如何实现一个实时转发 Stream 流的接口

想写一个实时转发 Stream 流内容的接口，不怎么懂 stream 流相关的知识

之前的接口是

async def index(path: str, request: Request): data = await request.json() resp = c.send_request(path, data) headers = dict(resp.headers) async def generate(): for chunk in resp.iter_lines(): if chunk: yield chunk + b'\n\n' return StreamingResponse(generate(), headers=headers) 

问题是，这个会等接受完全部的 Stream 流信息，才会转发，想实现的效果是实时转发 stream 流信息，具体一点就是，接收到一行或者指定大小的信息块，就转发出去。

想法是将 resp = c.send_request(path, data)这块改造成异步的，然后实时转发。

目前的代码是

async def index(path: str, request: Request): data = await request.json() async with httpx.AsyncClient() as client: async with client.stream('POST', path, json=data) as response: resp_headers = dict(response.headers) async def generate(): async for line in response.aiter_lines(): if line: yield line.encode('utf-8') + b'\n\n' return StreamingResponse(generate(), headers=resp_headers) 

但是会报：

httpx.StreamClosed: Attempted to read or stream content, but the stream has been closed.

不知道怎么改，求赐教