ServiceNow MCP Server

Instructions

Implementation Reference

• src/servicenow_mcp/tools/workflow_tools.py:300-357 (handler)

  The core handler function for the 'list_workflow_versions' tool. It validates parameters using ListWorkflowVersionsParams, constructs a ServiceNow API query for the wf_workflow_version table filtered by workflow_id, fetches the data via REST GET, and returns versions list with metadata.

  def list_workflow_versions(
      auth_manager: AuthManager,
      server_config: ServerConfig,
      params: Dict[str, Any],
  ) -> Dict[str, Any]:
      """
      List versions of a specific workflow.
      
      Args:
          auth_manager: Authentication manager
          server_config: Server configuration
          params: Parameters for listing workflow versions
          
      Returns:
          Dict[str, Any]: List of workflow versions
      """
      # Unwrap parameters if needed
      params = _unwrap_params(params, ListWorkflowVersionsParams)
      
      # Get the correct auth_manager and server_config
      try:
          auth_manager, server_config = _get_auth_and_config(auth_manager, server_config)
      except ValueError as e:
          logger.error(f"Error getting auth and config: {e}")
          return {"error": str(e)}
      
      workflow_id = params.get("workflow_id")
      if not workflow_id:
          return {"error": "Workflow ID is required"}
      
      # Convert parameters to ServiceNow query format
      query_params = {
          "sysparm_query": f"workflow={workflow_id}",
          "sysparm_limit": params.get("limit", 10),
          "sysparm_offset": params.get("offset", 0),
      }
      
      # Make the API request
      try:
          headers = auth_manager.get_headers()
          url = f"{server_config.instance_url}/api/now/table/wf_workflow_version"
          
          response = requests.get(url, headers=headers, params=query_params)
          response.raise_for_status()
          
          result = response.json()
          return {
              "versions": result.get("result", []),
              "count": len(result.get("result", [])),
              "total": int(response.headers.get("X-Total-Count", 0)),
              "workflow_id": workflow_id,
          }
      except requests.RequestException as e:
          logger.error(f"Error listing workflow versions: {e}")
          return {"error": str(e)}
      except Exception as e:
          logger.error(f"Unexpected error listing workflow versions: {e}")
          return {"error": str(e)}

• src/servicenow_mcp/tools/workflow_tools.py:40-46 (schema)

  Pydantic BaseModel defining the input schema for the tool: requires workflow_id, optional limit and offset.

  class ListWorkflowVersionsParams(BaseModel):
      """Parameters for listing workflow versions."""
      
      workflow_id: str = Field(..., description="Workflow ID or sys_id")
      limit: Optional[int] = Field(10, description="Maximum number of records to return")
      offset: Optional[int] = Field(0, description="Offset to start from")

• src/servicenow_mcp/utils/tool_utils.py:550-556 (registration)

  Registers the tool in the central get_tool_definitions() dictionary used by the MCP server, mapping name to (handler, param_model, return_type, description, serialization).

  "list_workflow_versions": (
      list_workflow_versions_tool,
      ListWorkflowVersionsParams,
      str,  # Expects JSON string
      "List workflow versions from ServiceNow",
      "json",  # Tool returns list/dict
  ),

• src/servicenow_mcp/tools/__init__.py:78-91 (registration)

  Imports the list_workflow_versions function into the tools package namespace for exposure.

  from servicenow_mcp.tools.workflow_tools import (
      activate_workflow,
      add_workflow_activity,
      create_workflow,
      deactivate_workflow,
      delete_workflow_activity,
      get_workflow_activities,
      get_workflow_details,
      list_workflow_versions,
      list_workflows,
      reorder_workflow_activities,
      update_workflow,
      update_workflow_activity,
  )

• src/servicenow_mcp/tools/workflow_tools.py:126-136 (helper)

  Helper function used by the handler to unwrap and validate parameters using the schema model.

  def _unwrap_params(params: Any, param_class: Type[T]) -> Dict[str, Any]:
      """
      Unwrap parameters if they're wrapped in a Pydantic model.
      This helps handle cases where the parameters are passed as a model instead of a dict.
      """
      if isinstance(params, dict):
          return params
      if isinstance(params, param_class):
          return params.dict(exclude_none=True)
      return params