{
  description = "personal NixOS configurations";

  inputs = {
    # Nixpkgs, NixOS's official repo
    nixpkgs.url = "github:nixos/nixpkgs/release-21.11";
  };

  # Output config, or config for NixOS system
  outputs = { self, nixpkgs, ... }@inputs: {
    nixosConfigurations = {
      # desktop
      carmel = nixpkgs.lib.nixosSystem {
        system = "x86_64-linux";
        modules = [
          ./hosts/carmel/configuration.nix
        ];
      };
    };
  };
}