ai-python-subagents

# ai-python-subagents Use a subagent tool when the parent model should choose when to call another agent. ```python @ai.tool async def research(topic: str) -> ai.SubAgentTool: child = ai.Agent(tools=[lookup]) messages = [ ai.system_message("Research briefly."), ai.user_message(topic), ] async with child.run(model, messages) as stream: async for event in stream: yield event ``` The parent model sees the child agent's final assistant text as the tool result. The caller sees child events as `ai.events.PartialToolCallResult`. Render nested output from `event.value`: ```python if isinstance(event, ai.events.PartialToolCallResult): if isinstance(event.value, ai.events.TextDelta): print(event.value.chunk, end="", flush=True) ``` Do not append child messages to the parent history yourself. The tool result stores the child transcript as a `MessageBundle`. For `MessageBundle`, preliminary output, and streaming tool details, use `ai-python-streaming-tools`.