diff --git a/lang_agent/pipeline.py b/lang_agent/pipeline.py
index 0128479..9414c8c 100644
--- a/lang_agent/pipeline.py
+++ b/lang_agent/pipeline.py
@@ -118,9 +118,7 @@ class Pipeline:
 
         # If streaming, yield chunks from the generator
         if kwargs.get("as_stream"):
-            for chunk in out:
-                yield chunk
-            return
+            return self._stream_res(out)
 
         # Non-streaming path
         if kwargs.get("as_raw"):
@@ -165,6 +163,9 @@ class Pipeline:
     def get_ws_url(self):
         return f"ws://{self.config.host}:{self.config.port}"
     
+    def _stream_res(self, out:list):
+        for chunk in out:
+            yield chunk
 
     def chat(self, inp:str, as_stream:bool=False, as_raw:bool=False, thread_id:int = None):
         # NOTE: this prompt will be overwritten by 'configs/route_sys_prompts/chat_prompt.txt' for route graph
@@ -178,7 +179,6 @@ class Pipeline:
 
         if as_stream:
             # Yield chunks from the generator
-            for chunk in out:
-                yield chunk
+            return self._stream_res(out)
         else:
             return out
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