Adding Modules

How module auto-import works in nix-wire.

---

Directory layout

Modules live under modules/ with four subdirectories:

modules/
├── nixos/     # → nixosModules
├── darwin/    # → darwinModules
├── home/      # → homeModules
└── flake/     # → flakeModules

Each subdirectory is scanned independently, and every .nix file or directory with default.nix becomes a module in the corresponding flake attribute.

File styles

Same convention as hosts - flat file or directory:

modules/nixos/
├── shell.nix               # → nixosModules.shell
├── fonts/
│   └── default.nix          # → nixosModules.fonts
└── networking/
    └── default.nix          # → nixosModules.networking

What wireModules does

wireModules = { dir }:
  wireGeneric {
    inherit dir;
    buildFn = path: name: path;
  };

The simplest specialization - buildFn just returns the path. The result is an attrset mapping names to paths:

nixosModules = {
  shell = ./modules/nixos/shell.nix;
  fonts = ./modules/nixos/fonts;
  networking = ./modules/nixos/networking;
}

Using modules in hosts

Modules are available via flake (alias for inputs.self) in special args:

# hosts/nixos/myhost/default.nix
{ flake, ... }:
{
  imports = [
    flake.nixosModules.shell
    flake.nixosModules.fonts
  ];
}

# hosts/darwin/macbook/users/carol/default.nix
{ flake, ... }:
{
  imports = [
    flake.homeModules.shell
    flake.homeModules.editor
  ];
}

Module types

NixOS modules (modules/nixos/)

Standard NixOS modules. Receive { pkgs, lib, config, options, ... } plus the special args { inputs, flake }.

# modules/nixos/shell.nix
{ pkgs, ... }:
{
  environment.systemPackages = with pkgs; [ zsh fzf starship ];

  programs.zsh.enable = true;
}

Darwin modules (modules/darwin/)

nix-darwin modules. Same interface as NixOS modules but for macOS.

# modules/darwin/brew.nix
{ ... }:
{
  homebrew = {
    enable = true;
    brews = [ "ripgrep" ];
  };
}

Home Manager modules (modules/home/)

Home Manager modules for per-user configs. Receive { pkgs, config, ... } plus special args.

# modules/home/shell.nix
{ pkgs, ... }:
{
  programs.zsh.enable = true;
  programs.starship.enable = true;

  home.packages = with pkgs; [ fzf bat eza ];
}

Flake modules (modules/flake/)

flake-parts modules. These are imported into the flake-parts mkFlake call. Use for flake-level configuration (pre-commit, treefmt, CI, etc.).

# modules/flake/treefmt.nix
{ ... }:
{
  perSystem = { pkgs, ... }: {
    treefmt = {
      enable = true;
      programs.nixpkgs-fmt.enable = true;
    };
  };
}

Flake modules and imports

Flake modules from modules/flake/ are available as flakeModules.<name> but are not automatically imported. To use them, pass them via the imports parameter:

outputs = inputs: inputs.nix-wire.mkFlake {
  inherit inputs;
  imports = [ inputs.self.flakeModules.treefmt ];
};

Or import directly:

outputs = inputs: inputs.nix-wire.mkFlake {
  inherit inputs;
  imports = [ ./modules/flake/treefmt.nix ];
};

---

Custom module directory

There's no parameter to change the modules/ directory name - it's hardcoded as ${prefix}/modules/<type>/. But you can change prefix:

outputs = inputs: inputs.nix-wire.mkFlake {
  inherit inputs;
  prefix = ./config;  # Now looks for config/modules/nixos/, etc.
};