Flakes & Nix Interop

nixmac generates and manages a Nix flake for your nix-darwin configuration. If you're already using flakes, nix-darwin, or home-manager, nixmac works with your existing setup.

nixmac's default flake

When nixmac bootstraps a new configuration from the app, it uses the bundled nix-darwin-determinate template. It is a regular nix-darwin flake with Determinate Nix-friendly defaults, including nix.enable = false, system.primaryUser, and Homebrew management enabled:

{
  description = "My Mac configuration";

  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
    nix-darwin.url = "github:nix-darwin/nix-darwin/master";
    nix-darwin.inputs.nixpkgs.follows = "nixpkgs";
  };

  outputs = inputs@{ self, nix-darwin, nixpkgs, ... }: {
    darwinConfigurations."my-hostname" = nix-darwin.lib.darwinSystem {
      modules = [
        ./modules/darwin/packages.nix
        ./modules/darwin/defaults.nix
        ./modules/darwin/homebrew.nix
        # ... other modules
      ];
    };
  };
}

This is standard nix-darwin configuration — nothing proprietary. You can rebuild it independent of nixmac using darwin-rebuild switch --flake . (or sudo -i nix run nix-darwin/master#darwin-rebuild -- switch --flake . on Determinate Nix installs).

Existing nix-darwin configurations

If you already have a nix-darwin setup, point nixmac at it:

1. Open nixmac settings
2. Set the config directory to your existing flake location
3. nixmac will read and work with your existing configuration

nixmac's AI agent understands standard nix-darwin module structure. It will edit your existing files rather than replacing them.

home-manager

nixmac's templates support home-manager as an optional input. To enable it, uncomment the home-manager lines in your flake.nix and add home-manager.darwinModules.home-manager to your modules list:

inputs = {
  # ...
  home-manager = {
    url = "github:nix-community/home-manager";
    inputs.nixpkgs.follows = "nixpkgs";
  };
};

The AI agent knows about home-manager and can configure user-level programs (git, zsh, neovim, etc.) through home.packages and program-specific modules.

Other templates in the repo

The repository also includes a nixos-unified template that uses flake-parts for more advanced manual setups:

{
  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
    nix-darwin.url = "github:LnL7/nix-darwin";
    home-manager.url = "github:nix-community/home-manager";
    flake-parts.url = "github:hercules-ci/flake-parts";
    nixos-unified.url = "github:srid/nixos-unified";
  };

  outputs = inputs:
    inputs.nixos-unified.lib.mkFlake {
      inherit inputs;
      root = ./.;
    };
}

This is useful if you manage both macOS and NixOS machines from a single flake. The app's default bootstrap flow currently creates the nix-darwin-determinate template; use other templates manually.

Pinning and updates

Your flake.lock pins all input versions. nixmac respects this — it will not silently update your dependencies.

To update inputs, run:

cd ~/.darwin
nix flake update

Or update a specific input:

nix flake update nixpkgs

Relationship to darwin-rebuild

Under the hood, nix-darwin uses darwin-rebuild switch to activate configurations. nixmac separates activation from commit:

1. You (or the AI agent) edits .nix files in ~/.darwin/
2. You click Build & Test in the nixmac UI
3. nixmac builds the configuration, then activates the result with administrator approval
4. You commit the active changes to record them in git

This is the same underlying nix-darwin activation model as using darwin-rebuild manually — nixmac automates the "edit files" step with AI and provides a GUI around activation, undo, and git history.

Next steps