nix-module

name	nix-module
description	Conventions for writing NixOS and Home Manager modules in the NyxOS Dendritic flake-parts repository. Load before touching any .nix file.
compatibility	opencode

File layout

• Topic modules: modules/<camelCase>.nix
• Host configs: modules/hosts/<camelCase>.nix
• flake.nix is auto-generated — never edit. Add inputs only in flake-file.inputs blocks.
• Module file signature: { inputs, ... }: (use { ... }: when no inputs needed)

Declaring flake inputs

flake-file.inputs = {
  some-input.url = "github:owner/repo";
  some-input.inputs.nixpkgs.follows = "nixpkgs";  # always required
};

After adding/changing inputs, run regenerate (nix run ~/NyxOS#write-flake).

Module registration

• System modules: flake.modules.nixos.<kebab-case>
• Home Manager modules: flake.modules.homeManager.<kebab-case>
• Each definition needs a preceding comment:

  # System Module <name>: <description>
  # Home Module <name>: <description>
  

• Description must exactly match the README.md entry. Update both together.

Hosts

Declared in modules/hosts/<camelCase>.nix as flake.nixosConfigurations.<PascalCase>.

Host	Arch	Notes
EliasPC	x86_64-linux	Intel + AMD GPU, desktop, distributed-builder
EliasLaptop	x86_64-linux	Intel + NVIDIA GPU, isMobile = true
FredPC	x86_64-linux	KDE, German locale
NixPi	aarch64-linux	Raspberry Pi, no desktop

nixpkgs channels

• pkgs → nixos-unstable (default)
• pkgs-stable → nixos-25.11 (via specialArgs; use only for packages that break on unstable, e.g. libreoffice, kdenlive)

Code style

# let bindings before attrset body
let myPkg = pkgs.foo.override { bar = true; }; in
{
  environment.systemPackages = with pkgs; [ pkg1 pkg2 ];
  boot.binfmt.emulatedSystems = lib.mkIf (system == "x86_64-linux") [ "aarch64-linux" ];
  some.option = lib.mkDefault "value";
  other.option = lib.mkForce "override";
}

• Cross-module data → specialArgs / extraSpecialArgs, not options
• Paths → config.home.homeDirectory, never /home/elias or ~
• Arch-specific → lib.mkIf (system == "x86_64-linux") { ... }
• Host imports: imports = with inputs.self.modules.nixos; [ foo bar ];

Naming

Item	Convention
Module files	camelCase.nix
NixOS / HM module names	kebab-case
nixosConfigurations keys	PascalCase
let variables	camelCase

Validation

nixpkgs-fmt <file>.nix   # format single file
nixpkgs-fmt .            # format all

Do not build or run flake check! Building is reserved for the developer, except when explicitly requested.

Use only the LSP for checking.

MCP tools

• mcp-nixos — NixOS/HM option lookup, package search, nixpkgs attributes. Prefer this for anything Nix-ecosystem.
• context7 — upstream library docs, non-NixOS API references.