GCP MCP

Instructions

    List active Google Cloud credentials.
    
    Returns:
        List of active credentials and the current default account
    

Implementation Reference

• src/gcp_mcp/gcp_modules/auth/tools.py:147-214 (handler)

  The handler function for the 'auth_list' MCP tool. It lists active Google Cloud credentials by checking application default credentials (ADC), extracting account info, and scanning gcloud credentials directory for additional accounts.

  def auth_list() -> str:
      """
      List active Google Cloud credentials.
      
      Returns:
          List of active credentials and the current default account
      """
      try:
          import google.auth
          
          # Check application default credentials
          try:
              credentials, project = google.auth.default()
              
              # Try to get email from credentials
              email = None
              if hasattr(credentials, 'service_account_email'):
                  email = credentials.service_account_email
              elif hasattr(credentials, 'refresh_token') and credentials.refresh_token:
                  # This is a user credential
                  adc_path = _get_adc_path()
                  if os.path.exists(adc_path):
                      try:
                          with open(adc_path, 'r') as f:
                              data = json.load(f)
                              if 'refresh_token' in data:
                                  # This is a user auth, but we can't get the email directly
                                  email = "User account (ADC)"
                      except:
                          pass
              
              credential_type = type(credentials).__name__
              
              output = "Active Credentials:\n"
              if email:
                  output += f"- {email} (Application Default Credentials, type: {credential_type})\n"
              else:
                  output += f"- Application Default Credentials (type: {credential_type})\n"
              
              if project:
                  output += f"\nCurrent Project: {project}\n"
              else:
                  output += "\nNo project set in default credentials.\n"
              
              # Check for other credentials in well-known locations
              credentials_dir = os.path.expanduser("~/.config/gcloud/credentials")
              if os.path.isdir(credentials_dir):
                  cred_files = [f for f in os.listdir(credentials_dir) if f.endswith('.json')]
                  if cred_files:
                      output += "\nOther available credentials:\n"
                      for cred_file in cred_files:
                          try:
                              with open(os.path.join(credentials_dir, cred_file), 'r') as f:
                                  data = json.load(f)
                                  if 'client_id' in data:
                                      output += f"- User account ({cred_file})\n"
                                  elif 'private_key_id' in data:
                                      output += f"- Service account: {data.get('client_email', 'Unknown')} ({cred_file})\n"
                          except:
                              output += f"- Unknown credential type ({cred_file})\n"
              
              return output
          except Exception as e:
              return f"No active credentials found. Please run auth_login() to authenticate.\nError: {str(e)}"
              
      except Exception as e:
          return f"Error listing credentials: {str(e)}"

• src/gcp_mcp/server.py:30-30 (registration)

  Registration of authentication tools (including auth_list) by calling register_tools on the auth_tools module in the main GCP MCP server.

  auth_tools.register_tools(mcp)

• src/gcp_mcp/server.py:16-16 (registration)

  Import of the auth tools module in the main server.py, aliased as auth_tools, which provides the register_tools function.

  from .gcp_modules.auth import tools as auth_tools

• src/gcp_mcp/gcp_modules/auth/tools.py:359-365 (helper)

  Helper function used by auth_list to determine the path to the application default credentials (ADC) file.

  def _get_adc_path() -> str:
      """Get the path to the application default credentials file."""
      # Standard ADC paths by platform
      if os.name == 'nt':  # Windows
          return os.path.join(os.environ.get('APPDATA', ''), 'gcloud', 'application_default_credentials.json')
      else:  # Linux/Mac
          return os.path.expanduser('~/.config/gcloud/application_default_credentials.json')