{
  description = "NixOS configurations for servers";

  inputs = {
    # Nixos pkgs 23.05
    nixpkgs.url = "github:nixos/nixpkgs/nixos-23.05";

    # Agenix (for credentials)
    agenix = {
      url = "github:ryantm/agenix";
      inputs.nixpkgs.follows = "nixpkgs";
    };
  };

  outputs = { self, nixpkgs, agenix, ... }:
  {
    nixosConfigurations = {
      freebox-VM = nixpkgs.lib.nixosSystem {
        system = "aarch64-linux";
        modules = [
          ./hosts/freebox-VM/configuration.nix
          { environment.systemPackages = [ agenix.packages.x86_64-linux.default ]; }
          agenix.nixosModules.default
        ];
      };

      virt-manager-VM = nixpkgs.lib.nixosSystem {
        system = "x86_64-linux";
        modules = [
          ./hosts/virt-manager-VM/configuration.nix
          { environment.systemPackages = [ agenix.packages.x86_64-linux.default ]; }
          agenix.nixosModules.default
        ];
      };

      virt-backup-VM = nixpkgs.lib.nixosSystem {
        system = "x86_64-linux";
        modules = [
          ./hosts/virt-backup-VM/configuration.nix
          { environment.systemPackages = [ agenix.packages.x86_64-linux.default ]; }
          agenix.nixosModules.default
        ];
      };
    };
  };
}