update_catalog_item_variable
Modify catalog item variables in ServiceNow by updating labels, requirements, help text, default values, and display order to customize service request forms.
Instructions
Update a catalog item variable
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| variable_id | Yes | The sys_id of the variable to update | |
| label | No | The display label for the variable | |
| mandatory | No | Whether the variable is required | |
| help_text | No | Help text to display with the variable | |
| default_value | No | Default value for the variable | |
| description | No | Description of the variable | |
| order | No | Display order of the variable | |
| reference_qualifier | No | For reference fields, the query to filter reference options | |
| max_length | No | Maximum length for string fields | |
| min | No | Minimum value for numeric fields | |
| max | No | Maximum value for numeric fields |
Implementation Reference
- The handler function that performs the PATCH request to update the catalog item variable in ServiceNow.def update_catalog_item_variable( config: ServerConfig, auth_manager: AuthManager, params: UpdateCatalogItemVariableParams, ) -> CatalogItemVariableResponse: """ Update an existing variable (form field) for a catalog item. Args: config: Server configuration. auth_manager: Authentication manager. params: Parameters for updating a catalog item variable. Returns: Response with information about the updated variable. """ api_url = f"{config.instance_url}/api/now/table/item_option_new/{params.variable_id}" # Build request data with only parameters that are provided data = {} if params.label is not None: data["question_text"] = params.label if params.mandatory is not None: data["mandatory"] = str(params.mandatory).lower() # ServiceNow expects "true"/"false" strings if params.help_text is not None: data["help_text"] = params.help_text if params.default_value is not None: data["default_value"] = params.default_value if params.description is not None: data["description"] = params.description if params.order is not None: data["order"] = params.order if params.reference_qualifier is not None: data["reference_qual"] = params.reference_qualifier if params.max_length is not None: 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 # If no fields to update, return early if not data: return CatalogItemVariableResponse( success=False, message="No update parameters provided", ) # Make request try: response = requests.patch( 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 updated successfully", variable_id=params.variable_id, details=result, ) except requests.RequestException as e: logger.error(f"Failed to update catalog item variable: {e}") return CatalogItemVariableResponse( success=False, message=f"Failed to update catalog item variable: {str(e)}", )
- Pydantic BaseModel defining the input schema/parameters for the tool.class UpdateCatalogItemVariableParams(BaseModel): """Parameters for updating a catalog item variable.""" variable_id: str = Field(..., description="The sys_id of the variable to update") label: Optional[str] = Field(None, description="The display label for the variable") mandatory: Optional[bool] = Field(None, 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_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:471-477 (registration)Central registration of the tool in get_tool_definitions(), specifying the handler alias, input schema, return type hint, description, and serialization method."update_catalog_item_variable": ( update_catalog_item_variable_tool, UpdateCatalogItemVariableParams, Dict[str, Any], # Expects dict "Update a catalog item variable", "dict", # Tool returns Pydantic model ),
- src/servicenow_mcp/tools/__init__.py:18-22 (registration)Import of the handler function into tools/__init__.py for exposure.from servicenow_mcp.tools.catalog_variables import ( create_catalog_item_variable, list_catalog_item_variables, update_catalog_item_variable, )
- src/servicenow_mcp/tools/__init__.py:135-137 (registration)Inclusion in __all__ for public export of the tool function."create_catalog_item_variable", "list_catalog_item_variables", "update_catalog_item_variable",