Bedrock Runtime > Structures > MessageStopEvent MessageStopEvent¶ Structure Class¶ MessageStopEvent dataclass ¶ The stop event for a message. Attributes¶ additional_model_response_fields class-attribute instance-attribute ¶ additional_model_response_fields: Document | None = None The additional model response fields. stop_reason instance-attribute ¶ stop_reason: str The reason why the model stopped generating output.