SpacialShell

material-shell's spatial desktop, on the Mac. A tiling window manager for macOS where every window has one address, you move by direction, and the shell remembers where you put things.

Get started

brew install --cask askalice/tools/spacialshell

Launch it, grant Accessibility when asked, and press Fn+S. Hold Fn on its own for a cheat sheet of every binding. More in Install.

Why it exists

Your brain is already a very good window manager, if you give it a place to work with. Spatial memory is how you know where the mugs are in your own kitchen; mental mapping is how you plan a route through a place you know. A pile of overlapping windows gives neither anything to hold on to. A stable grid gives them everything.

So SpacialShell lays your apps out in two dimensions — every workspace is a row, every window a cell — grouped by use case: browsers on one row, editor and terminal on the next, media below. It remembers that arrangement as you use it, with nothing to configure. You move by direction, like in a game world: Fn+W/Fn+S between rows, Fn+A/Fn+D along one. And the rail and tab bar show the whole map at a glance, so the mouse works as well as the keyboard. Finding a window stops being a search and becomes wayfinding.

This is the paradigm of GNOME's material-shell and its successor Veshell — a "not-desktop" you inhabit rather than tidy. SpacialShell is that lineage rebuilt for macOS, not Linux: not a port and no shared code, under the same GPL-3.0.

Built on Apple's terms

Both of those projects own the compositor. On a Mac nobody does, which shapes everything here:

• The public Accessibility API instead of a compositor — the same interface screen readers use.
• Screenshot-proxy animations — switches slide pictures of the windows, then move the real ones once, because macOS has no hooks for animating another app's window.
• Beside Spaces, fullscreen and the menu bar, not replacing them; an app can't drag you out of a fullscreen Space by stealing focus.
• No private APIs, SIP stays on — nothing to reinstall after a macOS update.
• Notarised, outside the App Store — the App Store sandbox forbids the control a tiler needs.
• Native look — vibrancy materials, your accent colour, light/dark from System Settings.

Live captures

Recorded in the test VM (one 1024×768 display) while a scenario drives the real shell through spacialctl and synthetic input: Scripts/e2e/e2e.sh --vm --suite media, then Scripts/e2e/media.sh. Multi-display features aren't in these; they need a real multi-monitor Mac.

The model

A workspace is a row; an application window is a cell. New windows append to the current row, new workspaces append underneath. Up/down changes workspace, left/right changes window. The screen is a viewport over a larger, always-sorted grid, and the spatial view shows that grid: Fn+Z, or holding Fn+W / Fn+S, zooms out to every workspace as a mini-desktop, drawn from the model, with the camera sliding between rows as you move.

• Single address. Every managed window lives in exactly one workspace of exactly one display.
• There's always a way down. Each display's stack ends with one empty workspace; empty rows in the middle disappear on their own.
• Per-display stacks. Every display has its own rail; a window (Fn+⇧+arrows) or a whole workspace (Fn+⌥⇧+arrows) can move to the display that way.
• Categories are identity. The rail shows what each row is — web, terminal, coding, media — and category-order gives each category its own row, so a new browser window lands with the other browsers.
• Placement memory. Windows go back to their workspace and display across restarts (displays matched by UUID) — into their own tab slot: a window whose app has not reopened it waits as a placeholder tab that opens the app when clicked — and nothing is ever left invisible: every window the shell lists is one click away, and parked windows are recovered after a crash.

Interface and layouts

• The rail (left): one row per workspace with its apps and category, hover previews, a tray for hidden and minimized windows, right-click menus (quit an app, set a row's category), scroll to switch, and Dock-style auto-hide.
• The tab bar (top): a tab per window, drag to reorder or onto a rail row, right-click for Close / Float / Move to workspace, middle-click to close; plus the layout switcher.
• Layouts: Fn+Space cycles maximize · split (an N-column sliding view) · column · half · grid. Draw your own in the layout editor or as [[layout]] blocks.
• Resize: drag a border, or Fn+⌃A/D/W/S in 5% steps that stop on 25/50/75%; Fn+⌃= balances. Sizes are kept per workspace and per layout.
• Hold Fn for the cheat sheet, Fn+Tab for the overview, Fn+Esc for Zen mode.

Hotkeys

Fn/Globe is the default modifier; ⌃⌥ is the preset for keyboards without a Globe key (keybinding-preset = "ctrl-alt"). The grammar: Fn navigates, +⇧ moves the window, +⌃ resizes, +⌥ reaches displays or the whole app.

Command	fn preset	ctrl-alt preset
Focus workspace up / down	Fn+W / Fn+S	⌃⌥W / ⌃⌥S
Focus window left / right	Fn+A / Fn+D	⌃⌥A / ⌃⌥D
Focus workspace 1…10 (again to go back)	Fn+1 … Fn+0	⌃⌥1 … ⌃⌥0
Focus tab 1…9	Fn+⌥1 … Fn+⌥9	—
Move window left / right	Fn+⇧A / Fn+⇧D	⌃⌥⇧A / ⌃⌥⇧D
Move window to workspace up / down / N	Fn+⇧W / Fn+⇧S / Fn+⇧1…0	⌃⌥⇧W / ⌃⌥⇧S / —
Move every window of the app up / down	Fn+⌥⇧W / Fn+⌥⇧S	—
Resize narrower / wider / shorter / taller	Fn+⌃A / D / W / S	⌃⌥⌘A / D / W / S
Balance sizes	Fn+⌃=	⌃⌥⌘=
Focus display that way	Fn+⌥W/A/S/D	—
Move window / workspace to display that way	Fn+⇧+arrows / Fn+⌥⇧+arrows	—
Focus / move to display prev, next	Fn+[ Fn+] / Fn+⇧[ Fn+⇧]	⌃⌥[ ⌃⌥] / ⌃⌥⇧[ ⌃⌥⇧]
Cycle layout / backwards	Fn+Space / Fn+⇧Space	⌃⌥Space / ⌃⌥⇧Space
Toggle float	Fn+G

Fn+F is deliberately unbound — Globe+F is Apple's full-screen shortcut. Every chord can be rebound in config.toml or Settings; see docs/keybindings.md.

Install

1. brew install --cask askalice/tools/spacialshell, or download the notarised DMG from Releases and move SpacialShell.app to /Applications. Keep it where you put it: moving it invalidates the Accessibility grant.
2. Launch it. It asks for Accessibility and opens System Settings → Privacy & Security → Accessibility; tick SpacialShell and it continues on its own.
3. Optional: hover previews and sliding switches need Screen Recording; the hover card offers it when it matters. Restart SpacialShell after granting it. Without it, switches are instant and everything else works.
4. Quit from the rail's app menu. Quitting restores every managed window to the centre of its screen and saves your layout.

Build from source

Requires macOS 14+ and a Swift 6 toolchain (Xcode 16 or later).

git clone https://github.com/AskAlice/SpacialShell-MacOS.git && cd SpacialShell-MacOS
swift test          # the gate for every change
Scripts/dev.sh      # build debug and run in the foreground
Scripts/bundle.sh   # build/SpacialShell.app, signed with a stable identity

Scripts/dev.sh runs the raw binary, whose Accessibility grant is tied to its path; see Scripts/README for the TCC details and SPACIAL_LOG_KEYS=1 for hotkey debugging. make hooks installs the pre-commit hook. CONTRIBUTING.md has the rest.

Known limitations

• One native macOS Space per display. Workspaces are emulated by parking inactive windows, not by native Spaces, so Mission Control and ⌘Tab can still see parked windows.
• Non-Apple keyboards never send Fn. Use the ctrl-alt preset or Karabiner-Elements.
• Some Fn+letter chords collide with macOS's own shortcuts. The keyboard hook runs at the HID level to win that race; see docs/keybindings.md for known conflicts.

Licence and attribution

SpacialShell is licensed under the GNU General Public License v3.0 (GPL-3.0) — see LICENSE.

Its Accessibility/platform layer adapts MIT-licensed code from AeroSpace (Copyright (c) 2023 Nikita Bobko); the licence ships in legal/third-party/LICENSE-AeroSpace.txt, every adapted file carries an attribution header, and NOTICE lists them all. The spatial paradigm is design inspiration from material-shell and Veshell (both GPL-3, like SpacialShell); no code from either was used.

The Raycast extension in raycast/ is MIT-licensed, as the Raycast Store requires of every extension.