ServiceNow MCP Server

Instructions

Implementation Reference

• src/servicenow_mcp/tools/change_tools.py:396-500 (handler)

  The handler function that executes the tool logic: validates params, builds ServiceNow query with filters, makes GET request to /api/now/table/change_request, returns list of change requests.

  def list_change_requests(
      auth_manager: AuthManager,
      server_config: ServerConfig,
      params: Dict[str, Any],
  ) -> Dict[str, Any]:
      """
      List change requests from ServiceNow.
  
      Args:
          auth_manager: The authentication manager.
          server_config: The server configuration.
          params: The parameters for listing change requests.
  
      Returns:
          A list of change requests.
      """
      # Unwrap and validate parameters
      result = _unwrap_and_validate_params(
          params, 
          ListChangeRequestsParams
      )
      
      if not result["success"]:
          return result
      
      validated_params = result["params"]
      
      # Build the query
      query_parts = []
      
      if validated_params.state:
          query_parts.append(f"state={validated_params.state}")
      if validated_params.type:
          query_parts.append(f"type={validated_params.type}")
      if validated_params.category:
          query_parts.append(f"category={validated_params.category}")
      if validated_params.assignment_group:
          query_parts.append(f"assignment_group={validated_params.assignment_group}")
      
      # Handle timeframe filtering
      if validated_params.timeframe:
          now = datetime.now().strftime("%Y-%m-%d %H:%M:%S")
          if validated_params.timeframe == "upcoming":
              query_parts.append(f"start_date>{now}")
          elif validated_params.timeframe == "in-progress":
              query_parts.append(f"start_date<{now}^end_date>{now}")
          elif validated_params.timeframe == "completed":
              query_parts.append(f"end_date<{now}")
      
      # Add any additional query string
      if validated_params.query:
          query_parts.append(validated_params.query)
      
      # Combine query parts
      query = "^".join(query_parts) if query_parts else ""
      
      # 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"
      
      params = {
          "sysparm_limit": validated_params.limit,
          "sysparm_offset": validated_params.offset,
          "sysparm_query": query,
          "sysparm_display_value": "true",
      }
      
      try:
          response = requests.get(url, headers=headers, params=params)
          response.raise_for_status()
          
          result = response.json()
          
          # Handle the case where result["result"] is a list
          change_requests = result.get("result", [])
          count = len(change_requests)
          
          return {
              "success": True,
              "change_requests": change_requests,
              "count": count,
              "total": count,  # Use count as total if total is not provided
          }
      except requests.exceptions.RequestException as e:
          logger.error(f"Error listing change requests: {e}")
          return {
              "success": False,
              "message": f"Error listing change requests: {str(e)}",
          }

• src/servicenow_mcp/tools/change_tools.py:54-65 (schema)

  Pydantic BaseModel defining the input parameters for the list_change_requests tool, including pagination, filters, and custom query.

  class ListChangeRequestsParams(BaseModel):
      """Parameters for listing change requests."""
  
      limit: Optional[int] = Field(10, description="Maximum number of records to return")
      offset: Optional[int] = Field(0, description="Offset to start from")
      state: Optional[str] = Field(None, description="Filter by state")
      type: Optional[str] = Field(None, description="Filter by type (normal, standard, emergency)")
      category: Optional[str] = Field(None, description="Filter by category")
      assignment_group: Optional[str] = Field(None, description="Filter by assignment group")
      timeframe: Optional[str] = Field(None, description="Filter by timeframe (upcoming, in-progress, completed)")
      query: Optional[str] = Field(None, description="Additional query string")

• src/servicenow_mcp/utils/tool_utils.py:493-499 (registration)

  Registers the tool in get_tool_definitions() with handler alias, schema, description, and JSON serialization for MCP server.

  "list_change_requests": (
      list_change_requests_tool,
      ListChangeRequestsParams,
      str,  # Expects JSON string
      "List change requests from ServiceNow",
      "json",  # Tool returns list/dict
  ),

• src/servicenow_mcp/tools/__init__.py:28-28 (registration)

  Re-exports the list_change_requests function from change_tools for use in tool_utils.

  list_change_requests,

• src/servicenow_mcp/tools/change_tools.py:107-159 (helper)

  Helper function used by the handler to unwrap, validate input parameters against the Pydantic schema, and handle common input formats.

  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)}",
          }