Voltkit

Power tools for your Linux desktop. Screen OCR, a QR code scanner, a color picker, a screen ruler, an image & video compressor, a text expander, Keep Awake and a hosts & environment editor, in one app.

One app instead of eight

Getting these basics on Linux usually means hunting down a separate applet for each job, each with its own look, settings and shortcuts. Voltkit puts them in one native GTK4 app with one set of hotkeys:

Instead of…	Voltkit gives you	Shortcut
a separate OCR app	Text Extractor: drag a box around any text on screen, even in videos and images, and it lands on your clipboard	Super+Shift+T
a separate color picker	Color Picker: an eyedropper for any pixel, HEX/RGB/HSL, WCAG contrast check and history	Super+Shift+C
a QR scanner on your phone or a QR website	QR Code: read a QR code anywhere on screen, or turn text, links and Wi-Fi details into one	Super+Shift+Q
a separate screen ruler, or screenshots and an image editor	Screen Ruler: freeze the screen and measure anything in pixels	Super+Shift+R
a separate image compressor, plus ffmpeg incantations	Asset Compressor: drop PNG, JPEG, WebP or MP4 files to strip metadata and shrink them	drag & drop
a separate text expander	Text Expansion: a searchable snippet picker, plus optional typed triggers like ;date	Super+Shift+E
a shell extension to keep the screen on	Keep Awake: stop your computer from sleeping or locking for 30 minutes to 4 hours, or until you turn it off	—
editing /etc/hosts and ~/.profile in a terminal	Hosts & Environment: switch hosts entries on and off, and manage your session's environment variables	—

Features

🔍 Copy text from anything on screen

A Wi-Fi password on a conference slide, a command in a video tutorial, an error in a screenshot: press Super+Shift+T, drag a box, and paste. Powered by Tesseract, with support for 100+ languages.

🎨 Pick, convert and check colors

Grab any pixel with Super+Shift+C and the HEX code is already on your clipboard. The color page converts between HEX, RGB and HSL, rates contrast against white and black by WCAG standards (AA / AAA), and remembers your recent colors.

📦 Shrink images and videos in one drop

Drop files on the window or run voltkit compress. Voltkit strips location data and other metadata, compresses with the best tool for each format, and writes name.min.ext next to the original, which it never touches. In our tests: JPEG −43%, PNG −23% (lossless), WebP −60%, MP4 −77%.

⌨️ Type less with snippets

Press Super+Shift+E, search, press Enter, and the snippet is pasted into whatever app you were using. Snippets can include the date in any format, your clipboard, and fill-in-the-blank fields. Prefer typing? Turn on typed triggers and ;sig becomes your signature in any app. Add, edit and delete snippets right in the app: Insert buttons add the date, time, clipboard or a fill-in field, and a live preview shows exactly what will be pasted.

📷 Read and make QR codes

Press Super+Shift+Q and drag a box around a QR code in a video, a slide or a web page: its text or link is on your clipboard. Going the other way, type a link, some text or your Wi-Fi details and scan the code with your phone. Copy it as an image or save it as a PNG to print. Add your own small logo to the middle if you like: Voltkit reads the code back to make sure it still scans.

📏 Measure anything on screen

Super+Shift+R freezes the screen. Drag to measure widths and heights in real pixels (hold Shift for a straight line), and press Ctrl+C to copy the size.

☕ Keep your computer awake

Watching, presenting or downloading? Turn on Keep Awake for 30 minutes, a few hours or until you turn it off, and your computer won't sleep or lock. It keeps going after you close Voltkit and switches itself off when the time is up.

📝 Edit hosts and environment variables without a terminal

Switch /etc/hosts entries on and off, add myapp.test → 127.0.0.1 for local development, and set environment variables like EDITOR or an extra PATH folder for your whole desktop session. System entries are protected, and every hosts save keeps a backup.

Why Voltkit

• Built for Wayland. It uses the desktop's own portals for screenshots, the eyedropper and pasting, so there are no X11 hacks and no shell extensions.
• Private by design. Everything runs locally, with no network access and no telemetry. Typed triggers keep only the last few characters in memory and never log or store what you type.
• Small and native. One 4 MB binary (a 1.4 MB package), GTK4 + libadwaita, light and dark mode.
• Scriptable. Every feature is also a command (voltkit ocr, voltkit color '#3584e4', voltkit compress *.jpg), with man pages for all of them.
• Self-checking. voltkit doctor tells you exactly what's missing and the command to install it.
• Signed packages. Install and update through apt from a GPG-signed repository.

FAQ

Does it work on KDE, Sway or Hyprland? Voltkit is developed and tested on GNOME (Zorin OS 18). It uses standard XDG portals, so KDE Plasma and other desktops should work, but they haven't been tested yet. Reports are welcome! On desktops without the GlobalShortcuts portal, bind voltkit trigger ocr|color|snippets to keys yourself.

Is it safe to turn on typed triggers? They're off by default. Wayland hides keystrokes between apps, so typed triggers need access to the keyboard device, which you grant once with voltkit expander setup. The snippet picker works without any of that.

Why isn't there a Flatpak? It's on the roadmap. For now there's the apt repository for Ubuntu/Debian-based systems, and building from source works anywhere with GTK 4.14+.

Screenshots taken on Zorin OS 18 with its ZorinBlue theme. Regenerate them with docs/screenshots/capture.sh.

Install (Ubuntu, Debian and derivatives)

For Ubuntu 24.04+, Debian 13+, Linux Mint 22, Zorin OS 18, Pop!_OS 24.04 and other derivatives on 64-bit Intel/AMD:

sudo curl -fsSLo /usr/share/keyrings/voltkit-archive-keyring.gpg \
  https://arios4k.github.io/voltkit/voltkit-archive-keyring.gpg
echo "deb [signed-by=/usr/share/keyrings/voltkit-archive-keyring.gpg] https://arios4k.github.io/voltkit stable main" \
  | sudo tee /etc/apt/sources.list.d/voltkit.list
sudo apt update && sudo apt install voltkit

apt installs the required tools (Tesseract, wl-clipboard, the desktop portal) along with Voltkit, and updates arrive with sudo apt upgrade. Then:

voltkit doctor                    # check everything is in place
voltkit shortcuts install         # GNOME: Super+Shift+T, C and E
voltkit daemon enable-autostart   # start the background service at login

PNG compression needs oxipng, which Ubuntu doesn't package: cargo install oxipng.

Install (from source)

Requirements: Rust 1.85+, GTK ≥ 4.14, libadwaita ≥ 1.5.

# Debian/Ubuntu
sudo apt install libgtk-4-dev libadwaita-1-dev
# Fedora
sudo dnf install gtk4-devel libadwaita-devel
# Arch
sudo pacman -S gtk4 libadwaita

cargo install --path .     # installs to ~/.cargo/bin/voltkit
voltkit

Install the binary before you set up shortcuts or autostart: both record the binary's path.

To add Voltkit to your app grid with its icon:

install -Dm644 data/icons/io.github.arios4k.Voltkit.svg ~/.local/share/icons/hicolor/scalable/apps/io.github.arios4k.Voltkit.svg
install -Dm644 data/icons/io.github.arios4k.Voltkit-symbolic.svg ~/.local/share/icons/hicolor/symbolic/apps/io.github.arios4k.Voltkit-symbolic.svg
sed "s|^Exec=voltkit|Exec=$HOME/.cargo/bin/voltkit|" data/io.github.arios4k.Voltkit.desktop > ~/.local/share/applications/io.github.arios4k.Voltkit.desktop

Background service & global shortcuts

voltkit daemon                    # run in the foreground
voltkit daemon enable-autostart   # start at every login
voltkit daemon status             # running? which shortcut backend?
voltkit daemon stop

The daemon owns io.github.arios4k.Voltkit.Daemon on the session bus, so only one runs at a time. It binds the hotkeys from your config in one of these ways:

Desktop	How the hotkeys are bound
GNOME 48+, KDE Plasma 5.27+, Hyprland (xdg-desktop-portal ≥ 1.19)	GlobalShortcuts portal: the desktop asks you to approve them once
Older GNOME (e.g. 46) and GNOME-based distros	voltkit shortcuts install adds them to Settings → Keyboard → Custom Shortcuts (--dry-run previews; shortcuts remove undoes)
Sway, river, others	Bind voltkit trigger ocr / voltkit trigger color in your compositor config

voltkit trigger <action> (ocr, color or snippets) sends the action to the running daemon, or runs it directly if no daemon is running. Results and errors appear as desktop notifications.

Text expansion

Managing snippets: on the Text Expansion page, use Add Snippet, click a snippet to edit it, or delete it (with Undo). Changes are saved to ~/.config/voltkit/config.toml and reach typed triggers immediately. If you edit that file by hand, run voltkit daemon reload.

Snippet picker (no setup): press Super+Shift+E, type to search, press Enter. Snippets with {arg:NAME} parameters show a small form. The result is pasted into the app you were using, and your clipboard is put back afterwards. The first paste asks for remote-desktop permission (that's how Wayland lets an app press Ctrl+V for you), and the permission is remembered.

Typed triggers (opt-in): type ;date in any app and it turns into 2026-10-27. Wayland hides keystrokes from other apps, so this needs a one-time root setup:

voltkit expander setup          # shows the commands and what they change
voltkit expander setup --apply  # runs them with sudo; then log out and back in
                                   # (restart instead if `loginctl` lingering is on)
voltkit expander enable

Setup adds you to the input group, which lets any program you run read keyboard input. Voltkit keeps only the last few characters in memory and never logs or stores what you type. See man voltkit-expander for details and how to undo it.

For terminals, which paste with Ctrl+Shift+V, set paste_shortcut in the [expander] config section.

Runtime helpers

Voltkit calls standard tools when they are installed, so it adds no heavy dependencies of its own. Check what's missing, with the install command for your distro, at any time:

voltkit doctor

The control center shows a banner when a feature needs attention.

Feature	Tools
OCR	tesseract (+ language packs such as tesseract-ocr-eng)
Region capture, eyedropper	the desktop's Screenshot portal; region capture falls back to grim+slurp, gnome-screenshot, spectacle or maim
Clipboard (daemon, CLI)	wl-clipboard (Wayland) or xclip (X11). Without it, the result is still shown in a notification
Compression	oxipng (PNG), jpegoptim (JPEG), cwebp (WebP), ffmpeg (MP4)

Command line

Every module also works headless, so you can bind it to a shortcut in any desktop:

voltkit                       # open the control center
voltkit ocr --lang eng        # select a region → text on clipboard
voltkit pick-color            # eyedropper → HEX on clipboard
voltkit color '#3584e4'       # HEX / RGB / HSL + contrast vs white/black
voltkit compress *.png --quality 75
voltkit expand 'Hi {arg:who}, {date:%A}' --arg who=Sam
voltkit qr make https://example.com  # QR code in the terminal (or --output code.png)
voltkit qr scan               # read a QR code on screen
voltkit ruler                 # measure on screen
voltkit awake 1h30m           # keep the computer awake (on / off / no argument for status)

Full documentation is in the man pages: man voltkit, man voltkit-expand, and so on.

Man pages

The pages in man/ are generated from the CLI definitions, so they always match --help. Install them next to the binary, where man finds them automatically:

mkdir -p ~/.cargo/share/man/man1 && cp man/*.1 ~/.cargo/share/man/man1/

After changing a command or its help text, regenerate them; cargo test fails until you do:

cargo run -- manpages man

Configuration

~/.config/voltkit/config.toml. Every key is optional; see data/config.example.toml.

Project layout

src/
  main.rs            CLI entry point (clap) → GUI when run with no subcommand
  app.rs             GTK4 / libadwaita control center
  daemon.rs          background service: D-Bus API, portal shortcuts, autostart
  actions.rs         hotkey actions (OCR, eyedropper) with notifications
  shortcuts.rs       accelerator conversion + GNOME keybinding fallback
  picker.rs          snippet picker popup
  snippets_ui.rs     Text Expansion page: snippet list and editor
  qr_ui.rs           QR Code page
  ruler.rs           Screen Ruler (frozen-screenshot overlay)
  awake.rs           Keep Awake (Inhibit portal, held by the daemon)
  awake_ui.rs        Keep Awake page
  system_ui.rs       Hosts & Environment page
  expander.rs        typed triggers (evdev keyboard reading, uinput virtual keyboard)
  paste.rs           paste into the focused app, restoring the clipboard
  portal.rs          XDG portal calls (screenshot, PickColor) and notifications
  config.rs          TOML config with defaults
  system.rs          Wayland/X11 helpers: clipboard, tool discovery, process runner
  modules/
    ocr.rs           region capture + Tesseract
    color.rs         parsing, HSL, WCAG luminance & contrast
    compress.rs      format detection + per-format compression pipelines
    snippets.rs      snippet template engine
    qr.rs            QR code reading and making
    hosts.rs         /etc/hosts parsing that preserves everything it doesn't edit
    envvars.rs       session environment variables (environment.d)
  manpages.rs        man page generator (clap_mangen + hand-written sections)
  screenshots.rs     renders the README screenshots (hidden `screenshots` command)
man/                 generated man pages
packaging/apt/        APT repository builder and its landing page
docs/screenshots/    README screenshots and capture.sh to regenerate them
docs/ARCHITECTURE.md design notes and roadmap

Contributing

cargo test
cargo clippy

See docs/ARCHITECTURE.md for the D-Bus API and the roadmap. The next big pieces are a Flatpak and a settings screen. Bug reports and testing on other desktops are especially welcome.

Releasing

1. Bump version in Cargo.toml, run cargo run -- manpages man, and commit.
2. Tag and push: git tag v0.2.0 && git push origin v0.2.0.

The Release workflow builds the .deb, publishes a GitHub Release with it, and rebuilds the signed APT repository on GitHub Pages. It signs with the key in the APT_SIGNING_KEY secret (fingerprint 65E8 4B8D 114C 6147 9CCA 4DDC EC0F 6B66 E480 2360). To build the repository locally: APT_KEY_ID=<fingerprint> packaging/apt/build-repo.sh target/debian site.

Author

Created by Alexis Rios-Negron.

License

MIT © Alexis Rios-Negron