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

  outputs = { self, nixpkgs, flake-utils }:
    flake-utils.lib.eachDefaultSystem
      (system:
        let pkgs = nixpkgs.legacyPackages.${system};
        in { devShell = pkgs.mkShell {
          buildInputs = with pkgs; [
            (pkgs.python3.withPackages (pythonPackages: with pythonPackages; [
              sqlite
              watchexec
            ]))
          ];
          shellHook = ''
            export HOST="127.0.0.1"
            export PORT="8080"
            export KEY="1234"
          '';
        }; }
      );
}