类class agentscope.app.middleware

StateChangeMiddleware

class StateChangeMiddleware(MiddlewareBase)

源码Source agentscope/app/middleware/_state_change_middleware.py:42–196

状态变更中间件，在智能体执行流程中提供横切扩展。位于 agentscope.app.middleware 包，继承自 MiddlewareBase。核心成员包括 on_reply、on_acting。

Detect state / team changes after each tool call and push notifications to the session event stream. Declared in agentscope.app.middleware. Extends MiddlewareBase.

构造器摘要Constructor Summary

构造器Constructor	说明Description
`def __init__(message_bus:` `MessageBus, session_id: str) -> None`	初始化 `StateChangeMiddleware` 实例。 Initialise the middleware.

方法摘要Method Summary

方法Method	说明Description
`async def on_reply(agent: Any, input_kwargs: dict, next_handler: Callable[..., AsyncGenerator]) -> AsyncGenerator`async	拦截并扩展回复流程。 Wrap the whole reply turn to catch state changes that happen outside the ``on_acting`` tool-execution window.
`async def on_acting(agent: Any, input_kwargs: dict, next_handler: Callable[..., AsyncGenerator]) -> AsyncGenerator`async	拦截并扩展工具执行阶段。 Wrap tool execution: snapshot state hash before, compare after, and push notifications if anything changed.

构造器详情Constructor Detail

StateChangeMiddleware

def __init__(message_bus: MessageBus, session_id: str) -> None

初始化 StateChangeMiddleware 实例。

Initialise the middleware.

参数Parameters

名称Name	类型Type	说明Description
`message_bus`	MessageBus	消息总线（类型 `MessageBus`）。Application message bus.
`session_id`	str	会话标识到发布事件用于。The session id to publish events for.

源码Source agentscope/app/middleware/_state_change_middleware.py:54–68

方法详情Method Detail

on_reply

async def on_reply(agent: Any, input_kwargs: dict, next_handler: Callable[..., AsyncGenerator]) -> AsyncGenerator

async

拦截并扩展回复流程。

Permission rules added while handling a UserConfirmResultEvent (the user's "always allow" choice) mutate permission_context in _handle_incoming_event — which runs at the start of the reply turn, before the confirmed tool's on_acting snapshot is taken.

参数Parameters

名称Name	类型Type	说明Description
`agent`	Any	智能体（类型 `Any`）。The executing agent.
`input_kwargs`	dict	输入关键字参数（类型 `dict`）。The reply inputs (new message(s) or a resumption event).
`next_handler`	Callable[..., AsyncGenerator]	下一个处理器（类型 `Callable[..., AsyncGenerator]`）。The downstream middleware or core reply logic.

返回Returns AsyncGenerator

返回AsyncGenerator。`AgentEvent | Msg` — unchanged from downstream.

源码Source agentscope/app/middleware/_state_change_middleware.py:117–152

on_acting

async def on_acting(agent: Any, input_kwargs: dict, next_handler: Callable[..., AsyncGenerator]) -> AsyncGenerator

async

拦截并扩展工具执行阶段。

Wrap tool execution: snapshot state hash before, compare after, and push notifications if anything changed.

参数Parameters

名称Name	类型Type	说明Description
`agent`	Any	智能体（类型 `Any`）。The executing agent.
`input_kwargs`	dict	输入关键字参数（类型 `dict`）。Contains `tool_call` (`ToolCallBlock`).
`next_handler`	Callable[..., AsyncGenerator]	下一个处理器（类型 `Callable[..., AsyncGenerator]`）。The downstream middleware or core acting logic.

返回Returns AsyncGenerator

返回AsyncGenerator。`ToolChunk | ToolResponse` — unchanged from downstream.

源码Source agentscope/app/middleware/_state_change_middleware.py:154–196

继承成员Inherited Members

继承自Inherited from MiddlewareBase

is_implemented, on_reasoning, on_check_permission, on_model_call, on_compress_context, on_system_prompt, list_tools, get_middleware_key