ServiceNow MCP Server

Instructions

Implementation Reference

• src/servicenow_mcp/tools/catalog_variables.py:81-152 (handler)

  The function implementing the core logic of the 'create_catalog_item_variable' tool. It constructs a POST request to the ServiceNow 'item_option_new' table API and handles the response.
  def create_catalog_item_variable( config: ServerConfig, auth_manager: AuthManager, params: CreateCatalogItemVariableParams, ) -> CatalogItemVariableResponse: """ Create a new variable (form field) for a catalog item. Args: config: Server configuration. auth_manager: Authentication manager. params: Parameters for creating a catalog item variable. Returns: Response with information about the created variable. """ api_url = f"{config.instance_url}/api/now/table/item_option_new" # Build request data data = { "cat_item": params.catalog_item_id, "name": params.name, "type": params.type, "question_text": params.label, "mandatory": str(params.mandatory).lower(), # ServiceNow expects "true"/"false" strings } if params.help_text: data["help_text"] = params.help_text if params.default_value: data["default_value"] = params.default_value if params.description: data["description"] = params.description if params.order is not None: data["order"] = params.order if params.reference_table: data["reference"] = params.reference_table if params.reference_qualifier: data["reference_qual"] = params.reference_qualifier if params.max_length: data["max_length"] = params.max_length if params.min is not None: data["min"] = params.min if params.max is not None: data["max"] = params.max # Make request try: response = requests.post( api_url, json=data, headers=auth_manager.get_headers(), timeout=config.timeout, ) response.raise_for_status() result = response.json().get("result", {}) return CatalogItemVariableResponse( success=True, message="Catalog item variable created successfully", variable_id=result.get("sys_id"), details=result, ) except requests.RequestException as e: logger.error(f"Failed to create catalog item variable: {e}") return CatalogItemVariableResponse( success=False, message=f"Failed to create catalog item variable: {str(e)}", )
• src/servicenow_mcp/tools/catalog_variables.py:19-36 (schema)

  Pydantic BaseModel defining the input parameters and validation schema for the create_catalog_item_variable tool.
  class CreateCatalogItemVariableParams(BaseModel): """Parameters for creating a catalog item variable.""" catalog_item_id: str = Field(..., description="The sys_id of the catalog item") name: str = Field(..., description="The name of the variable (internal name)") type: str = Field(..., description="The type of variable (e.g., string, integer, boolean, reference)") label: str = Field(..., description="The display label for the variable") mandatory: bool = Field(False, description="Whether the variable is required") help_text: Optional[str] = Field(None, description="Help text to display with the variable") default_value: Optional[str] = Field(None, description="Default value for the variable") description: Optional[str] = Field(None, description="Description of the variable") order: Optional[int] = Field(None, description="Display order of the variable") reference_table: Optional[str] = Field(None, description="For reference fields, the table to reference") reference_qualifier: Optional[str] = Field(None, description="For reference fields, the query to filter reference options") max_length: Optional[int] = Field(None, description="Maximum length for string fields") min: Optional[int] = Field(None, description="Minimum value for numeric fields") max: Optional[int] = Field(None, description="Maximum value for numeric fields")
• src/servicenow_mcp/utils/tool_utils.py:457-463 (registration)

  The tool registration entry in the get_tool_definitions() function's dictionary, specifying the handler, schema, description, and serialization for MCP integration.
  "create_catalog_item_variable": ( create_catalog_item_variable_tool, CreateCatalogItemVariableParams, Dict[str, Any], # Expects dict "Create a new catalog item variable", "dict", # Tool returns Pydantic model ),
• src/servicenow_mcp/tools/__init__.py:18-22 (registration)

  Import statement exposing the create_catalog_item_variable function from its module for use in the tools package.
  from servicenow_mcp.tools.catalog_variables import ( create_catalog_item_variable, list_catalog_item_variables, update_catalog_item_variable, )
• src/servicenow_mcp/utils/tool_utils.py:41-48 (schema)

  Import of the CreateCatalogItemVariableParams schema and aliased handler function used in tool registration.
  from servicenow_mcp.tools.catalog_variables import ( CreateCatalogItemVariableParams, ListCatalogItemVariablesParams, UpdateCatalogItemVariableParams, ) from servicenow_mcp.tools.catalog_variables import ( create_catalog_item_variable as create_catalog_item_variable_tool, )