{
  pkgs,
  lib,
  config,
  inputs,
  ...
}: let
  oopkgs = import inputs.nix-ocaml {system = pkgs.system;};
  opkgs = oopkgs.ocamlPackages;

  ocaml-quickjs = opkgs.buildDunePackage {
    name = "quickjs";
    pname = "quickjs";
    version = "0.1.1";
    # src = pkgs.fetchFromGitHub {
    #   owner = "dhcmrlchtdj";
    #   repo = "ocaml-quickjs";
    #   rev = "master";
    #   sha256 = "sha256-CIMxkElHW6GARt8WKe+mr+G/MNkMfxvP/Q6yI1nFG+M=";
    # };
    # src = inputs.quickjs-ml;
    # src = pkgs.fetchFromGitHub {
    #   fetchSubmodules = true;
    #   owner = "ml-in-barcelona";
    #   repo = "quickjs.ml";
    #   rev = "master";
    #   sha256 = "zS1kBkpg6mipGr8IGS5tRP//Hws5EhDhT1Izc2DuwT0=";
    # };
    src = ./quickjs.ml;
    # src = builtins.fetchurl {
    #   url = "https://github.com/ml-in-barcelona/quickjs.ml?submodules=1";
    #   sha256 = "0szmgj980l3jah5lsz63fpniz34sr5rabhriv0srv58wp8qh858h";
    # };
    doCheck = true;
    buildInputs = [pkgs.git];
    propagatedBuildInputs = [
      pkgs.git
      opkgs.alcotest
      opkgs.integers
      opkgs.ctypes
    ];
  };
  melange-json-native = opkgs.buildDunePackage {
    pname = "melange-json-native";
    version = "1.3.0";
    src = builtins.fetchurl {
      url = "https://github.com/melange-community/melange-json/releases/download/2.0.0/melange-json-2.0.0.tbz";
      sha256 = "1n1avcplidrigkch4y8lnh136g5q06d0xhgzvgips3y399lw2jah";
    };
    propagatedBuildInputs = with opkgs; [ppxlib yojson];
  };
  # server-reason-react = opkgs.buildDunePackage {
  #   pname = "server-reason-react";
  #   version = "0.3.1";
  #   doCheck = true;
  #   # src = ./srr;
  #   src = pkgs.fetchFromGitHub {
  #     owner = "ml-in-barcelona";
  #     repo = "server-reason-react";
  #     rev = "d5dd436b0a447ff0a82f9a8d7a02f102139299a9";
  #     sha256 = "sha256-CIMxkElHW6GARt8WKe+mr+G/MNkMfxvP/Q6yI1nFG+M=";
  #   };
  #   nativeBuildInputs = with opkgs; [
  #     # ocamlformat
  #     reason
  #     melange
  #     reason-native.refmterr
  #   ];
  #   propagatedBuildInputs =
  #     (with opkgs; [
  #       uucp
  #       ocaml-quickjs
  #       yojson
  #       uri
  #       melange
  #       ocaml_pcre
  #       lwt
  #       lwt_ppx
  #       # reason-react
  #       # reason-react-ppx
  #       # melange-json
  #       # melange-json-native
  #       # alcotest-lwt
  #       # ocamlformat
  #     ])
  #     ++ [pkgs.nodejs];
  # };
  # nix-ocaml = inputs.nix-ocaml.legacyPackages.${pkgs.system};
in {
  # https://devenv.sh/packages/
  env.WTF = pkgs.lib.makeLibraryPath config.packages;
  packages =
    (with pkgs; [
      git
      watchexec
      sqlite
      pkg-config
      coreutils-full
    ])
    ++ (with oopkgs; [ocaml opam dune_3])
    ++ [
      /nix/store/0rqfrhc4j7b7d5zqjdp3g3563305q8vs-ocaml5.2.1-server-reason-react-0.4.0
      # server-reason-react
      melange-json-native
    ]
    ++ (with opkgs; [
      base
      core
      utop
      ocamlformat
      ocaml_sqlite3
      eio
      integers
      uri
      yojson
      melange
      dream
      melange-webapi
      melange-fetch
      melange-json
      reason
      reason-react
      ocaml-lsp
      ppx_yojson_conv
    ]);

  # https://devenv.sh/languages/
  languages.javascript = {
    enable = true;
    npm.enable = true;
  };

  # https://devenv.sh/processes/
  # processes.cargo-watch.exec = "cargo-watch";

  # https://devenv.sh/services/
  # services.postgres.enable = true;

  # https://devenv.sh/scripts/
  scripts.hello.exec = ''
    echo hello from $GREET
  '';

  enterShell = ''
    hello
    git --version
  '';

  # https://devenv.sh/tasks/
  # tasks = {
  #   "myproj:setup".exec = "mytool build";
  #   "devenv:enterShell".after = [ "myproj:setup" ];
  # };

  # https://devenv.sh/tests/
  enterTest = ''
    echo "Running tests"
    git --version | grep --color=auto "${pkgs.git.version}"
  '';

  # https://devenv.sh/git-hooks/
  # git-hooks.hooks.shellcheck.enable = true;

  # See full reference at https://devenv.sh/reference/options/
}