responses.parse returns an error in streaming mode

[futuremojo]

Confirm this is an issue with the Python library and not an underlying OpenAI API

• This is an issue with the Python library

Describe the bug

When I use a Pydantic model in response.parse, it works fine in synchronous mode. But in asynchronous mode, I get an error.

See test code below.

To Reproduce

The code to reproduce the issue is below.

When the code is run, the synchronous version of response.parse returns a correct response. The asynchronous version results in this error:

AttributeError                            Traceback (most recent call last)
File ~/projects/pdf_summarizer/.venv/lib/python3.12/site-packages/openai/lib/_parsing/_responses.py:62, in parse_response(text_format, input_tools, response)
     59 solved_t = solve_response_format_t(text_format)
     60 output_list: List[ParsedResponseOutputItem[TextFormatT]] = []
---> 62 for output in response.output:
     63     if output.type == "message":
     64         content_list: List[ParsedContent[TextFormatT]] = []

AttributeError: 'str' object has no attribute 'output'

Code snippets

import json
from typing import List

import openai
from pydantic import BaseModel
import pytest


class CalendarEvent(BaseModel):
    name: str
    date: str
    participants: List[str]

def test_response_parse_sync():
    client = openai.OpenAI()

    response = client.responses.parse(
        model="gpt-4o-2024-08-06",
        input=[
            {"role": "system", "content": "Extract the event information."},
            {"role": "user", "content": "Alice and Bob are going to a science fair on Friday."},
        ],
        text_format=CalendarEvent,
    )
    return response

async def test_response_parse_async():
    client = openai.AsyncOpenAI()

    stream = await client.responses.parse(
        model="gpt-4o-2024-08-06",
        input=[
            {"role": "system", "content": "Extract the event information."},
            {"role": "user", "content": "Alice and Bob are going to a science fair on Friday."},
        ],
        text_format=CalendarEvent,
        stream=True,
    )
    async for event in stream:
        print(event)


# Returns a response conforming to the Pydantic model.
print(test_response_parse_sync())

# Errors out.
await test_response_parse_async()

OS

macOS

Python version

Python v3.12

Library version

OpenAI v1.73.0