Template: Minimal

The minimal template demonstrates Den’s core with zero extra dependencies beyond nixpkgs.

Initialize

mkdir my-nix && cd my-nix
nix flake init -t github:vic/den#minimal
nix flake update den

Project Structure

flake.nix
modules/
  den.nix

flake.nix

{
  outputs = inputs:
    (inputs.nixpkgs.lib.evalModules {
      modules = [ (inputs.import-tree ./modules) ];
      specialArgs = { inherit inputs; };
    }).config.flake;

  inputs = {
    nixpkgs.url = "https://channels.nixos.org/nixpkgs-unstable/nixexprs.tar.xz";
    import-tree.url = "github:vic/import-tree";
    flake-aspects.url = "github:vic/flake-aspects";
    den.url = "github:vic/den";
  };
}

Key points:

• No flake-parts — uses lib.evalModules directly
• import-tree — recursively loads all .nix files under modules/
• Results land in .config.flake (nixosConfigurations, etc.)

modules/den.nix

{ inputs, den, ... }:
{
  imports = [ inputs.den.flakeModule ];

  den.hosts.x86_64-linux.igloo.users.tux = { };

  den.aspects.igloo = {
    nixos = { pkgs, ... }: {
      environment.systemPackages = [ pkgs.hello ];
      boot.loader.grub.enable = false;  # TODO: remove for real hardware
      fileSystems."/".device = "/dev/null";
    };
  };

  den.aspects.tux = {
    includes = [ den.provides.primary-user ];
  };
}

What This Declares

1. One host named igloo on x86_64-linux with one user named tux
2. Host aspect den.aspects.igloo — provides NixOS config (a package + boot/fs stubs)
3. User aspect den.aspects.tux — includes the primary-user battery

How It Works

graph TD
  H["den.hosts.x86_64-linux.igloo"] -->|"ctx.host"| A["den.aspects.igloo"]
  H -->|"ctx.user"| U["den.aspects.tux"]
  U -->|"includes"| PU["den.provides.primary-user"]
  A -->|"resolve nixos"| NixOS["nixosConfigurations.igloo"]

1. Den reads den.hosts and creates a ctx.host { host = igloo } context
2. The host aspect igloo is activated with its NixOS config
3. For each user, a ctx.user { host, user } context is created
4. The user aspect tux includes primary-user (adds wheel/networkmanager groups)
5. Everything resolves into nixosConfigurations.igloo

Build It

nix build .#nixosConfigurations.igloo.config.system.build.toplevel

Customize

To add your own host configuration, edit den.aspects.igloo.nixos. To add user packages, add a homeManager key to den.aspects.tux (requires adding home-manager input). Or keep it simple — the minimal template works without Home-Manager.

What It Provides

Feature	Provided
NixOS host configuration	✓
User with wheel/networkmanager	✓
Home-Manager	✗
Darwin support	✗
Namespaces	✗
VM testing	✗

Next Steps

• Add more aspects in separate files under modules/
• Graduate to the Default template for Home-Manager support
• Read Core Principles to understand the context pipeline