{
  description = "nixos and macos configurations";

  inputs = {
    nixpkgs-unstable.url = "github:NixOS/nixpkgs/nixos-unstable";
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-25.11";
    darwin = {
      url = "github:lnl7/nix-darwin/nix-darwin-25.11";
      inputs.nixpkgs.follows = "nixpkgs";
    };
    home-manager.url = "github:nix-community/home-manager/release-25.11";
    nixvim = {
      url = "github:nix-community/nixvim/nixos-25.11";
      inputs.nixpkgs.follows = "nixpkgs";
    };
    vpngate.url = "github:davegallant/vpngate";
    weathr.url = "github:Veirt/weathr";
  };

  outputs =
    {
      darwin,
      home-manager,
      nixpkgs,
      nixpkgs-unstable,
      vpngate,
      weathr,
      ...
    }@inputs:
    let
      mkUnstable =
        system:
        import nixpkgs-unstable {
          inherit system;
          config.allowUnfree = true;
        };

      mkSharedModules =
        {
          username,
          system,
          hmModule,
          extraModules ? [ ],
        }:
        let
          unstable = mkUnstable system;
        in
        [
          ./packages.nix
          hmModule
          (
            { ... }:
            {
              config = {
                nixpkgs.config.allowUnfree = true;
                nixpkgs.overlays = [ (import ./overlays) ];
                home-manager = {
                  useGlobalPkgs = true;
                  useUserPackages = true;
                  users.${username}.imports = [
                    ./home.nix
                    inputs.nixvim.homeModules.nixvim
                    weathr.homeModules.weathr
                  ];
                  extraSpecialArgs = { inherit unstable; };
                };
              };
            }
          )
        ]
        ++ extraModules;
    in
    {
      nixosConfigurations =
        let
          system = "x86_64-linux";
          unstable = mkUnstable system;
        in
        {
          hephaestus = nixpkgs.lib.nixosSystem {
            specialArgs = {
              inherit
                unstable
                vpngate
                inputs
                ;
            };
            modules = mkSharedModules {
              username = "dave";
              inherit system;
              hmModule = home-manager.nixosModules.home-manager;
              extraModules = [
                ./hosts/hephaestus.nix
                (
                  { ... }:
                  {
                    config.nix = {
                      settings = {
                        auto-optimise-store = true;
                        substituters = [ "https://davegallant.cachix.org" ];
                        trusted-users = [ "root" ];
                        trusted-public-keys = [
                          "davegallant.cachix.org-1:SsUMqL4+tF2R3/G6X903E9laLlY1rES2QKFfePegF08="
                        ];
                      };
                      registry = {
                        nixpkgs.flake = nixpkgs;
                      };
                      gc = {
                        automatic = true;
                        dates = "daily";
                        options = "--delete-older-than 14d";
                      };
                    };
                  }
                )
              ];
            };
          };
        };

      darwinConfigurations =
        let
          system = "aarch64-darwin";
          unstable = mkUnstable system;
        in
        {
          zelus = darwin.lib.darwinSystem {
            inherit system;
            specialArgs = {
              inherit unstable inputs;
            };
            modules = mkSharedModules {
              username = "dave.gallant";
              inherit system;
              hmModule = home-manager.darwinModules.home-manager;
              extraModules = [
                ./hosts/zelus.nix
              ];
            };
          };
        };
    };
}