Kase

AirPods for Linux. Best on KDE Plasma.
Accurate battery for each pod and the case, a Dynamic Island over your games,
and AirPods that switch between your iPhone and your PC the way they do with a Mac.

Install · Tour · Features · Compatibility · How it works · FAQ · Development

Note

Kase was called BazzitePods until version 0.5.0. Same app, same developer. Running the install command moves your settings across by itself; see Coming from BazzitePods.

Why Kase

Linux can play music through AirPods, but that is where it stops. There is no battery reading for each pod, no case level, no noise control, and when the AirPods wander off and come back they often connect without sound. Kase fills that gap with a companion app that feels like part of the desktop:

• It just works. Install once and forget it. Kase starts with your session, finds your AirPods by itself and has nothing to set up.
• It shows the truth. Left, right and case levels come straight from the AirPods over Apple's own control channel, the same way an iPhone reads them.
• It's made for gaming. The island floats over fullscreen games, never touches them, and draws nothing at all while it rests.
• It's private. No account and no telemetry. Kase never connects to the internet.

Install

Open a terminal and run:

curl -fsSL https://raw.githubusercontent.com/DaBarkle/kase/main/linux-rust/packaging/install.sh | bash

That's it. The command downloads the latest release, installs it as a Flatpak for your user only (no sudo, nothing layered into the system image), and starts Kase in the system tray. From then on it starts by itself at every login. Pair your AirPods in your desktop's Bluetooth settings as usual, and their battery shows up within a few seconds.

Requirements: a 64-bit PC (x86_64 or ARM64) running Linux with Flatpak and Bluetooth. KDE Plasma 6 on Wayland gets every feature; see Compatibility for the rest. If Flatpak is missing, the installer tells you the command for your distribution. It adds the Flathub remote if it's missing, because the app runs on the Freedesktop runtime from Flathub.

To	Run
Update to the latest release	the same install command again
Install a downloaded bundle	... | bash -s -- ~/Downloads/Kase.flatpak
Uninstall (app, its data and autostart)	... | bash -s -- --uninstall

Here ... stands for the curl part of the install command. The installer is a single readable script, install.sh, and you can read it before you run it. The old install-bazzite.sh link still works.

Coming from BazzitePods

Run the install command above. The installer:

1. copies your settings, saved AirPods and Flatpak overrides from io.github.dabarkle.BazzitePods to io.github.dabarkle.Kase,
2. removes BazzitePods and its old autostart entry,
3. installs and starts Kase.

Apple device mode is a system setting, so it stays as it is.

A tour

The island

The island sits at the top center of your screen, like the Dynamic Island on an iPhone. It changes shape to show what matters right now and moves on springs, the way the real thing does: it grows out of a small pill with a little bounce, its contents cross-fade, rings sweep in and percentages roll when they change. A change that arrives mid-animation bends the motion instead of restarting it.

When the AirPods connect it opens into a card with a ring for each pod and the case, then folds into a slim island with all three levels. When something happens it morphs into a short alert that names the one thing that changed:

Styles

 

• Purist (default, left) is the Dynamic Island as it really is: solid flat black with a hairline edge. When something happens, light runs round the border in that event's colour, and after under two seconds the island is still again.
• Classic (right) is smoked glass with a sheen and a soft shadow. Its Glass slider goes from the island's pure black to clear glass.

Each kind of event has its own light, so you can tell what happened from the corner of your eye:

Event	Light
The AirPods connect	a spectrum flows round the edge
Charging starts	a green sweep
A pod or the case runs low	a slow amber breath, red at 10% or below
The audio moves to or from another device	a blue sweep
Noise control changes	a ping: blue for Noise Cancellation, a spectrum for Adaptive
You swap to the AirPods mic	an orange ping, the colour iOS uses for a mic in use
The AirPods mic can't be used	a red ping and a quick shake of the head
The AirPods disconnect	a dim sweep

Behaviour in games

Pick how much of the island you want to see in the Island tab:

Mode	What you see
Compact (default)	The slim island stays on screen and opens on changes.
Pop-up	The island opens on changes, then hides.
Full	The card stays on screen, and news shows in its second line with a small bounce.
Off	Never shown.

• Four sizes. Small, Medium, Large and Extra large scale the whole island, for big or high-resolution screens.
• Six places. Click a spot on the preview screen in the Island tab to move it to any corner, or the top or bottom center.
• Opacity over games. The island turns see-through only while a fullscreen game or video is in front, and stays solid on the desktop.

Switching devices

Your PC is home. When your iPhone plays something, it gets the AirPods: Kase pauses what's playing here and the island shows Playing on iPhone, while the AirPods stay connected. A few seconds after the iPhone stops, they come back to the PC by themselves, even if you're in another room. Press play in any app on the PC, or Use on this PC in the window, and they come back straight away.

While you game, watch something or sit in a Discord call, a notification on your phone only borrows the AirPods for its sound; they're back on the PC about three seconds later. A phone call is never interrupted. If you'd rather the AirPods stay on the iPhone until you press play on the PC, as with a Mac, turn off Bring AirPods back to this PC in Settings.

When the AirPods leave the PC, for the iPhone or for the day, Kase keeps looking for them. Open the case when you get home, or just sit down and unlock the PC, and they reconnect without a trip to the Bluetooth menu.

The app window

The window has three tabs. AirPods shows a status island that glows green when the AirPods are connected and amber or red when a pod runs low, the battery rings, and on models with noise control the listening modes and conversation awareness. Island places and styles the overlay on a preview screen. Settings holds the appearance, start at login, the AirPods' own settings and Apple device mode. Light and dark follow your system, or you can pick one.

The window tells you what your AirPods are doing at a glance:

_{Connected  ·  On another device  ·  Away  ·  In the case  ·  Low battery}

A pod that drops out keeps its last level, greyed out, instead of showing 0%. The case keeps its last known level after the pods come out, marked with how long ago it was seen.

Apple device mode

AirPods behave best with devices that introduce themselves as Apple devices: they switch between them automatically and stay paired with both your iPhone and your PC. Apple device mode makes your PC's Bluetooth report Apple's vendor ID to the AirPods. It's off by default and is one switch in the Settings tab:

_{1. Flip the switch  →  2. Confirm  →  3. Enter your password}

Your system asks for your password, Bluetooth restarts, and your devices drop for a few seconds and reconnect on their own. Turn it off the same way to get your original Bluetooth settings back. No terminal needed.

What it changes, and how to do it by hand

Kase adds DeviceID = bluetooth:004C:0000:0000 under [General] in /etc/bluetooth/main.conf (keeping a one-time backup at main.conf.bak-kase) and restarts Bluetooth. If you had set a DeviceID yourself, it's commented out and restored when you turn the mode off. The script is a constant built into the app (apple_mode.rs) and runs through the standard system password prompt (pkexec), so it can never run without your password. Changes in /etc are kept across system updates (Bazzite and other image-based systems included), and your other Bluetooth devices are not affected.

To turn it on by hand:

sudo cp -a /etc/bluetooth/main.conf /etc/bluetooth/main.conf.bak-kase
sudo sed -i '/^\[General\]/a DeviceID = bluetooth:004C:0000:0000' /etc/bluetooth/main.conf
sudo systemctl restart bluetooth

To undo it by hand:

sudo sed -i '/^DeviceID = bluetooth:004C:/d' /etc/bluetooth/main.conf
sudo systemctl restart bluetooth

The AirPods mic switch

Keep your good desk mic for gaming and calls, and switch to the AirPods' mic when you walk away from the desk, without dropping the music to phone-call quality. Turn on AirPods mic switch in Settings, then:

• Hold the left stem to swap between your desk mic and the AirPods mic. A soft rising chime means the AirPods mic is on, a falling one means the desk mic is back.
• Hold the right stem to change noise control (models with noise cancellation).

Apps follow the swap on their own, including Discord and apps that use EasyEffects' mic. The PC goes back to the desk mic by itself when the AirPods go to another device, a call starts, both AirPods leave your ears, or the AirPods stop sending mic audio.

Good to know

• Music stays on high-quality AAC (where your distribution provides it: Fedora, Bazzite, Arch, SteamOS; otherwise SBC) because the AirPods send their mic over a separate stream, the way they do for an iPhone or a Mac, instead of switching to the headset profile.
• While the AirPods mic is in use, the AirPods themselves lower the music quality slightly. That happens inside the AirPods (the PC keeps sending full quality), so the mic stream only runs while the AirPods mic is selected.
• While the switch is on, stem holds belong to Kase on every device, so on an iPhone a hold won't change noise control until you turn the switch off.

The tray

The tray icon is a battery ring around a little AirPods case. It turns amber, then red, as the battery runs low, shows a bolt while charging, and greys out when the AirPods are disconnected. Closing the window keeps Kase running in the tray.

Features

Battery you can trust

• Left, right and case levels, with charging state
• Read from the AirPods' control channel while connected, and from their Bluetooth adverts while they're nearby but not connected
• Last known levels, marked with how long ago, instead of 0%
• In case when both pods are put away

The island

• Card, slim island and alerts, on springs
• Purist and Classic styles, four sizes, six places
• Translucent over fullscreen games, solid on the desktop
• Redraws only while it moves; at rest it uses no CPU

Controls

• Noise control: Noise Cancellation, Transparency, Adaptive, and optionally Off
• Conversation awareness, Personalized Volume, Adaptive Audio strength
• Automatic ear detection, which pauses and resumes your media
• Rename, microphone side, noise cancellation with one AirPod
• Stem press track control: double-press for next, triple-press for previous

Only the controls your model supports are shown.

Audio that keeps working

• Fixes "walked away, came back, connected but silent"
• Never leaves the audio card switched off, and repairs a stalled connection by itself
• Returns to AAC after a fallback codec (AAC where your distribution provides it: Fedora, Bazzite, Arch, SteamOS; otherwise SBC)
• Reconnects when the AirPods come back, however long they were away, including after a day out with your iPhone
• Disconnecting on purpose keeps them disconnected

Multiple devices

• Your PC is home: the AirPods come back a few seconds after your iPhone stops
• A phone notification never keeps them while you game, watch or talk on Discord
• Works with apps that don't report playback, such as games and the Plex desktop app
• Never interrupts a phone call
• Optional Apple device mode for Mac-like switching

Hands-off

• Starts at login, minimized to the tray
• Survives Bluetooth restarts, adapter hot-plug and suspend and resume
• Never turns Bluetooth on by itself
• Launching it again just opens the window

Compatibility

Desktops

Desktop	Island overlay	Battery and controls	Tray	Starts at login
KDE Plasma 6, Wayland (the best experience)	✅ with fullscreen transparency	✅	✅	✅
KDE Plasma 5, Wayland	✅ with fullscreen transparency	✅	✅	✅
Hyprland, Sway, niri and other wlr-layer-shell compositors	✅ with fullscreen transparency	✅	needs a tray bar (e.g. Waybar)	add flatpak run io.github.dabarkle.Kase --start-minimized to your compositor's startup (Kase shows you the line)
GNOME	Desktop notifications instead	✅	needs the AppIndicator extension (built into Ubuntu)	✅
Any desktop on X11	Desktop notifications instead	✅	✅	✅
Steam Gaming Mode (gamescope)	❌	✅	❌	from desktop mode

AirPods

Model	Battery	Noise control	Adaptive and conversation awareness
AirPods 4 with Active Noise Cancellation	✅	✅	✅
AirPods 4	✅
AirPods Pro 2 and Pro 3	✅	✅	✅
AirPods Pro (1st generation)	✅	✅
AirPods Max	✅	✅
AirPods (1st to 3rd generation)	✅

Ear detection works on every model with pods. Kase is developed and tested day to day on AirPods 4 with Active Noise Cancellation; the other models use the capability tables from LibrePods. If something doesn't look right on yours, please open an issue.

How it works

flowchart LR
    AP["AirPods"] -- "AACP over L2CAP<br/>battery, ear detection, controls, mic" --> APP
    AP -- "BLE adverts<br/>battery while not connected" --> APP
    subgraph PC["Your PC"]
        BZ["BlueZ"]
        APP["Kase<br/>tray and window"]
        OV["Island process<br/>layer-shell, click-through"]
        KW["KWin script"]
        PW["PipeWire"]
    end
    APP <--> BZ
    APP -- "state as JSON lines" --> OV
    KW -- "is a fullscreen window in front?" --> APP
    APP -- "keeps A2DP healthy, mic switch" --> PW

Loading

1. Talking to the AirPods. Kase opens Apple's private control channel (AACP) to the AirPods through BlueZ (the standard Linux Bluetooth system), the same way an iPhone does. That gives exact battery levels for each pod and the case, ear detection, noise control, device switching and the mic stream. While the AirPods are away, it decrypts their Bluetooth LE adverts instead, so you still see levels when you open the case nearby.
2. One source of truth. Everything the AirPods report goes into a single state hub. The window, tray and island all draw from it, so they never disagree.
3. The island is a separate small process on the compositor's overlay layer. It only sets up the GPU while it's visible, and redraws only while it moves.
4. Fullscreen detection. A tiny KWin script (on Plasma 5 and 6), or the compositor's window list on Sway, Hyprland and niri, tells Kase when the active window is fullscreen, so the island can turn translucent. It's a question to the window manager, not a look at the game.
5. Audio guard. Kase watches the Bluetooth audio profile and your default output. If the AirPods come back connected but silent, it renegotiates the connection and restores your output.

The design rules and module map are in ARCHITECTURE.md.

Safe with anti-cheat

The island is an ordinary desktop surface drawn by its own process on the compositor's overlay layer (wlr-layer-shell). It never touches a game:

• no Vulkan or OpenGL layers, no LD_PRELOAD, no injection or hooking
• no ptrace, and no reading other processes' memory or /proc
• no screen capture: the island never reads what's behind it
• click-through, and it never takes keyboard focus

Permissions

Kase runs in the Flatpak sandbox with only what it needs. Every permission is explained in the Flatpak manifest:

Permission	Why
Wayland (X11 as a fallback), GPU	the window and the island
PulseAudio socket	audio profile repair and the mic switch
Bluetooth, host network namespace	AACP runs on a raw Bluetooth socket, which only exists in the host's network namespace. Kase has no networking code and never talks to the internet.
BlueZ, logind, screen saver	device state, and reconnecting around suspend and when you come back to the PC
KWin, tray, notifications, MPRIS	fullscreen detection, the tray icon, alerts on GNOME, pausing media
Flatpak host commands	Apple device mode's single fixed script, behind your password

No file system access, no full session or system bus.

Troubleshooting and FAQ

The battery doesn't show up

Make sure the AirPods are paired and connected in your desktop's Bluetooth settings, and that Kase is running (look for its icon in the tray, or open it from the app menu). Kase finds paired AirPods by itself; there is nothing to set up in the app.

The case level is old or missing

That's how AirPods work: the case reports its level only while at least one pod is inside it with the lid open, the same as on an iPhone. Kase keeps the last reading and shows how long ago it was seen. Open the lid near the PC to update it.

If levels are slow to update while the AirPods aren't connected to the PC, turn on Quicker battery updates when not connected in Settings → Diagnostics. It switches on a newer Linux Bluetooth feature that's still labelled experimental, and Bluetooth restarts for a few seconds when you change it.

I don't see the island

Check that In games isn't set to Off in the Island tab, and press Show on screen to test it. The island needs a compositor with wlr-layer-shell, such as KDE Plasma or Hyprland. On GNOME you get desktop notifications instead, and Steam Gaming Mode has no overlay layer for apps.

The AirPods are connected but there's no sound

Kase repairs this by itself within a few seconds. If it doesn't, attach Kase's log, ~/.var/app/io.github.dabarkle.Kase/.local/state/kase/kase.log, to an issue. For more detail, run it with debug logging:

flatpak kill io.github.dabarkle.Kase
flatpak run io.github.dabarkle.Kase --debug 2>&1 | tee ~/kase-debug.log

The window or island is blank, flickers or won't open (NVIDIA, older GPUs)

Kase draws with Vulkan by default. If your GPU or driver has trouble with that, switch it to OpenGL, or to software drawing, then restart Kase:

flatpak override --user --env=WGPU_BACKEND=gl io.github.dabarkle.Kase       # OpenGL
flatpak override --user --env=ICED_BACKEND=tiny-skia io.github.dabarkle.Kase  # software, no GPU needed

On NVIDIA, also check that the Flatpak GL extension matches your driver: flatpak list | grep nvidia should show the same version as nvidia-smi. If not, run flatpak update.

On a laptop with two GPUs, pick which one Kase uses with flatpak override --user --env=WGPU_POWER_PREF=low io.github.dabarkle.Kase (the power-saving one) or =high (the fast one). Undo any of these with flatpak override --user --reset io.github.dabarkle.Kase.

Does it work in Steam Gaming Mode?

Battery, controls, audio repair and switching work wherever Kase runs, but gamescope has no overlay layer for other apps, so the island is a desktop-mode feature.

Can my AirPods get banned or my games flagged?

No. Kase talks to the AirPods the way an iPhone does, and the island never touches a game. See Safe with anti-cheat.

Development

Kase is written in Rust with iced for the interface, bluer for Bluetooth and libpulse for audio. It lives in linux-rust/.

cd linux-rust
cargo build --release   # builds the app (kase) and the island (kase-overlay)
cargo test              # no Bluetooth, AirPods, sound server or display needed (or: just test)
just flatpak            # builds and installs the Flatpak

Building needs Rust, pkg-config and the development files for D-Bus, PulseAudio, xkbcommon, Wayland and libavcodec:

Distribution	Packages
Fedora	sudo dnf install gcc pkgconf-pkg-config dbus-devel pulseaudio-libs-devel libxkbcommon-devel wayland-devel ffmpeg-free-devel
Arch	sudo pacman -S base-devel pkgconf dbus libpulse libxkbcommon wayland ffmpeg
Ubuntu / Debian	sudo apt install build-essential pkg-config libdbus-1-dev libpulse-dev libxkbcommon-dev libwayland-dev libavcodec-dev

Project layout

Path	What's there
src/main.rs, src/lib.rs	the kase program's arguments, and the library everything else lives in
src/supervisor.rs	starts the services and runs one AirPods session at a time
src/bluetooth/	AACP (the AirPods control protocol) and LE advert decryption
src/devices/	the AirPods session: handshake, reconnect, device switching
src/core/	battery rules and the AirPods model table
src/hub.rs	the single state hub everything draws from
src/audio/	the audio guard (A2DP health, codec, default output)
src/mic/	the AirPods mic: stream decoding, virtual mic, switching, chimes
src/ui/	the window, tray, springs and styles
src/bin/kase-overlay/	the island: shapes, springs, purist shader, alerts
flatpak/, packaging/	Flatpak manifest, app metadata and the installer

Previewing the UI without AirPods

Both binaries have demo modes with fake AirPods, which is how the screenshots here are made:

kase --ui-demo pro                               # also: airpods4, max, low, elsewhere, disconnected, incase, putaway, empty, btoff
KASE_UI_TAB=island kase --ui-demo                # open on a given tab: airpods, island or settings
kase-overlay --demo-story --style purist         # a scripted tour of every island state
kase-overlay --demo --step 3 --size extra_large  # one sample state, at a given size

Testing. Every pull request runs the full test suite with a coverage floor and builds the Flatpak. Hardware test steps for a release are in TESTING.md, and every change is listed in the changelog.

Contributing. Bug reports, ideas and pull requests are welcome in issues. For code changes, please keep to the hard rules at the top of ARCHITECTURE.md and add tests next to the module you change.

Acknowledgements

Kase stands on LibrePods by Kavish Devar and the LibrePods contributors, who reverse-engineered Apple's AirPods protocol. The AACP implementation, the LE advert decryption and the Rust Bluetooth groundwork come from LibrePods. Kase builds a new desktop app around them: the island, the window and tray, the battery and audio logic, device switching, the mic switch and the packaging. The AirPods mic stream follows the approach found in LibrePods pull request #655.

This repository is a fork of LibrePods, trimmed to the Kase desktop app in linux-rust/. LibrePods' notes on the AirPods protocol live on in linux-rust/docs/protocol/. Upstream's original branches are kept as upstream-main and linux/rust.

The interface uses the Inter typeface (SIL Open Font License).

Licence

Kase: AirPods for Linux
Copyright © 2025 LibrePods contributors
Copyright © 2026 Kase contributors

This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, version 3 of the License. It is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for details.

Kase is not affiliated with, endorsed by or sponsored by Apple Inc. or KDE e.V. AirPods, iPhone and Mac are trademarks of Apple Inc. KDE and Plasma are trademarks of KDE e.V. All other trademarks belong to their respective owners.