nixos-config/
├── flake.nix                              # Inputs and outputs
├── flake.lock                             # Pinned input versions
├── hosts/
│   └── nixos/
│       ├── configuration.nix              # System-level config (kernel, services, users)
│       └── hardware-configuration.nix     # Auto-generated, machine-specific (not in git)
└── home/
    ├── hosts/
    │   └── nixos.nix                      # Home-manager entry point for this machine
    └── modules/                           # Reusable modules, imported by hosts/nixos.nix
        ├── niri/
        │   ├── default.nix                # Niri module (loads config.kdl + sub-modules)
        │   ├── config.kdl                 # Niri compositor config (edit this directly)
        │   ├── noctalia/
        │   │   ├── default.nix            # Noctalia shell settings
        │   │   └── wallpapers/            # Wallpaper images (add your own here)
        │   └── polkit/
        │       └── default.nix            # Polkit authentication agent (systemd service)
        ├── kitty/
        │   └── default.nix                # Kitty terminal settings
        ├── cli/
        │   └── default.nix                # Shell, git, starship, zoxide, fish
        └── applications/
            └── default.nix                # All user packages, KDE/Plasma settings

home/hosts/ and hosts/ are two different layers:

hosts/ = NixOS system config (runs as root)

home/hosts/ = home-manager user config (runs as your user)

When adding a second machine, add one file to each.

What's configured

Desktop

Niri scrollable-tiling Wayland compositor
Noctalia shell — bar, launcher, lock screen, wallpaper, idle, notifications (replaces waybar / walker / swaylock / swaybg / mako)
KDE Plasma 6 via SDDM — available as a secondary session, Breeze Dark theme
XWayland satellite for X11 app compatibility under Niri
Polkit via polkit-kde-agent-1

System

Locale: English UI (en_US.UTF-8) everywhere, timezone Asia/Ho_Chi_Minh
Vietnamese input: fcitx5 + unikey (Telex/VNI), toggle with Super+Space
Audio: Pipewire (ALSA + PulseAudio compat)
Bluetooth: enabled + Blueman applet
Power: TLP (automatic power management), UPower (battery status)
Display: DDC/CI support for external monitor brightness (ddcutil)
Fonts: JetBrainsMono Nerd Font, Noto Color Emoji, Font Awesome

Shell

zsh (default login shell) — autosuggestions, syntax highlighting, starship prompt, zoxide
fish — available as secondary shell (fish to launch)

Packages (selection)

Category	Packages
Browsers	firefox, zen-browser
AI	claude-desktop, claude-code
Terminals	kitty, ghostty, foot
Editor	vscodium
File manager	thunar + archive plugin + tumbler thumbnails
Media	mpv, imv, obs-studio, gimp, kdenlive
Office	libreoffice, zathura
Chat	telegram-desktop
CLI tools	tree, btop, htop, ripgrep, fd, fzf, eza, bat, dust, ncdu, lazygit, delta, yazi, tldr, tokei, jq, yq
System	brightnessctl, playerctl, ddcutil, grim, slurp, swappy, pavucontrol, blueman

Niri keybindings

Key	Action
`Mod+T`	Open ghostty terminal
`Mod+Space`	Noctalia launcher
`Mod+S`	Noctalia control center
`Super+Alt+L`	Lock screen
`Mod+Shift+Q`	Close window
`Mod+H/L` or `←/→`	Focus column left/right
`Mod+J/K` or `↓/↑`	Focus window down/up
`Mod+Shift+H/L` or `Shift+←/→`	Move column left/right
`Mod+Shift+J/K` or `Shift+↓/↑`	Move window down/up
`Mod+1-9`	Switch to workspace
`Mod+Shift+1-9`	Move window to workspace
`Mod+Shift+E`	Quit niri

Edit keybindings directly in home/modules/niri/config.kdl.

Reproducing on a fresh machine

1. Install NixOS

Boot the NixOS ISO and install as usual. During partitioning, set up your disks. Choose any desktop — it will be replaced.

2. Clone this repo

nix-shell -p git
git clone <repo-url> ~/nixos-config
cd ~/nixos-config

3. Copy your hardware config

hardware-configuration.nix is machine-specific and not tracked in git. Copy the one the installer generated:

cp /etc/nixos/hardware-configuration.nix ~/nixos-config/hosts/nixos/hardware-configuration.nix

4. Review `hosts/nixos/configuration.nix`

Check these fields match your machine:

networking.hostName — change if you want a different hostname
users.users.duynguyen — change username if needed (update home/hosts/nixos.nix to match)
time.timeZone — currently Asia/Ho_Chi_Minh

5. Apply the configuration

sudo nixos-rebuild switch --flake ~/nixos-config#nixos

This builds and activates the full system + home-manager config in one step.

6. Log out and back in

Required so that:

New locale settings (LC_*) take effect
Niri session appears in SDDM
Home-manager environment variables are loaded

At the SDDM login screen, select Niri from the session menu.

7. Vietnamese input (first time only)

After logging in:

Open fcitx5-configtool
Input Method tab → add Unikey
Toggle EN/VI with Super+Space

Daily usage

Task	Command
Apply changes	`sudo nixos-rebuild switch --flake ~/nixos-config#nixos`
Update all flake inputs	`nix flake update`
Update one input	`nix flake update noctalia`
Roll back last switch	`sudo nixos-rebuild switch --rollback`
Search packages	`nix search nixpkgs <name>`
Check what changed	`git diff`

How to modify things

Add a package

Open home/modules/applications/default.nix and add to home.packages.

Change niri settings

Edit home/modules/niri/config.kdl directly. Niri reloads the config automatically when the file changes after a rebuild.

Change noctalia bar / theme / idle

Edit home/modules/niri/noctalia/default.nix.

Add a wallpaper

Drop an image into home/modules/niri/noctalia/wallpapers/ and commit it.

Add a new machine

hosts/<name>/configuration.nix + hardware-configuration.nix
home/hosts/<name>.nix — import the modules you want
Add a new nixosConfigurations.<name> entry in flake.nix

README.md

nixos-config

Structure