From f8791104cbe26d66f3ddc1c61f0cb6961ae063bb Mon Sep 17 00:00:00 2001
From: goulustis <cnimaiv@gmail.com>
Date: Fri, 30 Jan 2026 11:18:52 +0800
Subject: [PATCH] sync returns non-string when streaming

---
 lang_agent/base.py | 36 ++++++++++++++++++++++++++++++------
 1 file changed, 30 insertions(+), 6 deletions(-)

diff --git a/lang_agent/base.py b/lang_agent/base.py
index 1a2fcdc..27a8026 100644
--- a/lang_agent/base.py
+++ b/lang_agent/base.py
@@ -37,14 +37,33 @@ class GraphBase(ABC):
     
     def _stream_result(self, *nargs, **kwargs):
 
+        # def text_iterator():
+        #     for chunk, metadata in self.workflow.stream({"inp": nargs}, 
+        #                                                 stream_mode="messages", 
+        #                                                 subgraphs=True,
+        #                                                 **kwargs):
+        #         if isinstance(metadata, tuple):
+        #             chunk, metadata = metadata
+
+        #         tags = metadata.get("tags")
+        #         if not (tags in self.streamable_tags):
+        #             continue
+
+        #         if isinstance(chunk, (BaseMessageChunk, BaseMessage)) and getattr(chunk, "content", None):
+        #             yield chunk.content
+
         def text_iterator():
-            for chunk, metadata in self.workflow.stream({"inp": nargs}, 
-                                                        stream_mode="messages", 
+            for _, mode, out in self.workflow.stream({"inp": nargs}, 
+                                                        stream_mode=["messages", "values"], 
                                                         subgraphs=True,
                                                         **kwargs):
-                if isinstance(metadata, tuple):
-                    chunk, metadata = metadata
+                if mode == "values":
+                    val = out.get("messages")
+                    if val is not None:
+                        yield val
+                    continue
 
+                chunk, metadata = out
                 tags = metadata.get("tags")
                 if not (tags in self.streamable_tags):
                     continue
@@ -55,7 +74,8 @@ class GraphBase(ABC):
         text_releaser = TextReleaser(*self.textreleaser_delay_keys)
         logger.info("streaming output")
         for chunk in text_releaser.release(text_iterator()):
-            print(f"\033[92m{chunk}\033[0m", end="", flush=True)
+            if isinstance(chunk, str):
+                print(f"\033[92m{chunk}\033[0m", end="", flush=True)
             yield chunk
     
     # NOTE: DEFAULT IMPLEMENTATION; Overide to support your class
@@ -138,6 +158,10 @@ class GraphBase(ABC):
 
         assert len(kwargs) == 0, "due to inp assumptions"
     
+    def _get_inp_msgs(self, state:State):
+        msgs = state["inp"][0]["messages"]
+        return [e for e in msgs if not isinstance(e, SystemMessage)]
+    
     def _agent_call_template(self, system_prompt:str,
                                   model:CompiledStateGraph, 
                                   state:State,
@@ -149,7 +173,7 @@ class GraphBase(ABC):
         
         messages = [
             SystemMessage(system_prompt),
-            *state["inp"][0]["messages"][1:]
+            *self._get_inp_msgs(state)
         ]
 
         if human_msg is not None: