{
  description = "A simple Go program for switching windows on Sway wm";

  # Nixpkgs / NixOS version to use.
  inputs.nixpkgs.url = "nixpkgs/nixos-unstable";

  outputs = {
    self,
    nixpkgs,
  }: let
    # to work with older version of flakes
    lastModifiedDate = self.lastModifiedDate or self.lastModified or "19700101";

    # Generate a user-friendly version number.
    version = builtins.substring 0 8 lastModifiedDate;

    # System types to support.
    supportedSystems = ["x86_64-linux" "aarch64-linux"];

    # Helper function to generate an attrset '{ x86_64-linux = f "x86_64-linux"; ... }'.
    forAllSystems = nixpkgs.lib.genAttrs supportedSystems;

    # Nixpkgs instantiated for supported system types.
    nixpkgsFor = forAllSystems (system: import nixpkgs {inherit system;});
  in {
    # Provide some binary packages for selected system types.
    packages = forAllSystems (system: let
      pkgs = nixpkgsFor.${system};
    in {
      swaysw = pkgs.buildGoModule {
        pname = "swaysw";
        inherit version;
        src = ./.;
        ldFlags = ["-s -w"];
        vendorSha256 = null;

      };
    });

    devShells = forAllSystems (system: let
      pkgs = nixpkgsFor.${system};
    in {
      default = pkgs.mkShell {
        buildInputs = with pkgs; [go gopls gotools go-tools wofi];
      };
    });

    defaultPackage = forAllSystems (system: self.packages.${system}.swaysw);
  };
}