{
  description = "Lean Wayland API for Lean";
  inputs = {
    nixpkgs = {
      url = "github:nixos/nixpkgs/nixpkgs-unstable";
    };
    flake-utils = {
      url = "github:numtide/flake-utils";
    };
  };
  outputs = { self, nixpkgs, flake-utils }: flake-utils.lib.eachDefaultSystem (system:
    let
      pkgs = import nixpkgs {
        inherit system;
        config.allowUnsupportedSystem = true; # for macOS
      };
      lean-shell = pkgs.mkShell {
        name = "Lean";
        packages = [ pkgs.lean4 pkgs.wayland pkgs.pkg-config ];
        shellHook = pkgs.lib.optionalString pkgs.stdenv.isDarwin ''
          export XDG_RUNTIME_DIR="$(pwd)/server"
        '';
      };
    in {
    devShells = {
      default = lean-shell;
      lean = lean-shell;
    };
  });
}