TypeError: int() argument must be a string ... not 'NoneType' in _accumulate_stream_items when streaming tool calls from Gemini

[GDegrove]

Bug Description

When streaming chat completions with tool calls from Google's OpenAI-compatible Gemini API, the instrumentor crashes with an unhandled TypeError that propagates up and kills the response stream:

File "opentelemetry/instrumentation/openai/shared/chat_wrappers.py", line 1176, in _accumulate_stream_items
    i = int(tool_call["index"])
TypeError: int() argument must be a string, a bytes-like object or a real number, not 'NoneType'

Root Cause

Gemini's OpenAI-compatible API returns ndex: null on streaming tool call delta chunks. _accumulate_stream_items unconditionally calls int(tool_call["index"]) with no guard for None.

# chat_wrappers.py line 1176 — crashes when index is None
i = int(tool_call["index"])

Why Non-Streaming Is Not Affected
Two reasons:

1. _handle_response is decorated with @dont_throw — any exception is silently caught and logged
   _set_completions iterates tool calls using enumerate() and never accesses tool_call["index"]

For streaming, _process_item has no @dont_throw decorator, so the TypeError propagates all the way up through the Starlette response stream and crashes the request.

Suggested Fix
One-line fix on line 1176:

# Before
i = int(tool_call["index"])

# After
i = int(tool_call["index"] or 0)

Or, for consistency with the non-streaming code path, add @dont_throw to _process_item.

Reproduction

from openai import AsyncOpenAI
from opentelemetry.instrumentation.openai import OpenAIInstrumentor

OpenAIInstrumentor().instrument()

client = AsyncOpenAI(
    api_key="<GEMINI_API_KEY>",
    base_url="https://generativelanguage.googleapis.com/v1beta/openai/",
)

stream = await client.chat.completions.create(
    model="gemini-2.5-flash",
    stream=True,
    messages=[{"role": "user", "content": "What's the weather in Paris?"}],
    tools=[{
        "type": "function",
        "function": {
            "name": "get_weather",
            "description": "Get the current weather",
            "parameters": {
                "type": "object",
                "properties": {"location": {"type": "string"}},
                "required": ["location"],
            },
        },
    }],
)

async for chunk in stream:  # ← crashes here
    print(chunk)

Environment

• opentelemetry-instrumentation-openai==0.52.3 (latest)
• OpenAI Python SDK v1
• Provider: Google Gemini via OpenAI-compatible endpoint (generativelanguage.googleapis.com/v1beta/openai/)
• Python 3.14