Noctalia

Haxorus uses Noctalia for its Wayland shell. It replaces Waybar, rofi, cliphist, mako, SwayOSD, hyprpaper, hypridle, hyprlock, the power menu, and the old screenshot scripts. Umbriel provides the compositor.

Session

Choose Umbriel in GDM. Umbriel starts umbriel-session.target, which starts Noctalia as a systemd user service. Noctalia then provides the shell surfaces and desktop services for that session.

Noctalia is configured in conf/modules/de/noct.nix. The module imports its NixOS and Home Manager modules. The ThinkPad configuration imports noct.nix.

The first rebuild must accept the Noctalia binary cache configuration:

sudo nixos-rebuild switch --accept-flake-config \
  --flake "$NIXOS_CONFIG#nix-haxorus"

That generation adds the cache to the system Nix settings, so later rebuilds can use the normal rebuild alias.

Configuration ownership

Home Manager generates the read-only Noctalia configuration at ~/.config/noctalia/config.toml from programs.noctalia.settings in noct.nix.

Noctalia stores changes made through Settings and the desktop widget editor in ~/.local/state/noctalia/settings.toml. This writable file loads after the Home Manager file, so a saved GUI value overrides the corresponding value in noct.nix.

Delete the relevant key from settings.toml, or delete the whole file while Noctalia is stopped, to return that setting to Home Manager. Use Settings → Export Config → Merged User Config to inspect or promote GUI changes. Move wanted values into noct.nix, rebuild, and remove their GUI overrides. Do not edit the Home Manager symlink under ~/.config.

Shell surfaces

The floating top bar has an 8 px screen margin and rounded corners. It contains:

• the launcher and per-output workspaces on the left;
• the active media player in the center;
• network, Bluetooth, volume, brightness, battery, idle inhibition, notifications, tray, clock, Control Center, and session controls on the right.

The launcher searches desktop applications and includes calculator, emoji, session, wallpaper, and window providers. Prefix a search with /calc, /emo, /session, /wall, or /win to select one provider.

Control Center provides media and stream controls, display brightness, system status, NetworkManager, Bluetooth, notification history, and UPower battery information. Weather, calendar, and screen-time tabs are hidden because those services are not configured. Session actions are also available in the separate session panel.

Noctalia is the notification daemon. Dismissing a toast keeps it in Control Center history. Do Not Disturb suppresses new toasts without stopping history.

The dock and desktop widgets are disabled.

The lock screen uses wall00.png, a dark tint, password authentication, and fingerprint authentication. Noctalia locks before suspend, including suspend caused by closing the lid.

Theme

Noctalia uses Inter and the built-in dark Eldritch palette. The custom Haxorus palette remains commented out in noct.nix so it can be restored without reconstructing its color roles.

Panels are solid and bordered rather than glassy. Application theme templates are disabled, so the palette does not rewrite GTK, Qt, terminal, or editor themes.

Idle and power

Noctalia is the only idle daemon:

Wayland idle inhibitors are honored. The bar’s caffeine control can also keep the session awake.

UPower supplies battery status and health. TLP controls CPU and laptop power policy. power-profiles-daemon is disabled to avoid conflicting with TLP, so Noctalia can show battery information but has no power-profile selector.

Screenshots and media keys

The Umbriel keymap sends screenshot and media actions to Noctalia. Screenshots open its annotation editor, save under ~/Pictures/Screenshots, and copy the result to the clipboard. Media keys control volume, microphone, brightness, and playback; Noctalia displays the corresponding OSD.

See Umbriel for the complete keymap.

Debugging

Check the service, log, IPC connection, and merged configuration:

systemctl --user status noctalia.service
journalctl --user -b -u noctalia.service
noctalia status
noctalia config validate
noctalia config export full | yq -p toml '.'

If a declared setting is ignored, inspect the winning GUI layer:

$EDITOR ~/.local/state/noctalia/settings.toml

Noctalia requires an Umbriel session for layer-shell, session lock, workspace, and output integration. See Umbriel debugging when the service runs but compositor integration fails.