{
  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
    nixpkgs-schule.url = "github:NixOS/nixpkgs/nixos-unstable";
    nixos-exporter = {
      url = "git+https://git.clerie.de/clerie/nixos-exporter.git";
      inputs.nixpkgs.follows = "nixpkgs";
    };
    solid-xmpp-alarm = {
      url = "git+https://git.clerie.de/clerie/solid-xmpp-alarm.git";
      inputs.nixpkgs.follows = "nixpkgs";
    };
  };
  outputs = { self, nixpkgs, nixos-exporter, solid-xmpp-alarm, ... }@inputs: let
    helper = (import ./lib/flake-helper.nix) inputs;
  in {
    nixosConfigurations = let
      inherit (helper)
        generateNixosSystem;
    in {
      aluminium = generateNixosSystem "aluminium";
      backup-4 = generateNixosSystem "backup-4";
      beryllium = generateNixosSystem "beryllium";
      carbon = generateNixosSystem "carbon";
      clerie-backup = generateNixosSystem "clerie-backup";
      dn42-il-gw1 = generateNixosSystem "dn42-il-gw1";
      dn42-il-gw5 = generateNixosSystem "dn42-il-gw5";
      dn42-il-gw6 = generateNixosSystem "dn42-il-gw6";
      dn42-ildix-clerie = generateNixosSystem "dn42-ildix-clerie";
      gatekeeper = generateNixosSystem "gatekeeper";
      hydra-1 = generateNixosSystem "hydra-1";
      hydra-2 = generateNixosSystem "hydra-2";
      minecraft-2 = generateNixosSystem "minecraft-2";
      monitoring-3 = generateNixosSystem "monitoring-3";
      nonat = generateNixosSystem "nonat";
      osmium = generateNixosSystem "osmium";
      palladium = generateNixosSystem "palladium";
      porter = generateNixosSystem "porter";
      schule = generateNixosSystem "schule";
      storage-2 = generateNixosSystem "storage-2";
      web-2 = generateNixosSystem "web-2";
      dn42-ildix-service = generateNixosSystem "dn42-ildix-service";
      astatine = generateNixosSystem "astatine";
      _iso = generateNixosSystem "_iso";
    };

    colmena = {
      meta = {
        nixpkgs = import nixpkgs {};
      };
    } // helper.mapToColmenaHosts self.nixosConfigurations;

    packages.x86_64-linux = let
      pkgs = import nixpkgs {
        overlays = [
          (import ./pkgs/overlay.nix)
        ];
        system = "x86_64-linux";
      };
    in {
      inherit (pkgs)
        anycast_healthchecker
        flask-excel
        iot-data
        pyexcel-xlsx
        pyexcel-webio
        uptimestatus
        wetter;
    };

    hydraJobs = {
      inherit (self)
        packages;
      nixosConfigurations = helper.buildHosts self.nixosConfigurations;
      iso = self.nixosConfigurations._iso.config.system.build.isoImage;
    };
  };
}