tools/devshell/setup-mcp-servers

#!/bin/bash
# Copyright 2025 The Fuchsia Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

# Registers or removes a set of MCP servers from the gemini extension settings.

source "$(cd "$(dirname "${BASH_SOURCE[0]}")" >/dev/null 2>&1 && pwd)"/lib/vars.sh || exit $?
fx-config-read

show_help() {
  cat <<EOF
Usage: $0 [options]

Options:
  --project-only  Apply settings to the project only (~/fuchsia/.gemini/settings.json).
  --extension     Install as a self-contained extension (in ~/.gemini/extensions/).
  --uninstall     Uninstall the MCP servers.
  --help          Show this help message.
EOF
}

install_extensions() {
  if command -v gemini &> /dev/null; then
    GEMINI_CMD="gemini"
  elif [ -x "/google/bin/releases/gemini-cli/tools/gemini" ]; then
    GEMINI_CMD="/google/bin/releases/gemini-cli/tools/gemini"
  else
    fx-error "Error: 'gemini' executable not found. You might need to run gcert."
    exit 1
  fi

  # TODO(b/442696047) remove this extra flag when gemini unbreaks extensions in the internal binary
  if [[ -x "/google/bin/releases/gemini-cli/tools/gemini" ]]; then
    $GEMINI_CMD --noenable_sawmill_logging extensions link $FUCHSIA_DIR/.gemini/extensions/rust
  else
    $GEMINI_CMD extensions link .gemini/extensions/rust
  fi
}

uninstall_extensions() {
  # `gemini extensions` doesn't have an `unlink` subcommand?!
  echo -n "Removing rust extension from home directory... "
  rm -r $HOME/.gemini/extensions/rust
  echo "done."
}

PROJECT_ONLY=false
UNINSTALL=false
EXTENSION_MODE=false
for arg in "$@"; do
  case "$arg" in
    --project-only)
      PROJECT_ONLY=true
      shift
      ;;
    --uninstall)
      UNINSTALL=true
      shift
      ;;
    --extension)
      EXTENSION_MODE=true
      shift
      ;;
    --help)
      show_help
      exit 0
      ;;
  esac
done

if [[ "${EXTENSION_MODE}" == "true" ]]; then
    SETTINGS_PATH="${HOME}/.gemini/extensions/fuchsia/gemini-extension.json"
    mkdir -p "$(dirname "${SETTINGS_PATH}")"
elif [[ "${PROJECT_ONLY}" == "true" ]]; then
    SETTINGS_PATH="${FUCHSIA_DIR}/.gemini/settings.json"
    mkdir -p "$(dirname "${SETTINGS_PATH}")"
else
    SETTINGS_PATH="${HOME}/.gemini/settings.json"
    mkdir -p "$(dirname "${SETTINGS_PATH}")"
fi

PYTHON_SCRIPT="$(cd "$(dirname "${BASH_SOURCE[0]}")" >/dev/null 2>&1 && pwd)/python/setup_mcp_servers.py"
PYTHON_ARGS=("${SETTINGS_PATH}" "${FUCHSIA_DIR}")

if [[ "${UNINSTALL}" == "true" ]]; then
    PYTHON_ARGS+=("--uninstall")
    uninstall_extensions
else
    install_extensions
fi

if [[ "${EXTENSION_MODE}" == "true" ]]; then
    PYTHON_ARGS+=("--extension")
fi

"${PYTHON_SCRIPT}" "${PYTHON_ARGS[@]}"