Streaming Not Working When Proxied

Issue

Streaming with the AI SDK doesn't work in local development environment, or deployed in some proxy environments. Instead of streaming, only the full response is returned after a while.

Cause

The causes of this issue are caused by the proxy middleware.

If the middleware is configured to compress the response, it will cause the streaming to fail.

Solution

You can try the following, the solution only affects the streaming API:

• add 'Content-Encoding': 'none' headers

  tsxCopy

  return result.toUIMessageStreamResponse({
    headers: {
      'Content-Encoding': 'none',
    },
  });