{
  description = "Forgejo CI Runners";

  inputs = {
    # NixOS nixpkgs 24.05
    nixpkgs.url = "github:nixos/nixpkgs/nixos-24.05";

    # Lix - Substitution of the Nix package manager, focused on correctness, usability, and growth – and committed to doing right by its community.
    # https://git.lix.systems/lix-project/lix
    lix-module = {
      url = "https://git.lix.systems/lix-project/nixos-module/archive/2.91.0.tar.gz";
      inputs.nixpkgs.follows = "nixpkgs";
    };

    # srvos - NixOS modules for Hetzner Cloud and other services
    srvos.url = "github:numtide/srvos";

    # disko - NixOS module for managing disks
    disko.url = "github:nix-community/disko";

    # Cachix helper functions for deploying NixOS systems with flakes.
    cachix-deploy-flake.url = "github:cachix/cachix-deploy-flake";

    # Cachix - Nix binary cache hosting and continuous integration
    cachix-flake = {
      url = "github:cachix/cachix";
      inputs.nixpkgs.follows = "nixpkgs";
    };

    # sops-nix - Atomic secret provisioning for NixOS based on sops
    # https://github.com/Mic92/sops-nix
    sops-nix = {
      url = "github:Mic92/sops-nix";
      inputs.nixpkgs.follows = "nixpkgs";
    };
  };

  outputs = { self, sops-nix, nixpkgs, srvos, disko, cachix-flake, cachix-deploy-flake, lix-module, ... }@inputs:
    let
      lib = nixpkgs.lib;
      common = system: rec {
        pkgs = import nixpkgs {
          inherit system;
          overlays = [
            (final: prev: {
              cachix = cachix-flake.packages.${system}.default;
            })
          ];
        };
        cachix-deploy-lib = cachix-deploy-flake.lib pkgs;
      };
      aarch64-linux-modules = [
        sops-nix.nixosModules.sops
        srvos.nixosModules.hardware-hetzner-cloud
        srvos.nixosModules.server
        srvos.nixosModules.mixins-systemd-boot
        disko.nixosModules.disko
        lix-module.nixosModules.default
        ./agents/fj-hetzner-aarch64.nix
        (import ./disko-hetzner-cloud.nix { disks = [ "/dev/sda" ]; })
        {
          boot.loader.efi.canTouchEfiVariables = true;
          networking.hostName = "fj-hetzner-aarch64-01";
          users.users.root.openssh.authorizedKeys.keys =
            [
              "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIBsUe5YF5z8vGcEYtQX7AAiw2rJygGf2l7xxr8nZZa7w jahanson@legiondary"
              "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIJyA/yMPPo+scxBaDFUk7WeEyMAMhXUro5vi4feOKsJT jahanson@durincore"
              "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAILcLI5qN69BuoLp8p7nTYKoLdsBNmZB31OerZ63Car1g jahanson@telchar"
            ];
          services.openssh.enable = true;
          services.openssh.settings.PermitRootLogin = "without-password";
        }
      ];
      x86_64-linux-modules = [
        sops-nix.nixosModules.sops
        ./hardware/shadowfax-kubevirt.nix
        srvos.nixosModules.server
        srvos.nixosModules.mixins-systemd-boot
        disko.nixosModules.disko
        lix-module.nixosModules.default
        ./agents/fj-shadowfax-x86_64.nix
        (import ./disko-shadowfax-kubevirt.nix { disks = [ "/dev/sda" ]; })
        {
          boot.loader.efi.canTouchEfiVariables = true;
          networking.hostName = "fj-shadowfax-01";
          users.users.root.openssh.authorizedKeys.keys =
            [
              "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIBsUe5YF5z8vGcEYtQX7AAiw2rJygGf2l7xxr8nZZa7w jahanson@legiondary"
              "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIJyA/yMPPo+scxBaDFUk7WeEyMAMhXUro5vi4feOKsJT jahanson@durincore"
              "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAILcLI5qN69BuoLp8p7nTYKoLdsBNmZB31OerZ63Car1g jahanson@telchar"
            ];
          services.openssh.enable = true;
          services.openssh.settings.PermitRootLogin = "without-password";
        }
      ];
    in
    {
      # NixOS configurations for manual deployment
      nixosConfigurations =
        {
          "fj-hetzner-aarch64-01" = lib.nixosSystem {
            system = "aarch64-linux";
            specialArgs = { inherit inputs; };
            modules = aarch64-linux-modules;
          };

          "fj-shadowfax-01" = lib.nixosSystem {
            system = "x86_64-linux";
            specialArgs = { inherit inputs; };
            modules = x86_64-linux-modules;
          };
        };
      # Cachix deploy for automated deployments
      packages.aarch64-linux.default =
        let
          inherit (common "aarch64-linux") cachix-deploy-lib;
        in
        cachix-deploy-lib.nixos {
          # system = "aarch64-linux";
          imports = aarch64-linux-modules;
        };
      packages.x86_64-linux.default =
        let
          inherit (common "x86_64-linux") cachix-deploy-lib;
        in
        cachix-deploy-lib.nixos {
          imports = x86_64-linux-modules;
        };

      # Constructs a deploy.json output that can be used to deploy the runners
      # https://docs.cachix.org/deploy/reference#deploy-json

      deploy-json =
        {
          "aarch64-linux" =
            let
              inherit (common "aarch64-linux") cachix-deploy-lib;
            in
            cachix-deploy-lib.spec
              {
                agents = {
                  "fj-hetzner-aarch64-01" =
                    let
                      inherit (common "aarch64-linux") cachix-deploy-lib;
                    in
                    cachix-deploy-lib.nixos {
                      # system = "aarch64-linux";
                      imports = aarch64-linux-modules;
                    };
                };
              };
          "x86_64-linux" =
            let
              inherit (common "x86_64-linux") cachix-deploy-lib;
            in
            cachix-deploy-lib.spec
              {
                agents = {
                  "fj-shadowfax-01" =
                    let
                      inherit (common "x86_64-linux") cachix-deploy-lib;
                    in
                    cachix-deploy-lib.nixos {
                      imports = x86_64-linux-modules;
                    };
                };
              };
        };

      # Convenience output that aggregates the outputs for home, nixos.
      # Also used in ci to build targets generally. 
      top =
        let
          nixtop = nixpkgs.lib.genAttrs
            (builtins.attrNames inputs.self.nixosConfigurations)
            (attr: inputs.self.nixosConfigurations.${attr}.config.system.build.toplevel);
        in
        nixtop;
    };
}