ServiceNow MCP Server

Instructions

Implementation Reference

• src/servicenow_mcp/tools/change_tools.py:502-581 (handler)

  The handler function implementing the core logic for retrieving change request details, including associated tasks, via ServiceNow REST API.
  def get_change_request_details( auth_manager: AuthManager, server_config: ServerConfig, params: Dict[str, Any], ) -> Dict[str, Any]: """ Get details of a change request from ServiceNow. Args: auth_manager: The authentication manager. server_config: The server configuration. params: The parameters for getting change request details. Returns: The change request details. """ # Unwrap and validate parameters result = _unwrap_and_validate_params( params, GetChangeRequestDetailsParams, required_fields=["change_id"] ) if not result["success"]: return result validated_params = result["params"] # Get the instance URL instance_url = _get_instance_url(auth_manager, server_config) if not instance_url: return { "success": False, "message": "Cannot find instance_url in either server_config or auth_manager", } # Get the headers headers = _get_headers(auth_manager, server_config) if not headers: return { "success": False, "message": "Cannot find get_headers method in either auth_manager or server_config", } # Make the API request url = f"{instance_url}/api/now/table/change_request/{validated_params.change_id}" params = { "sysparm_display_value": "true", } try: response = requests.get(url, headers=headers, params=params) response.raise_for_status() result = response.json() # Get tasks associated with this change request tasks_url = f"{instance_url}/api/now/table/change_task" tasks_params = { "sysparm_query": f"change_request={validated_params.change_id}", "sysparm_display_value": "true", } tasks_response = requests.get(tasks_url, headers=headers, params=tasks_params) tasks_response.raise_for_status() tasks_result = tasks_response.json() return { "success": True, "change_request": result["result"], "tasks": tasks_result["result"], } except requests.exceptions.RequestException as e: logger.error(f"Error getting change request details: {e}") return { "success": False, "message": f"Error getting change request details: {str(e)}", }
• src/servicenow_mcp/tools/change_tools.py:67-71 (schema)

  Pydantic model defining the input schema for the get_change_request_details tool, requiring a change_id.
  class GetChangeRequestDetailsParams(BaseModel): """Parameters for getting change request details.""" change_id: str = Field(..., description="Change request ID or sys_id")
• src/servicenow_mcp/utils/tool_utils.py:500-506 (registration)

  Registration of the tool in the central tool_definitions dictionary used by the MCP server, mapping name to function, schema, description, etc.
  "get_change_request_details": ( get_change_request_details_tool, GetChangeRequestDetailsParams, str, # Expects JSON string "Get detailed information about a specific change request", "json", # Tool returns list/dict ),
• src/servicenow_mcp/tools/__init__.py:27-27 (registration)

  Re-export of the get_change_request_details function from change_tools.py for convenient access.
  get_change_request_details,
• src/servicenow_mcp/tools/change_tools.py:107-159 (helper)

  Shared helper function used by get_change_request_details (and other tools) for parameter validation and unwrapping.
  def _unwrap_and_validate_params(params: Any, model_class: Type[T], required_fields: List[str] = None) -> Dict[str, Any]: """ Helper function to unwrap and validate parameters. Args: params: The parameters to unwrap and validate. model_class: The Pydantic model class to validate against. required_fields: List of required field names. Returns: A tuple of (success, result) where result is either the validated parameters or an error message. """ # Handle case where params might be wrapped in another dictionary if isinstance(params, dict) and len(params) == 1 and "params" in params and isinstance(params["params"], dict): logger.warning("Detected params wrapped in a 'params' key. Unwrapping...") params = params["params"] # Handle case where params might be a Pydantic model object if not isinstance(params, dict): try: # Try to convert to dict if it's a Pydantic model logger.warning("Params is not a dictionary. Attempting to convert...") params = params.dict() if hasattr(params, "dict") else dict(params) except Exception as e: logger.error(f"Failed to convert params to dictionary: {e}") return { "success": False, "message": f"Invalid parameters format. Expected a dictionary, got {type(params).__name__}", } # Validate required parameters are present if required_fields: for field in required_fields: if field not in params: return { "success": False, "message": f"Missing required parameter '{field}'", } try: # Validate parameters against the model validated_params = model_class(**params) return { "success": True, "params": validated_params, } except Exception as e: logger.error(f"Error validating parameters: {e}") return { "success": False, "message": f"Error validating parameters: {str(e)}", }