Babbage

An opinionated Debian 13 desktop, built with Nix
XFCE + i3 tiling · flat menu bar · Ghostty · notifications that slide into the bar

_{The face of the project is Charles Babbage, after an 1860 photograph (public domain), printed as a halftone. Identity: docs/identity/IDENTITY.md.}

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An opinionated Debian 13 setup: XFCE running i3 tiling, one flat menu bar, Ghostty, and notifications that slide into the bar. One command takes a fresh Debian install there, built with a Nix Home Manager flake.

_{3840×2160, taken in a Debian 13 VM set up by bootstrap.sh al3rez-vm: two Ghostty windows tiled by i3 (the focused one bright, the other dimmed), every window with the ring edge (picom's GLX backend, as on the NVIDIA profile; the Mesa profile's xrender draws no edges), a notification in the middle of the bar. Below, the two top halves at 1:1 (no scaling).}

Left: workspace + pinned apps	Right: notification in the bar, status icons, clock

The second monitor (ASUS MB16FC, 1920×1200 at 150%) gets its own bar: only its own workspaces (4–6), the same pinned apps, volume, search, control centre and clock; the tray stays on the main bar. Taken on this machine with T3 Code open (its project list and thread blurred):

Window edges come in three styles (edge in modules/compositor.nix), shown here 3× where the focused window (left) meets an unfocused one:

ring (default): 1pt dark outline + light rim	hairline: 1pt light rim, brightest on top	gloss: a glint lit from the top-left

Installed and pinned by default, each with a matching rounded icon (Telegram and Hex live in the tray):

Ghostty	Grok Bot	ChatGPT	T3 Code	Slack	WhatsApp
DeepSeek Harness	Chrome	Steam	Telegram	Hex

Notifications are one line in the middle of the bar: no card, no background. picom slides them down in and back up out (recorded in the VM at 60 fps, real speed, then 4× slower):

git clone https://github.com/al3rez/babbage ~/.config/home-manager
~/.config/home-manager/bootstrap.sh              # NVIDIA machine (LG 4K + ASUS layout)
~/.config/home-manager/bootstrap.sh al3rez-vm    # anything else (Mesa)

After the first run, apply changes with:

home-manager switch --flake ~/.config/home-manager#al3rez

What it sets up

Area	Where
i3 instead of xfwm4 in the XFCE session, 12px gaps, no window borders (picom dims unfocused windows instead)	modules/session.nix, modules/i3.nix, files/i3/config
Top bar: i3 workspace numbers, Ghostty + Grok Bot + ChatGPT + T3 Code + Slack + WhatsApp + DeepSeek Harness + Chrome + Steam left, tray / volume / search / control centre / clock right, ends aligned to i3 gaps. Two looks, barStyle in modules/panel.nix: black (flat solid black, the default) or clear (transparent over the wallpaper). NVIDIA profile: one bar per monitor, each listing only its own workspaces (tray on the LG only)	modules/panel.nix, files/gtk-3.0/gtk.css
Workspaces belong to a monitor: 1–3 the LG, 4–6 the ASUS (Super+N jumps to that monitor; Super+Ctrl+←/→ sends a window across). Each bar always shows its own three numbers, read from i3's config by i3-ws-bar (focused bright, other monitor's dimmer, rest dim, empty faint, urgent red; click to switch)	files/i3/config, modules/i3.nix, files/bin/i3-ws-bar
Pinned apps behave like the macOS Dock: a click focuses the app's window wherever it is (any workspace or monitor) and starts it if it has none; a double-click opens a new window. A notification from a pinned app puts a small white dot under its icon on every bar until you focus it	files/bin/focus-or-launch, modules/panel.nix, files/bin/menubar-popovers, modules/notifications.nix
Grok Bot (Cursor's apt repo), ChatGPT with Codex (OpenAI's official .deb, which adds its signed apt repo for updates) and T3 Code nightly (GitHub, digest-checked), installed in the background; pinned on the bar with matching macOS squircle icons (files/bin/make-app-icon fits any app's artwork into Grok Bot's squircle)	files/bin/install-desktop-apps, files/icons/hicolor/, modules/panel.nix
Slack from nixpkgs (GPU-wrapped like Ghostty/Telegram), pinned with the same squircle icon (slack-mac, made with make-app-icon); its colour tray icon is hidden. The switch rebuilds a stale ~/.local/share/icons/hicolor icon cache so newly added icons show up	home.nix, modules/packages.nix, modules/panel.nix, modules/theme.nix, files/icons/hicolor/
WhatsApp as a web app, the way Omarchy does it: WhatsApp Web in a Chromium (nixpkgs) app window with its own window class, pinned with the macOS WhatsApp icon (Mac App Store artwork through make-app-icon --square)	modules/panel.nix, home.nix, files/icons/hicolor/
DeepSeek Harness (deepseek-ai/deepseek-harness, developer preview, MIT), pinned after WhatsApp with DeepSeek's App Store icon (make-app-icon --square). dsh runs the pinned npm release 0.2.2-rc.1 through npx on nodejs.org's official Node 24.21.0 (hash-pinned, used unpatched: the harness's native loader rejects nixpkgs' Node build). The pin starts the dsh-web user service (dsh web on 127.0.0.1:3080) if needed, reads the per-start access-token URL it printed, and opens it in a Chromium app window with its own profile and DeepSeek window class. Models come from an Alibaba Cloud Model Studio Token Plan: provider bailian-tpp (Alibaba's documented setup, DeepSeek V4.1 Flash as the default for new sessions, like omp; the first-run "Get started" sign-in popup is off via ui-settings-models.credentialOnboarding: false) in ~/.dsh/profiles/web/cordis.patch.yml, which the Settings page also edits so it isn't managed here; the key is BAILIAN_API_KEY in ~/.config/dsh/bailian.env (0600, not in the repo; the same Token Plan key omp uses as alibaba-token-plan), loaded by the service. The main window tiles (i3 rule; Chromium app windows have the pop-up role); DeepSeek's account sign-in popup still floats. It runs model-generated commands with your user's access, so keep it to project directories	files/pkgs/dsh.nix, modules/deepseek-harness.nix, modules/panel.nix, files/icons/hicolor/
Hex local voice dictation: hold Alt+Space, speak, release, and the text is pasted where the cursor is (Ctrl+Alt+V pastes the last one again); transcription runs on this machine. From Hex's official flake (github:anomalyco/hex, built from source, nixpkgs follows ours) with its Home Manager module, GPU-wrapped for Vulkan like the other apps. XFCE never starts graphical-session.target, so i3 starts hex.service; hex-model downloads the speech model once. Its tray icon is a white glyph of Hex's hexagon mark drawn by menubar-popovers (Hex itself sends a fixed colour bitmap). Update with nix flake update hex; hex opens its window	modules/hex.nix, flake.nix, home.nix, files/i3/config
Google Chrome from Google's .deb (its apt repo keeps it updated), pinned before Steam; Firefox is no longer installed by bootstrap or pinned. Chrome's icon uses app.icns from Google's stable macOS download, version 156.0.8078.80, fitted with the same files/bin/make-app-icon helper as the other apps and installed as a WhiteSur-Mac override. Chrome handles web links and is XFCE's preferred browser and Debian's x-www-browser. The user-local Slack entry handles slack:// links from host browsers	modules/packages.nix, files/bin/install-desktop-apps, modules/panel.nix, files/icons/WhiteSur-Mac/scalable/google-chrome.png
Steam installed per-user from Flathub on activation, with Flatpak supplied by Nix and its session D-Bus services registered for Debian. Includes matching 64/32-bit NVIDIA runtimes without changing the host driver. Pinned after Chrome on both bars with official artwork from the installed Steam app, processed by make-app-icon, and click-to-focus behavior; also available as steam. Steam updates its client; update the Flatpak app/runtimes with flatpak update --user after switching Home Manager	modules/packages.nix, modules/panel.nix, files/icons/WhiteSur-Mac/scalable/steam.png
Minimal Raycast-style launcher on Super+Space: rofi with a frosted, rounded theme, a search field and one flat list of apps (the ones you open most first, then A–Z). Fuzzy search; Enter opens, Esc closes	files/bin/launcher, files/rofi/launcher.rasi, modules/i3.nix, files/picom/picom.conf
Clipboard History on Super+Shift+V, like Raycast's: a recorder (clipboard-history user service) keeps text, links, colors and images (1000 entries / 90 days, ~/.local/share/clipboard-history, mode 0700; password-manager copies skipped). The window is the launcher's: it reads launcher.rasi for its size, colors and spacing, so both always match, with a preview of the selected entry on the right (the image, the text or the color). Enter pastes into the app you were in (Ctrl+Shift+V in terminals), Ctrl+Enter only copies, Shift+Delete removes the entry	files/bin/clipboard-history, modules/i3.nix, files/i3/config, files/picom/picom.conf
Region screenshot on Ctrl+Shift+4 (like macOS ⌘⇧4): drag a region; it's saved to ~/Pictures/Screenshots/Screenshot <date> at <time>.png and copied to the clipboard. Esc cancels	modules/i3.nix, files/i3/config
Light by day, dark by night: from 07:00 Adwaita and GNOME's prefer-light colour scheme, from 19:00 Adwaita-dark and prefer-dark (GTK3 apps take the theme; GTK4, Chrome, Electron and Ghostty follow the colour scheme). A user timer switches at those times and once at login; change them at the top of modules/appearance.nix. 144 DPI, Inter, WhiteSur-Mac icons, dark cursor (mate-black, 32 px, the same in every toolkit)	modules/appearance.nix, modules/xfce.nix, modules/session.nix, modules/theme.nix
picom: square window corners by default (corners in modules/compositor.nix: square, or rounded for 15px corners, 10pt at 1.5x) and a window edge style that follows either shape on app windows and Clipboard History, chosen by edge in modules/compositor.nix (GLX only): gloss, a glass glint lit from the top-left (gloss.frag); ring, the macOS background-window edge, a 1pt dark outline plus a 1pt light inner rim (edge-ring.frag); hairline, the macOS key-window edge, a 1pt light rim brightest on top, darkening slightly on light windows (edge-hairline.frag). Every unfocused window dimmed, transparent bar, notification slide; frosted glass (blur) only behind the launcher, Clipboard History and menus. Menus (tray right-click, panel, apps) styled like macOS light menus: frosted, rounded, dark text, blue highlight. Tray shows only white glyphs: Electron apps' colour tray icons (ChatGPT, Slack) are hidden	modules/compositor.nix, files/picom/picom.conf, files/picom/*.frag, files/gtk-3.0/gtk.css, modules/panel.nix
dunst: one line in the centre of the bar, text only (no app icon), slides in/out	modules/notifications.nix, files/dunst/dunstrc
Ghostty: Berkeley Mono (TX-02), size 10, terminal padding, Superlogical tabs, terminfo, omp's light theme by day and its dark theme by night (themes/omp-light, themes/omp-dark), and a curved-screen shader (shaders/curve.glsl: a slight CRT-style bulge and soft corner darkening, text stays sharp; remove custom-shader to turn it off). Panel icon: original rounded silver-frame macOS artwork from Ghostty's repository, preserving the frame and matching Grok's visible bounds on a 512×512 canvas. Ghostty, Grok, and Steam have the same 26px visible height at the panel's 30px icon size (alpha ≥128); no extra squircle mask on Ghostty	modules/ghostty.nix, files/ghostty/, files/icons/WhiteSur-Mac/scalable/com.mitchellh.ghostty.png
Telegram Desktop with tray icon sized to match	modules/packages.nix, files/icons/WhiteSur-Mac/
Wallpaper (wallhaven gp7mq3, hash-pinned)	home.nix
Bash prompt	modules/shell.nix, files/bash/prompt.sh
Tailscale (official apt repo, daemon enabled, user is operator, Tailscale SSH on; run tailscale up once per machine). In the tray as a flat white dot mark like the other tray icons (faint when disconnected); clicking it opens a macOS-style popover (Wi-Fi, Telegram and Bluetooth open the same popover with their own menus): on/off switch, this device and its IP, every device with its IP (click copies), offline devices, exit node, admin console. The popovers also draw the bar's Wi-Fi, Bluetooth, Telegram and Tailscale icons, so they run as the menubar-popovers user service, which restarts itself if it ever exits. No microphone indicator: the volume item's own (red, on whenever anything records) is hidden. Tray order is pinned in known-items. Clipman's tray icon is Lucide's clipboard (ISC licence) in white, with the other tray icons' ~2.4px line weight, 20px tall (2px taller than the 18px glyphs, so the narrow board doesn't read small) (clipman.svg)	bootstrap.sh, files/apt/tailscale.gpg, files/bin/menubar-popovers, files/icons/tailscale/, modules/panel.nix
Power: monitors off after 10 idle minutes via XFCE DPMS; display-blanking disables the separate X screensaver timer. System never sleeps (caffeine user service holds a logind sleep block)	modules/power.nix
LG 4K@240 + ASUS MB16FC at native 1920x1200@75, dual-only MetaModes in /etc/X11/xorg.conf.d/20-nvidia-desk.conf, soft DPMS (HardDPMS false), and both outputs pinned as connected with their own EDIDs (ConnectedMonitor + CustomEDID, files in files/xorg/edid/ with the monitors' serial numbers zeroed, installed to /etc/X11/edid/), so switching a monitor off with its power button no longer removes it from X: the layout, workspaces and menu bars stay put. XFCE's default profile matches this layout; automatic profile selection and hotplug dialogs are disabled. apply-desk-layout uses cached xrandr --current and does nothing when geometry/primary are already correct. monitor-layout-guard handles RandR changes and checks cached X DPMS/idle state every 5 seconds for user return without a RandR event. When the LG wakes from DPMS off it sometimes keeps dropping and retrying its DisplayPort link and stays black while X thinks it's on; the guard spots that in the X log (one monitor reconnecting 3+ times within 90 seconds, a good wake reconnects once), waits 25 seconds for the retries to stop, and gives that monitor one fresh mode set (another refresh rate, then back), which brings the picture back. Missing outputs retry with 10–300 second backoff; no modeset while asleep, idle, or an output is missing. Failed commands remain visible and a 30-second timeout kills the recovery process group. On the same 5-second tick it puts a menu bar back on its own monitor if i3 docked it on the other one (after a panel restart), going by the bar's own reserved-space property. Every monitor that is on must have a bar docked by i3: if one hasn't for 8 seconds while you're active (i3 dropped the bars after the monitors came back, or the panel is down or hung), it restarts xfce4-panel, killing it if it won't quit, at most once a minute. This also runs while the other monitor is off; a bar hidden under a fullscreen window counts as present and is left alone. It never probes the driver. Correct cached geometry cannot prove a panel physically woke up. Logs: journalctl --user -u monitor-layout-guard	files/xorg/20-nvidia-desk.conf, files/xorg/edid/, files/bin/apply-desk-layout, files/bin/monitor-layout-guard, modules/monitors.nix
RGB lighting off: both DDR5 sticks (ENE) and the ASRock B850M board's lighting controller (RGB header and the three addressable headers), set to Off by OpenRGB on every login (rgb-off user service), since RAM lighting resets when power is cut. Needs OpenRGB's udev rules in /etc/udev/rules.d (bootstrap.sh installs them). The Logitech G304 is left alone	modules/rgb.nix, bootstrap.sh

Moving this machine onto the flake

The live desktop was set up by hand first; a few of those pieces would shadow or duplicate the Nix ones, so remove them before the first switch:

rm -f ~/.local/bin/ghostty ~/.local/bin/telegram                  # AppImage / tarball launchers
rm -f ~/.local/bin/i3-ws-bar                                      # now a Nix store script
rm -f ~/.local/share/applications/com.mitchellh.ghostty.desktop
rm -f ~/.config/autostart/picom.desktop                           # i3 starts picom now
rm -rf ~/.local/share/fonts/NerdFontsSymbolsOnly ~/.local/share/fonts/Inter  # Nix ships both
./bootstrap.sh

Home Manager moves any other existing file it takes over to *.backup.

Not in the repo: Berkeley Mono is a paid font, so font-family = TX-02 only works once its files are in ~/.local/share/fonts/BerkeleyMono-TX-02/; without them Ghostty uses its default font.

The genmon slot files (~/.config/xfce4/panel/genmon-*.rc) are copied, not linked: the panel writes plugin settings back on exit, so the switch stops the panel, replaces them, and starts it again. Editing them by hand needs the same order (xfce4-panel -q, edit, xfce4-panel &).

Tested

Fresh Debian 13 (trixie) VM, task-xfce-desktop, then ./bootstrap.sh al3rez-vm: i3 session, transparent bar, wallpaper, Ghostty tabs + prompt, Telegram tray icon, centred notification, picom all come up on first login.

If the screen ever stays black

Nothing should cause this any more, but to recover without powering off:

• Ctrl+Alt+F3, log in, then sudo systemctl restart gdm (restarts the graphical session)
• or from another machine: ssh al3rez over Tailscale, same command
• if a new X config is the cause: sudo rm /etc/X11/xorg.conf.d/20-nvidia-desk.conf first