{
  description = "";
  inputs = { 
    config.url = "./config";
    playground.url = "./playground/example/service"; 
  };
  outputs = { self, config, playground }:
    let
      version = "0.0.1";
      name = "develnixos";

      forAllSystems = config.forAllSystems;
      nixpkgsFor = config.nixpkgsFor;
      devTaskScripts = forAllSystems (system: {
        autoTag = nixpkgsFor.${system}.writeScript "auto_tag.sh" ''
          git tag --force v${version}
          git push origin v${version}
        '';
      });
    in rec {
      packages = playground.packages;

      apps = forAllSystems (system:
        let
          updateLockScript =
            nixpkgsFor.${system}.writeShellScriptBin "update_flake_lock.sh" ''
              nix --experimental-features 'nix-command flakes' flake lock --update-input nixpkgs
              nix --experimental-features 'nix-command flakes' build 
            '';
        in {
          default = {
            type = "app";
            program = "${packages.${system}.default}/bin/hello.sh";
          };
          devTasks = {
            updateFlakeLock = {
              type = "app";
              program = "${updateLockScript}/bin/update_flake_lock.sh";
            };
            autoTag = {
              type = "app";
              program = "${devTaskScripts.${system}.autoTag}";
            };
          };
        });

      devShells = forAllSystems (system: {
        default = nixpkgsFor.${system}.mkShell {
          name = "dev-shell";
          packages = [ nixpkgsFor.${system}.nixfmt ];
          shellHook = ''
            . ./alias.sh
          '';
        };
      });

    };
}