Slipmat

A native GNOME client for Apple Music.

Apple ships no Linux client, and the DRM makes a fully native one impossible — so Slipmat draws its own interface in GTK4 and libadwaita, written in Rust, and keeps the web engine strictly for decoding audio. Real lists, real GNOME search, and media controls that answer from the top bar and the lock screen.

The web engine is still there. You just never see it.

What it does

A native GNOME app. GTK4 and libadwaita, written in Rust — real lists, real keyboard navigation, a window that tiles to half a screen. There is a web layer, because Apple's DRM leaves no choice, but it is one hidden process that decodes audio and nothing else. You never see a web page.

Your library. Songs, albums, artists and playlists, each with type-to-find filtering and its own sorting. Click anything and the list you are looking at becomes the queue.

A player worth the name. Gapless, with a full-size view you can pull up, the queue beside it, and the cover behind it.

Controls where you already look. Play, pause and skip from the GNOME top bar, from the lock screen, or with your keyboard's media keys — cover and title alongside them, and the position honest while it plays. Close the window and the music keeps going; it quits when you tell it to, not when you tidy your desktop.

All of Apple Music, searchable. Artists, albums, playlists and songs in one list, paginated as you scroll, each opening a page you can play from and drill through.

Quick, and out of the way. It opens on your library rather than on a spinner, a five-hundred-track list scrolls without stuttering, and whatever you were playing is waiting next launch — restored, never resumed. An app that starts making noise because you opened it is a hostile one.

Albums, sidebar collapsed		Artists, portraits from the catalogue		A playlist — cover built from its tracks
The player opened out, queue alongside			Searching the whole catalogue

Install

You need an active Apple Music subscription, an x86_64 machine (Widevine on Linux is x86_64 only), and a network connection every time you play — that last one is permanent, not a limitation we intend to lift. See Limitations.

Every route fetches castLabs Electron once — about 200 MB of Chromium. That is the Widevine boundary and there is no smaller version of it.

Arch and derivatives

Both packages are on the AUR:

yay -S slipmat        # the latest release
yay -S slipmat-git    # tracks main

They conflict with each other, as the convention requires. slipmat-git rebuilds from whatever is on main, so it picks up unreleased work — including anything half-finished.

Flatpak — any distribution

Slipmat needs libadwaita ≥ 1.8 and GTK ≥ 4.20, which rules out Debian stable, Ubuntu 24.04 and Fedora ≤ 42. The Flatpak carries the GNOME 49 runtime with it, so your system's libadwaita stops mattering — verified from nothing on a stock Ubuntu 25.10, which cannot build Slipmat at all.

Download Slipmat.flatpak from the latest release, then:

flatpak install ./Slipmat.flatpak
flatpak run dev.miguelrincon.Slipmat

A bundle carries the app and not the runtime it sits on, so the install offers to fetch GNOME 49 from Flathub the first time. Answer yes, or it stops with "requires the runtime org.gnome.Platform/x86_64/49 which was not found". If your machine has no Flathub remote at all:

flatpak remote-add --if-not-exists --user flathub \
  https://dl.flathub.org/repo/flathub.flatpakrepo

It is not on Flathub and is not intended to be.

From source

sudo pacman -S --needed base-devel pkgconf rust gtk4 libadwaita librsvg nodejs npm
make install     # build + install to ~/.local, no sudo

Also needs Rust ≥ 1.93 (relm4 0.11's MSRV) and Node — verified on Node 26. Then launch Slipmat from the app grid, or run slipmat. If that command is not found, ~/.local/bin is not on your PATH.

First run

Apple's own sign-in window opens once, and hides for good after you authenticate. Notifications need the app to be installed — running from a build tree, the shell has no .desktop entry to attach them to.

Support

Slipmat is free, GPL-3, and stays that way. It is also a spare-time project for one Linux laptop that other people happen to find useful.

If it earns a place on yours:

Limitations

These are properties of the platform, not a to-do list:

• No offline or downloaded playback. Linux's Widevine CDM does not support persistent licences (it reports PLATFORM_UNVERIFIED), so every track must be licensed live. Slipmat cannot work on a plane.
• ~200 MB on disk for the sidecar. It is a full Chromium. That is the cost of the only CDM that exists.
• x86_64 only. No ARM Widevine on Linux.
• Apple can change music.apple.com. The hook that drives MusicKit is small and defensive, but it is the one surface outside our control. If Apple moves something, Slipmat says so rather than silently spinning.
• A few library tracks may be unplayable. Apple delists tracks while leaving them in your library. Slipmat finds them on first attempt, remembers them across sessions, and dims them rather than letting one break a queue.

Known bugs live in the issue tracker.

How it works, honestly

Apple Music full tracks are HLS + Widevine DRM. On Linux the only Widevine CDM that exists is the one Google ships inside Chromium. There is no way around that — WebKitGTK has no CDM, and GStreamer cannot decrypt the stream. A 100% native Apple Music player cannot be built.

So Slipmat splits the problem:

┌──────────────────────────────────────────────────┐
│  Slipmat — Rust · relm4 · libadwaita             │  ← everything you see
│  library · search · queue · Now Playing          │
│  MPRIS · notifications · media keys · artwork    │
│  HTTPS ─────────────────► api.music.apple.com    │
└───────────────────────┬──────────────────────────┘
                        │  newline-delimited JSON over stdio
┌───────────────────────▼──────────────────────────┐
│  sidecar — castLabs Electron                      │  ← invisible after login
│  hidden music.apple.com  +  MusicKit  +  Widevine │
│  → audio straight to PipeWire, untouched          │
└───────────────────────────────────────────────────┘

All browsing, search and metadata is native code talking to Apple's REST API and drawing native widgets. Only the audio decode happens in the sidecar — a Chromium window with show: false, displayed exactly once for Apple's own sign-in and then never again. It is never rendered, it does not appear in the dash, and it does not publish an MPRIS player of its own.

Slipmat plays through Apple's own MusicKit player with Google's official CDM. It is a native front-end and a remote control for a licensed session. It does not strip DRM, does not use extracted CDMs, and does not download anything.

Development

cargo run                                    # dev
RUST_LOG=slipmat=debug cargo run             # trace the sidecar protocol
make sidecar-run                             # sidecar alone, window VISIBLE
make gapless                                 # watch the audio stream across a boundary
cargo clippy --all-targets -- -D warnings    # the bar
make check                                   # fmt + clippy + test

Debug in layers — make sidecar-run first. If a track won't play with the window visible, the problem is DRM or Apple, not Rust.

The module headers in src/ say what each file is for, the long comments are the traps and the measurements behind them, and the merged PRs carry the reasoning for each change.

Related

Prior art worth crediting: Sidra and Cider worked out the castLabs Electron path first, which is what makes any of this possible on Linux. They take a different approach to the interface; Slipmat would not exist without the groundwork.

Licence

GPL-3.0-or-later. See COPYING.