Method rewind_async

src/google/adk/runners.py:1136–1185

Rewinds the session to before the specified invocation.

(
      self,
      *,
      user_id: str,
      session_id: str,
      rewind_before_invocation_id: str,
      run_config: Optional[RunConfig] = None,
  )

        yield event

  async def rewind_async(
      self,
      *,
      user_id: str,
      session_id: str,
      rewind_before_invocation_id: str,
      run_config: Optional[RunConfig] = None,
  ) -> None:
    """Rewinds the session to before the specified invocation."""
    run_config = run_config or RunConfig()
    session = await self._get_or_create_session(
        user_id=user_id,
        session_id=session_id,
        get_session_config=run_config.get_session_config,
    )
    rewind_event_index = -1
    for i, event in enumerate(session.events):
      if event.invocation_id == rewind_before_invocation_id:
        rewind_event_index = i
        break

    if rewind_event_index == -1:
      raise ValueError(
          f'Invocation ID not found: {rewind_before_invocation_id}'
      )

    # Compute state delta to reverse changes
    state_delta = await self._compute_state_delta_for_rewind(
        session, rewind_event_index
    )

    # Compute artifact delta to reverse changes
    artifact_delta = await self._compute_artifact_delta_for_rewind(
        session, rewind_event_index
    )

    # Create rewind event
    rewind_event = Event(
        invocation_id=new_invocation_context_id(),
        author='user',
        actions=EventActions(
            rewind_before_invocation_id=rewind_before_invocation_id,
            state_delta=state_delta,
            artifact_delta=artifact_delta,
        ),
    )

    logger.info('Rewinding session to invocation: %s', rewind_event)

    await self.session_service.append_event(session=session, event=rewind_event)

  async def _compute_state_delta_for_rewind(
      self, session: Session, rewind_event_index: int