fix repeated api call bug
diff --git a/metagpt/provider/openai_api.py b/metagpt/provider/openai_api.py
index 8f3b71c42..e99707ab9 100644
--- a/metagpt/provider/openai_api.py
+++ b/metagpt/provider/openai_api.py
@@ -142,7 +142,7 @@ async def acompletion(self, messages: list[dict], timeout=3) -> ChatCompletion:
     async def acompletion_text(self, messages: list[dict], stream=False, timeout=3) -> str:
         """when streaming, print each token in place."""
         if stream:
-            await self._achat_completion_stream(messages, timeout=timeout)
+            return await self._achat_completion_stream(messages, timeout=timeout)
 
         rsp = await self._achat_completion(messages, timeout=timeout)
         return self.get_choice_text(rsp)
