{
  lib,
  stdenv,
  rustPlatform,
  fetchFromGitHub,
  pkg-config,
  openssl,
  cmake,
  libx11,
  libxtst,
  llvmPackages,
}:

rustPlatform.buildRustPackage rec {
  pname = "g3";
  # Upstream has no git tags or releases; pin main and let nix-update
  # track the branch. Version shape matches nix-update --version=branch=main
  # for a tagless repository (package version is 0.1.0 upstream).
  version = "0.1.0-unstable-2026-09-06";

  src = fetchFromGitHub {
    owner = "dhanji";
    repo = "g3";
    rev = "9793144520d290a9ea621a06cf7d8322e6fa4a35";
    hash = "sha256-s4QlOah7ffoFjiTw2nO/SbCbvIRxr4HB/3pOpQpGWRM=";
  };

  # Cargo.lock has a git dependency (tree-sitter-haskell); cargoHash /
  # fetchCargoVendor covers registry + git sources.
  cargoHash = "sha256-6dvN4//NNuo9s5QzTcrxYiNkxP0Ivysg6f1F9soFrL4=";

  nativeBuildInputs = [
    pkg-config
    cmake
    # llama-cpp-sys-2 runs bindgen, which needs libclang.
    llvmPackages.libclang
  ];

  buildInputs = [
    openssl
    libx11
    libxtst
  ];

  # bindgen (via llama-cpp-sys-2) needs libclang and the C library headers.
  env = {
    LIBCLANG_PATH = "${llvmPackages.libclang.lib}/lib";
    BINDGEN_EXTRA_CLANG_ARGS = "-isystem ${lib.getDev stdenv.cc.libc}/include";
  };

  # Root package only builds/installs its own bins; studio is a sibling
  # workspace member. Match upstream install.sh: ship g3 and studio
  # (renamed to g3-studio).
  cargoBuildFlags = [
    "-p"
    "g3"
    "-p"
    "studio"
  ];
  cargoInstallFlags = [
    "-p"
    "g3"
    "-p"
    "studio"
  ];

  # Provider and computer-control tests need network, LLM credentials, and a
  # display; not runnable in the Nix sandbox.
  doCheck = false;

  # Upstream install.sh names the companion workspace manager g3-studio.
  postInstall = ''
    mv "$out/bin/studio" "$out/bin/g3-studio"
  '';

  passthru = {
    category = "AI Coding Agents";
    updateScript = [
      "nix-update"
      "--flake"
      ".#g3"
      "--version=branch=main"
    ];
  };

  meta = with lib; {
    description = "AI coding agent that writes code and executes commands, with multi-provider LLM support, context compaction, and desktop automation";
    homepage = "https://github.com/dhanji/g3";
    # Cargo.toml declares MIT; the repository ships no LICENSE file.
    license = licenses.mit;
    sourceProvenance = with sourceTypes; [ fromSource ];
    mainProgram = "g3";
    platforms = platforms.unix;
  };
}