alttab

A fast alt-tab window switcher for Wayland compositors (targeting Sway). Behaves like Windows/macOS alt-tab: a small overlay lists open windows sorted by most-recently-used order, hold Alt and press Tab to cycle, release Alt to switch.

Single Rust binary, ~2.8MB stripped. Zero runtime dependencies beyond Wayland.

Disclaimer: This application was fully generated by AI (Claude). The entire codebase — architecture, implementation, and documentation — was produced through AI-assisted development.

Features

• MRU window switching — Windows sorted by most-recently-used order, not workspace order
• Daemon architecture — Long-lived process tracks focus changes over time for accurate MRU history
• Multi-monitor aware — Overlay appears on the same monitor as the focused window
• Window icons — Loads PNG icons from desktop files and icon themes (hicolor)
• Configurable — Colors and layout customizable via TOML config file
• Proper font rendering — Embedded DroidSans TTF font rendered with fontdue (supports full Unicode)
• Fast — Software rendering with tiny-skia, no heavy GUI toolkit dependencies
• Lightweight — ~2.8MB stripped, single binary with embedded font

Requirements

• Sway (or any wlroots-based Wayland compositor with wlr-foreign-toplevel-management and wlr-layer-shell support)
• libxkbcommon and wayland client libraries (runtime)

Build dependencies

Building from source (including cargo install) requires development headers for libxkbcommon and wayland:

Fedora:

sudo dnf install libxkbcommon-devel wayland-devel

Debian/Ubuntu:

sudo apt install libxkbcommon-dev libwayland-dev

Arch Linux:

sudo pacman -S libxkbcommon wayland

Install

From crates.io

cargo install alttab

From source

git clone https://github.com/e-gautier/alttab.git
cd alttab
cargo build --release
# Binary is at target/release/alttab

Usage

1. Start the daemon

alttab &

This starts a background daemon that connects to Wayland and continuously tracks window focus changes to build MRU history.

2. Configure Sway keybinding

Add to ~/.config/sway/config:

bindsym Alt+Tab exec /path/to/alttab --show

Now press Alt+Tab to bring up the switcher. Keep holding Alt and press Tab to cycle through windows. Release Alt to switch to the selected window.

Keyboard shortcuts

Key	Action
Tab / Down / Right	Select next window
Shift+Tab / Up / Left	Select previous window
Enter	Confirm and switch
Escape	Cancel
Release Alt	Confirm and switch

Configuration

Config file: ~/.config/alttab/config.toml

All fields are optional — missing fields use sensible defaults.

[colors]
background = "#1E1E1EE6"
item = "#323232FF"
selected = "#3C78D8FF"
title = "#FFFFFFFF"
app_id = "#AAAAAAFF"

[layout]
width = 500
max_height = 600
item_height = 48
item_spacing = 8
padding = 16
corner_radius = 12.0
item_corner_radius = 8.0

Colors

Hex format: #RRGGBB (opaque) or #RRGGBBAA (with alpha).

Field	Description	Default
background	Overlay background	#1E1E1EE6 (dark, semi-transparent)
item	Unselected item background	#323232FF
selected	Selected item highlight	#3C78D8FF (blue)
title	Window title text	#FFFFFFFF (white)
app_id	App ID text below title	#AAAAAAFF (gray)

Layout

Field	Description	Default
width	Overlay width in pixels	500
max_height	Maximum overlay height	600
item_height	Height of each window entry	48
item_spacing	Space between entries	8
padding	Inner padding	16
corner_radius	Overlay corner radius	12.0
item_corner_radius	Item corner radius	8.0

Themes

Copy any of these [colors] sections into your ~/.config/alttab/config.toml.

Default (Dark)

The built-in theme. Dark background with a blue selection highlight.

[colors]
background = "#1E1E1EE6"
item = "#323232FF"
selected = "#3C78D8FF"
title = "#FFFFFFFF"
app_id = "#AAAAAAFF"

Nord

Inspired by the Nord color palette. Cool, arctic tones.

[colors]
background = "#2E3440E6"
item = "#3B4252FF"
selected = "#5E81ACFF"
title = "#ECEFF4FF"
app_id = "#D8DEE9AA"

Catppuccin Mocha

Inspired by Catppuccin Mocha. Warm pastel tones on a dark base.

[colors]
background = "#1E1E2EE6"
item = "#313244FF"
selected = "#89B4FAFF"
title = "#CDD6F4FF"
app_id = "#A6ADC8AA"

Gruvbox Dark

Inspired by Gruvbox. Retro, warm, earthy tones.

[colors]
background = "#282828E6"
item = "#3C3836FF"
selected = "#D65D0EFF"
title = "#EBDBB2FF"
app_id = "#A89984AA"

Dracula

Inspired by Dracula. Purple-accented dark theme.

[colors]
background = "#282A36E6"
item = "#44475AFF"
selected = "#BD93F9FF"
title = "#F8F8F2FF"
app_id = "#6272A4FF"

Solarized Dark

Inspired by Solarized. Precision-engineered color scheme.

[colors]
background = "#002B36E6"
item = "#073642FF"
selected = "#268BD2FF"
title = "#FDF6E3FF"
app_id = "#839496AA"

Tokyo Night

Inspired by Tokyo Night. Muted blues and purples.

[colors]
background = "#1A1B26E6"
item = "#24283BFF"
selected = "#7AA2F7FF"
title = "#C0CAF5FF"
app_id = "#565F89FF"

Rosé Pine

Inspired by Rosé Pine. Muted, elegant tones.

[colors]
background = "#191724E6"
item = "#1F1D2EFF"
selected = "#C4A7E7FF"
title = "#E0DEF4FF"
app_id = "#908CAAAA"

Kanagawa

Inspired by Kanagawa. Japanese ink painting aesthetic.

[colors]
background = "#1F1F28E6"
item = "#2A2A37FF"
selected = "#7E9CD8FF"
title = "#DCD7BAFF"
app_id = "#727169AA"

Monochrome

Minimal grayscale. No color distractions.

[colors]
background = "#181818E6"
item = "#282828FF"
selected = "#585858FF"
title = "#E8E8E8FF"
app_id = "#888888AA"

How it works

The wlr-foreign-toplevel-management Wayland protocol only reports current window state at connection time — it has no historical activation order. A fresh process on each Alt+Tab would see all windows but wouldn't know which was used most recently.

To solve this, alttab runs as a daemon that stays alive and watches activation state transitions over time, building real MRU history. When triggered via alttab --show, the daemon creates a layer-shell overlay with exclusive keyboard grab and renders the window list using software rendering into shared memory buffers.

Known limitations

• PNG icons only — SVG/scalable icons are not supported
• Nearest-neighbor icon scaling — Fast but not the highest quality
• Sway/wlroots only — Requires wlr-foreign-toplevel-management and wlr-layer-shell protocols (not available on GNOME/KDE Wayland)

License

MIT — see LICENSE.

The embedded DroidSans font is licensed under the Apache License 2.0 (Copyright 2008 The Android Open Source Project) — see fonts/LICENSE-DroidSans.