{
  description = "nixos and macos configurations";

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

    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";

    nixos-hardware.url = "github:NixOS/nixos-hardware/master";

    neovim-nightly-overlay.url = "github:nix-community/neovim-nightly-overlay";

    darwin = {
      url = "github:lnl7/nix-darwin";
      inputs.nixpkgs.follows = "nixpkgs";
    };
  };

  outputs = {
    self,
    darwin,
    home-manager,
    nixpkgs,
    nixos-hardware,
    ...
  } @ inputs: {
    nixosConfigurations = let
      defaultModules = [
        home-manager.nixosModules.home-manager
        ./common/fonts.nix
        ./packages/common.nix

        ({
          config,
          lib,
          lib',
          ...
        }: {
          config = {
            _module.args = {
              lib' = lib // import ./lib {inherit config lib;};
            };

            nix = {
              settings = {
                auto-optimise-store = true;
                sandbox = false;
                substituters = ["https://davegallant.cachix.org"];
                trusted-users = ["root" "dave"];
                trusted-public-keys = [
                  "davegallant.cachix.org-1:SsUMqL4+tF2R3/G6X903E9laLlY1rES2QKFfePegF08="
                ];
              };
              registry = {nixpkgs.flake = nixpkgs;};
            };

            nixpkgs.overlays = [
              (import ./modules/overlays)
              inputs.neovim-nightly-overlay.overlay
            ];

            home-manager = {
              useGlobalPkgs = true;
              useUserPackages = true;
              users.dave.imports = [./home/default.nix];
            };
          };
        })
      ];
      desktopLinuxModules = [
        ./common/desktop.nix
        ./common/linux.nix
        ./common/networking.nix
        ./common/printing.nix
        ./packages/desktop.nix
        ./services/keyleds/default.nix
        ./services/netdata/default.nix
      ];
    in {
      hephaestus = nixpkgs.lib.nixosSystem {
        system = "x86_64-linux";
        modules =
          [
            ./machines/hephaestus/configuration.nix
            ./machines/hephaestus/hardware.nix
          ]
          ++ defaultModules
          ++ desktopLinuxModules;
      };
      gallantis = nixpkgs.lib.nixosSystem {
        system = "x86_64-linux";
        modules =
          [
            ./machines/gallantis/configuration.nix
          ]
          ++ defaultModules;
      };
    };

    darwinConfigurations = {
      zelus = darwin.lib.darwinSystem {
        system = "aarch64-darwin";

        modules = [
          home-manager.darwinModules.home-manager
          ./common/darwin.nix
          ./packages/common.nix

          ./machines/zelus/configuration.nix

          ./modules/darwin/default.nix

          ({config, ...}: {
            config = {
              nixpkgs.overlays = [
                inputs.neovim-nightly-overlay.overlay
                (import ./modules/overlays)
              ];
              home-manager = {
                useGlobalPkgs = true;
                useUserPackages = true;
                users."dave.gallant".imports = [./home/default.nix];
              };
            };
          })
        ];
      };
    };
  };
}