{
  description = "Zentralwerk network";

  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs";
    zentralwerk-network-key.url = "git+https://gitea.c3d2.de/zentralwerk/network.git?dir=nix/key&ref=nix";
  };

  outputs = inputs@{ self, nixpkgs, zentralwerk-network-key }:
    let
      system = "x86_64-linux";
      systems = [ system ];
      forAllSystems = nixpkgs.lib.genAttrs systems;

      nixosConfig = name:
        self.lib.nixosSystem {
          inherit system;
          modules = [ self.nixosModule ];
          specialArgs.hostName = name;
          specialArgs.lib = self.lib;
          specialArgs.self = self;
          specialArgs.inputs = inputs;
        };
    in {
      lib = nixpkgs.lib.extend (final: prev:
        import ./nix/lib {
          inherit self;
          inherit (zentralwerk-network-key.lib) gpgKey;
          pkgs = nixpkgs.legacyPackages.x86_64-linux;
        });

      packages = forAllSystems (system:
        import ./nix/pkgs { inherit self nixpkgs system; }
      );

      nixosModule = { ... }: {
        imports = [ ./nix/nixos-module ];
      };

      nixosConfigurations =
        builtins.mapAttrs (hostName: _: nixosConfig hostName) (
          nixpkgs.lib.filterAttrs (_: { role, ... }:
            builtins.elem role [ "server" "container" ]
          ) self.lib.config.site.hosts
        );

      checks = self.packages;
    };
}