From 7ae3ae611025fc8f211c5eac18598494b69200c7 Mon Sep 17 00:00:00 2001
From: Shreya Sevelar <116109558+ShreyaSev@users.noreply.github.com>
Date: Tue, 8 Sep 2026 22:29:35 +0530
Subject: [PATCH] Update _stream.pyfix: handle Responses API event shape in
 OpenAI stream

The OpenAI streamer assumed Chat Completions chunks (chunk.choices),
but adalflow returns Responses API events, raising AttributeError on
the first iteration.

Fixes #585"
---
 api/chat/_stream.py | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/api/chat/_stream.py b/api/chat/_stream.py
index dcb7f52ab..921e8b2c2 100644
--- a/api/chat/_stream.py
+++ b/api/chat/_stream.py
@@ -165,13 +165,21 @@ async def respond_stream(self, prompt: str) -> AsyncIterator[str]:
         )
 
         async for chunk in response:
+            # Responses API event shape
+            if getattr(chunk, "type", "") == "response.output_text.delta":
+                delta = getattr(chunk, "delta", None)
+                if delta:
+                    yield delta
+                continue
+
+            # Chat Completions chunk shape
+            choices = getattr(chunk, "choices", None)
             if (
-                chunk.choices
-                and chunk.choices[0].delta is not None
-                and chunk.choices[0].delta.content is not None
+                choices
+                and choices[0].delta is not None
+                and choices[0].delta.content is not None
             ):
-                yield chunk.choices[0].delta.content
-
+                yield choices[0].delta.content
 
 class OpenAIChatStreamer(_OpenAICompatStreamer):
     provider = "openai"