[pcbeingused333]

💡 Motivation and Context

accumulate_openai_tool_calls skipped every tool call delta whose index is None. Some OpenAI-compatible providers send streamed tool calls without an index, so those calls never reached $ai_output for the Chat Completions streaming wrappers (sync and async share this function).

A delta without an index is now matched by its id when one is present and already known. Otherwise a delta with a new id or a function name opens a new call, and a delta with neither id nor function name appends its arguments to the latest call. Deltas with an index take the same path as before.

💚 How did you test it?

• Four new tests in posthog/test/ai/openai/test_openai_converter.py: two index-less calls sent whole through _ChatCompletionsStreamState, argument fragments joined onto the latest call, two whole calls with a name and neither id nor index giving two calls, and a guard that indexed deltas behave as before. All but the guard fail on main (the calls are dropped).
• posthog/test/ai: 1069 passed, 15 skipped. ruff check reports the same 54 findings as on main; ruff format is clean on the changed lines.
• The chunks in the tests are synthetic; no real index-less provider stream was recorded and nothing ran against a live API.

📝 Checklist

• I reviewed the submitted code.
• I added tests to verify the changes.
• I updated the docs if needed. (n/a)
• No breaking change or entry added to the changelog.

If releasing new changes

• Ran sampo add to generate a changeset file (added .sampo/changesets/openai-stream-tool-calls-without-index.md in the same format)

🤖 Agent context

Autonomy: Fully autonomous

• Written with Claude Code (Claude Sonnet 5.5): the fix, the tests and this description.
• When the index is missing, matching by id and then by function name is a heuristic for providers that send each call whole; a provider that interleaves several index-less calls with partial arguments and no ids cannot be told apart, and a continuation fragment that repeats the function name would open a new call.

🤖 Generated with Claude Code

[marandaneto]

Automated advisory code review.

[pcbeingused333]

Thanks, good catch. Fixed in 8fed35a: calls without an index now get keys of their own (no-index-N) instead of max + 1, so they can no longer take an index the provider sends later, and an argument-only delta continues the most recently added call. Added your scenario as test_indexless_call_does_not_corrupt_later_indexed_call (it fails on the previous head with {}{} and passes now) plus a test that the calls keep their arrival order. a0f8122 widens the accumulator's key type in _streaming.py to match.

[marandaneto]

Automated advisory code review.

[marandaneto]

thanks @pcbeingused333