Niri Notes

Here are some notes I jotted down while solving some minor problems with Niri, the tiling compositor for Wayland. (I am running Niri on Fedora 43 KDE Edition.) I’ve also included some tips for programs associated with Niri, including fuzzel and waybar.

Niri

Most of the solutions below involve editing Niri’s config file, ~/.config/niri/config.kdl .

Make CapsLock be Ctrl

In the input / keyboard / xkb section of the config file, uncomment the options line, or make it look like this:

  options "compose:ralt,ctrl:nocaps"

Toggle laptop screen

To add a command to toggle the laptop screen power, bound to Mod+P, first modify the off line in the section for output eDP-1 so that it has a // laptop comment as a marker:

  off // laptop

Then create the script toggle-laptop-screen:

#!/bin/sh
sed -i -E \
 -e 's#(\s+)//\s*(off\s*//\s*laptop\s*)#\1\2#;t done; s#(\s+)(off\s*//\s*laptop\s*)#\1// \2#;: done' \
 ~/.config/niri/config.kdl

Then add this line to the binds section of the config file:

    Mod+P { spawn "/home/USER/bin/toggle-laptop-screen"; }

Change the path to the actual path of the script.

Niri starts with blank white window

The problem is described here. It’s a window for xwaylandvideobridge, used in KDE. I decided not to remove it, since that might mess up some KDE programs.

As mentioned in the above link, you can find all the windows in Niri using niri msg windows. and xwaylandvideobridge is the first one in the list.

Niri color picker

From a terminal, run niri msg pick-color and then click on any point on the screen. This will print the color at the location.

Niri background image

Add this line to the config file:

spawn-at-startup "swaybg" "-m" "fill" "-i" "/usr/share/wallpapers/Path/contents/images/2560x1600.jpg"

Change the path for your favorite background image. Then restart Niri for it to take effect.

Brave Browser dialogs don’t appear

The problem is described here. You have to install and run Nautilus first; then the dialogs will appear. After the first run, you can close Nautilus.

Waybar

CPU fan widget

Waybar is the status/app bar used by default in Niri.

To add a CPU fan widget for a ThinkPad, add this custom module to the end of~/.config/waybar/config.jsonc:

    "custom/fan": {
      "exec": "sed -E -n 's/speed:\\s+//p' /proc/acpi/ibm/fan",
      "format": "{} ☢",
      "interval": 5
    }

For other laptops, you’ll have to determine which proc device gives you the fan speed. Then add this module to modules-right after the temperature widget:

    "modules-right": [
        ...
        "temperature",
        "custom/fan",
    ...
    ],

Disappearing waybar tray

At one point, perhaps after running a KDE app, the little tray box on the far right of the waybar disappeared. (The tray is useful for killing Zoom after a sesson.) This issue explains why. I verified that kded6 had taken over the status notifier using this:

busctl --user list|grep -i status

The fix was to do this:

killall kded6
killall waybar
niri msg action spawn -- waybar

I put this in a script called fixtray.

Fuzzel

Fuzzel is the app launcher used by default in Niri.

Add Sioyek to the list of apps

Sioyek is a very fast and capable PDF viewer that I like to use sometimes instead of Evince or Okular. In order to make it visible to Fuzzel, use the following steps.

Install (and rename) the sioyek appimage file to /usr/local/bin/sioyek.

Create the file ~/.local/share/applications/sioyek.desktop:

[Desktop Entry]
Name=Sioyek
Comment=Sioyek PDF viewer
Exec=/usr/local/bin/sioyek %u
GenericName=PDF viewer
Icon=sioyek
StartupWMClass=Sioyek
MimeType=application/pdf;
Terminal=false
Type=Application
Version=2.0.0
Categories=Graphics;Office;Viewer;

Create an icon directory:

mkdir -p ~/.local/share/icons/hicolor/64x64/apps

Convert the viewpdf SVG file to a PNG, rename it, and install it in the directory just created:

magick /usr/share/icons/breeze-dark/mimetypes/64/viewpdf.svg ~/.local/share/icons/hicolor/64x64/apps/sioyek.png

Alacritty

Alacritty is the terminal emulator used by default in Niri.

Font

The default font in Alacritty is “monospace regular”. To find which font is monospace, use fc-match monospace. On Fedora, this is NotoSansMono.

To display the list of all fonts use fc-list .

I prefer using DejaVuSansMono, but it isn’t installed by default in Fedora. Install it using sudo dnf install dejavu-sans-mono-fonts.noarch.

Then edit ~/.config/alacritty/alacritty.toml and add these lines:

[font]
size = 11
normal = { family = "DejaVuSansMono", style = "Regular" }

Virtualization

When run under Niri, virt-manager complains that it can’t connect to libvirtd. Running sudo systemctl status libvirtd shows the message:

Oct 16 09:35:42 dual libvirtd[4506]: authentication unavailable: no polkit agent available to authenticate action 'org.libvirt.unix.manage'
Oct 16 09:35:42 dual libvirtd[4506]: End of file while reading data: Input/output error

The Niri Important Software page has some clues about plasma-polkit-agent, but is short on details. I had to manually start the polkit as my normal user (not root!) after Niri started:

systemctl --user start plasma-polkit-agent

Then restarted libvirtd:

sudo systemctl restart libvirtd
sudo systemctl status libvirtd

The status should no longer have the error message about authentication.

I will try to find a way to start this automatically when Niri starts, per the above web page.

Ghostty

Ghostty is a very fast and capable terminal emulator that I now use instead of Alacritty. The config file is ~/.config/ghostty/config.

For some reason, Ctrl-I and Ctrl-[ aren’t mapped to Tab and Esc. Fix this using:

keybind = ctrl+i=text:\x09
keybind = ctrl+[=text:\x1b