AWS FIS MCP Server

Instructions

Stop a running AWS FIS experiment.

Args:
    experiment_id: ID of the experiment to stop
    region: AWS region to use (default: us-east-1)
    
Returns:
    JSON string containing the stopped experiment information

Implementation Reference

• aws_fis_mcp/tools.py:214-237 (handler)

  The core handler function for the 'stop_experiment' tool. It uses boto3 to call AWS FIS stop_experiment API, serializes the response with datetime handling, and returns JSON. Protected by write mode decorator.

  @require_write_mode
  def stop_experiment(experiment_id: str, region: str = "us-east-1") -> str:
      """
      Stop a running AWS FIS experiment.
      
      Args:
          experiment_id: ID of the experiment to stop
          region: AWS region to use (default: us-east-1)
          
      Returns:
          JSON string containing the stopped experiment information
      """
      try:
          fis = boto3.client('fis', region_name=region)
          response = fis.stop_experiment(id=experiment_id)
          
          # Get the raw experiment data and serialize datetime objects
          experiment = response.get('experiment', {})
          serialized_experiment = _serialize_datetime(experiment)
          
          return json.dumps(serialized_experiment, indent=2)
      except Exception as e:
          return f"Error stopping experiment: {str(e)}"

• aws_fis_mcp/server.py:30-30 (registration)

  Registration of the stop_experiment tool handler using FastMCP app.tool() decorator.

  app.tool()(stop_experiment)

• aws_fis_mcp/tools.py:34-52 (helper)

  Helper function used by stop_experiment to recursively serialize datetime objects in the response to ISO strings for JSON output.

  def _serialize_datetime(obj: Any) -> Any:
      """
      Recursively serialize datetime objects to ISO format strings.
      
      Args:
          obj: Object that may contain datetime objects
          
      Returns:
          Object with datetime objects converted to ISO format strings
      """
      if isinstance(obj, datetime):
          return obj.isoformat()
      elif isinstance(obj, dict):
          return {key: _serialize_datetime(value) for key, value in obj.items()}
      elif isinstance(obj, list):
          return [_serialize_datetime(item) for item in obj]
      else:
          return obj

• aws_fis_mcp/tools.py:19-31 (helper)

  Decorator applied to stop_experiment requiring write mode to be enabled for execution, preventing accidental destructive actions.

  def require_write_mode(func):
      """Decorator to require write mode for destructive operations."""
      @wraps(func)
      def wrapper(*args, **kwargs):
          if not _WRITE_MODE_ENABLED:
              return json.dumps({
                  "error": "Write operations are disabled",
                  "message": f"The '{func.__name__}' operation requires write mode. Please restart the server with --allow-writes flag to enable write operations.",
                  "operation": func.__name__,
                  "read_only_mode": True
              }, indent=2)
          return func(*args, **kwargs)
      return wrapper

• aws_fis_mcp/server.py:7-19 (registration)

  Import statement bringing the stop_experiment handler into the server module for registration.

  from aws_fis_mcp.tools import (
      list_experiment_templates,
      get_experiment_template,
      list_experiments,
      get_experiment,
      start_experiment,
      stop_experiment,
      create_experiment_template,
      delete_experiment_template,
      list_action_types,
      generate_template_example,
      set_write_mode,
  )