{
  description = "puzzleYOU release action";

  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-25.05";
    flake-utils.url = "github:numtide/flake-utils";
  };

  outputs = { self, nixpkgs, flake-utils, ... }:
    flake-utils.lib.eachDefaultSystem (system:
      let
        pkgs = import nixpkgs { inherit system; };

        python = pkgs.python313.withPackages (ps: with ps; [
          isort
          flake8
          semver
          toml
        ]);

        pythonPackage = pkgs.python3Packages.buildPythonPackage {
          name = "release-action";
          src = ./.;
        };
      in
        {
          devShells.default = pkgs.mkShell {
            buildInputs = [
              pkgs.envsubst
              pkgs.just
              pkgs.gitea-actions-runner
              python
            ];
          };

          packages.default = pkgs.writers.writePython3Bin
            "release-action"
            {
              libraries = with pkgs.python3Packages; [
                semver # TODO move to setup.py?
                toml
                pythonPackage
              ];
            }
            (builtins.readFile ./src/main.py)
          ;
        }
    );
}