baz is developed and used on. The Windows and macOS builds are tested by CI on every change — the same suite, on all three systems — but nobody has sat in front of baz on either.

What baz will not do

This list is a feature, and it is not going to get shorter.

• No account. There is nothing to sign in to and no identity to have.
• No telemetry. baz reports nothing about you, to anyone, ever.
• No cloud or online music service. Your library, analysis and playlists stay on your machine. The optional update check is the sole exception to baz's offline-first default; turn it off in Settings and baz makes no network request. The Flatpak continues to ship without network permission.
• No library anywhere but your disk. The index is a cache of what is in your folders — throw it away and a rescan rebuilds it.
• No writing to your music. Not tags, not filenames, not folder layout.

Keyboard

Start typing to search — that is why every letter shortcut wears a modifier. Nothing has focus when baz starts, so Space plays on the very first frame.

Key	Does
any letter	search tracks and albums
Space	play / pause
← →	seek 5 s (hold Shift for 30 s)
Ctrl+← →	previous / next track
↑ ↓	volume
Ctrl+U	now playing, and what is up next
Ctrl+P	playlists
Ctrl+,	settings
Ctrl+Z	undo the last edit to this list
1 … 6	arrange the wall
Ctrl+scroll	closer or wider
Esc	back out of whatever is open
?	this table, on screen

Media keys work too. The volume media keys are deliberately left alone: they mean your system's volume, and baz's fader is baz's own. The full table, including why shuffle has no key, is in docs/FEATURES.md.

Known limitations

The list that makes the rest of this page worth believing — the ones you can actually hit. The complete set, with the reasoning, is in docs/FEATURES.md and docs/BACKLOG.md.

• Opus files are not played, and they are not listed either. There is no Opus decoder available to baz that does not pull in a C dependency this project has refused elsewhere, so those files are absent rather than shown-and-broken. It reopens the day a beta tester says they have Opus files, so say so.
• AAC albums are not gapless. About 23 ms of silence at each track boundary, because the format's own trim data is not readable here. Every other format baz plays is trimmed.
• A folder you delete leaves its records on the wall. Deliberate: an unmounted NAS and a deleted folder look identical from the filesystem, and wiping a present listener's library to tidy a stale row is the worse failure. A control to forget a record on your say-so is coming.
• Selection is one track at a time. No shift-click run of twelve songs yet — it is the next thing being built.
• A corrupt or hostile file can make the decoder reserve a lot of memory before it reads a byte. On 64-bit Linux this costs nothing measurable; under a container limit it could be an abort. The reasoning for leaving it unguarded — guarding it would mean refusing files that play — is in ADR-0040.

Accessibility — read this before you install

baz has no screen-reader support. Not partial, not planned-for-soon: none. The toolkit it is built on publishes no accessibility tree, and its buttons take no keyboard focus. If you use a screen reader, baz will not work for you today, and we would rather you learn that here than after installing it. That choice was made openly and is published in ADR-0017 §4 rather than inherited quietly.

What baz does guarantee, because being unable to make the big promise is a reason to be strict about the rest:

• Every action has a visible, pointer-reachable control. No action is keyboard-only, and no control's only affordance is hover.
• Contrast floors are tested, every ink against every surface.
• Hit targets have a floor, asserted in the test suite.
• No state is signalled by colour alone.

Under the hood

A Rust workspace: a headless engine does playback and the library, and the interface is a thin client over it, so nothing on screen can make a sample late. baz is developed with substantial AI assistance, openly — and trust is placed in gates anyone can inspect rather than in provenance: rustfmt, clippy with warnings denied, the whole test suite on three operating systems, licence and advisory checks, and scheduled fuzzing of every byte-facing parser in the engine. Audio correctness is asserted against external references — the reference encoders, installed on every test runner — never against baz's own output. A human owns every merge.

docs/FEATURES.md has the detail, docs/ENGINEERING.md is the charter, and docs/adr/ holds every decision of consequence including the ones that went the other way. What has shipped is in CHANGELOG.md; what is next is in docs/WORK.md.

Licence

GPL-3.0-or-later (ADR-0001).