ServiceNow MCP Server

Instructions

Implementation Reference

• src/servicenow_mcp/tools/change_tools.py:860-958 (handler)

  The main handler function implementing the reject_change tool. It validates parameters using RejectChangeParams, finds the approval record, updates it to rejected state with reason, and sets the change request state to canceled with work notes.

  def reject_change(
      auth_manager: AuthManager,
      server_config: ServerConfig,
      params: Dict[str, Any],
  ) -> Dict[str, Any]:
      """
      Reject a change request in ServiceNow.
  
      Args:
          auth_manager: The authentication manager.
          server_config: The server configuration.
          params: The parameters for rejecting a change request.
  
      Returns:
          The result of the rejection.
      """
      # Unwrap and validate parameters
      result = _unwrap_and_validate_params(
          params, 
          RejectChangeParams,
          required_fields=["change_id", "rejection_reason"]
      )
      
      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",
          }
      
      # First, find the approval record
      approval_query_url = f"{instance_url}/api/now/table/sysapproval_approver"
      
      query_params = {
          "sysparm_query": f"document_id={validated_params.change_id}",
          "sysparm_limit": 1,
      }
      
      try:
          approval_response = requests.get(approval_query_url, headers=headers, params=query_params)
          approval_response.raise_for_status()
          
          approval_result = approval_response.json()
          
          if not approval_result.get("result") or len(approval_result["result"]) == 0:
              return {
                  "success": False,
                  "message": "No approval record found for this change request",
              }
          
          approval_id = approval_result["result"][0]["sys_id"]
          
          # Now, update the approval record to rejected
          approval_update_url = f"{instance_url}/api/now/table/sysapproval_approver/{approval_id}"
          headers["Content-Type"] = "application/json"
          
          approval_data = {
              "state": "rejected",
              "comments": validated_params.rejection_reason,
          }
          
          approval_update_response = requests.patch(approval_update_url, json=approval_data, headers=headers)
          approval_update_response.raise_for_status()
          
          # Finally, update the change request state to "canceled"
          change_url = f"{instance_url}/api/now/table/change_request/{validated_params.change_id}"
          
          change_data = {
              "state": "canceled",  # This may vary depending on ServiceNow configuration
              "work_notes": f"Change request rejected: {validated_params.rejection_reason}",
          }
          
          change_response = requests.patch(change_url, json=change_data, headers=headers)
          change_response.raise_for_status()
          
          return {
              "success": True,
              "message": "Change request rejected successfully",
          }
      except requests.exceptions.RequestException as e:
          logger.error(f"Error rejecting change: {e}")
          return {
              "success": False,
              "message": f"Error rejecting change: {str(e)}",
          } 

• src/servicenow_mcp/tools/change_tools.py:99-105 (schema)

  Pydantic BaseModel defining the input schema for the reject_change tool, including required change_id and rejection_reason, optional approver_id.

  class RejectChangeParams(BaseModel):
      """Parameters for rejecting a change request."""
  
      change_id: str = Field(..., description="Change request ID or sys_id")
      approver_id: Optional[str] = Field(None, description="ID of the approver")
      rejection_reason: str = Field(..., description="Reason for rejection")

• src/servicenow_mcp/utils/tool_utils.py:528-534 (registration)

  Tool registration in the central tool_definitions dictionary used by the MCP server, associating the tool name with its handler function (aliased), params schema, return type hint, description, and serialization method.

  "reject_change": (
      reject_change_tool,
      RejectChangeParams,
      str,
      "Reject a change request",
      "str",  # Tool returns simple message
  ),