IndexError: list index out of range when using async stream with a tool

[off6atomic]

Description

Run the following code:

import asyncio

from dotenv import load_dotenv
from mirascope.core import BaseMessageParam, openai

load_dotenv()


def hello_world_tool():
    print("hello world")


@openai.call("gpt-4o-mini", stream=True, tools=[hello_world_tool]) 
async def recommend_book(genre: str) -> list[BaseMessageParam]:
    return [BaseMessageParam(role="user", content=f"Recommend a {genre} book")]


async def main():
    stream = await recommend_book("fantasy")
    async for chunk, tool in stream:
        if tool:
            tool.call()
        else:
            print(chunk.content, end="", flush=True)


if __name__ == "__main__":
    asyncio.run(main())

Get the following output:

I recommend "The Name of the Wind" by Patrick Rothfuss. It's the first book in the "Kingkiller Chronicle" series and follows the story of Kvothe, a gifted young man who grows up to be a legendary figure. The book is known for its beautiful prose, rich world-building, and deep character development. If you enjoy tales of magic, adventure, and music, this book is a fantastic choice!Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/runpy.py", line 196, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/runpy.py", line 86, in _run_code
    exec(code, run_globals)
  File "/Users/chanchana/Documents/catalyst-ai/src/v2/scripts/test_mirascope.py", line 28, in <module>
    asyncio.run(main())
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/asyncio/runners.py", line 44, in run
    return loop.run_until_complete(main)
  File "/Library/Frameworks/Python.framework/Versions/3.10/lib/python3.10/asyncio/base_events.py", line 649, in run_until_complete
    return future.result()
  File "/Users/chanchana/Documents/catalyst-ai/src/v2/scripts/test_mirascope.py", line 20, in main
    async for chunk, tool in stream:
  File "/Users/chanchana/Documents/catalyst-ai/.venv/lib/python3.10/site-packages/mirascope/core/openai/stream.py", line 93, in generator
    async for chunk, tool in aiter:
  File "/Users/chanchana/Documents/catalyst-ai/.venv/lib/python3.10/site-packages/mirascope/core/base/stream.py", line 171, in generator
    async for chunk, tool in self.stream:
  File "/Users/chanchana/Documents/catalyst-ai/.venv/lib/python3.10/site-packages/mirascope/core/base/stream.py", line 381, in generator
    async for chunk, tool in handle_stream_async(
  File "/Users/chanchana/Documents/catalyst-ai/.venv/lib/python3.10/site-packages/mirascope/core/openai/_utils/_handle_stream.py", line 121, in handle_stream_async
    if not tool_types or not chunk.choices[0].delta.tool_calls:
IndexError: list index out of range

If you remove the hello_world_tool from the tools argument the code would run without error.

How can I work around this?

Python, Mirascope & OS Versions, related packages (not required)

openai==1.59.7
pydantic==2.10.5
pydantic-core==2.27.2
mirascope==1.15.1

[off6atomic]

@willbakst This one is a serious bug I think. Because it disallow me from streaming tools and tokens asynchronously (for FastAPI endpoint). In v0, I was able to do it.

[willbakst]

Looks like the fix for this was already implemented in the sync case but missed for the async case.

Fix is released in v1.16.1!