---
type: email
from: Chris <notifications@github.com>
subject: [openai/openai-agents-python] Streaming runner doesn't emit complete

 arguments for tool call events (Issue #1651)
received: 2026-03-06 07:21:14
date_header: Wed, 03 Sep 2025 11:04:44 -0700
priority: normal
status: awaiting_approval
uid: 29422
---

## Email Content

**From:** Chris <notifications@github.com>
**Subject:** [openai/openai-agents-python] Streaming runner doesn't emit complete

 arguments for tool call events (Issue #1651)
**Date:** Wed, 03 Sep 2025 11:04:44 -0700

### Body (preview)

chcaru created an issue (openai/openai-agents-python#1651)



### Please read this first



- **Have you read the docs?** ✅

- **Have you searched for related issues?** ✅



### Describe the bug



[Fix: Emit tool_called events immediately in streaming runs](https://github.com/openai/openai-agents-python/pull/1300) regressed presence of `arguments` for tool calls in *any* `run_item_stream_event`s.



Previously, `arguments` were present on the tool call when `event.type == 'run_item_stream_event' and event.item.type == "tool_call_item"`. The above PR emits the tool call immediately during streaming (as the change intended), before `arguments` are accumulated from the stream. This alone could be fine, if there were an alternative method to acquire completed tool call arguments on completion, but there isn't.



<img width="1587" height="104" alt="Image" src="https://github.com/user-attachments/assets/2720fabb-137c-415e-90e6-a75904a8bf0b" />



It is possible to accumulate the tool call args using raw events: `event=RawResponsesStreamEvent(data=ResponseFunctionCallArgumentsDeltaEvent(delta` stream, but this is cumbersome and imo breaks the non-raw higher-level `run_item_stream_event`s API.



Additionally, it seems like maintainers didn't expect this to happen based on the comment thread for the change:

- https://github.com/openai/openai-agents-python/pull/1300#issuecomment-3178058881

- and was left unchecked per https://github.com/openai/openai-agents-python/pull/1300#issuecomment-3218563239



### Debug information

- Agents SDK version: `v0.2.10`

- Python version: `3.10.12`



### Repro steps



Setup an Agent with a single tool that has args. Using the streaming runner and observe the events noted above and their properties.



### Expected behavior



When using the streaming runner, have some way in the high-level `run_item_stream_event` API to acquire the complete `arguments` payload for a tool call.



#### Proposed fix, some variant of:



My suggestion wo

---

## Suggested Actions
- [ ] Reply
- [ ] Archive
- [ ] Escalate
