diff --git a/lang_agent/graphs/routing.py b/lang_agent/graphs/routing.py
index 7b24b8c..8c5a55d 100644
--- a/lang_agent/graphs/routing.py
+++ b/lang_agent/graphs/routing.py
@@ -2,6 +2,7 @@ from dataclasses import dataclass, field, is_dataclass
 from typing import Type, TypedDict, Literal, Dict, List, Tuple
 import tyro
 from pydantic import BaseModel, Field
+from loguru import logger
 
 from lang_agent.config import KeyConfig
 from lang_agent.tool_manager import ToolManager, ToolManagerConfig
@@ -43,6 +44,7 @@ class State(TypedDict):
     inp: Tuple[Dict[str, List[SystemMessage | HumanMessage]], 
                Dict[str, Dict[str, str|int]]]
     output: str
+    tool_output: str
     decision:str
 
 
@@ -61,7 +63,8 @@ class RoutingGraph(GraphBase):
 
         if as_stream:
             for step in self.workflow.stream({"inp": nargs}, stream_mode="values", **kwargs):
-                step["messages"][-1].pretty_print()
+                if "messages" in step:
+                    step["messages"][-1].pretty_print()
             state = step
         else:
             state = self.workflow.invoke({"inp": nargs})
@@ -85,7 +88,7 @@ class RoutingGraph(GraphBase):
         decision:Route = self.router.invoke(
             [
                 SystemMessage(
-                    content="Route to chat or order based on the need of the user"
+                    content="Return a JSON object with 'step'.the value should be one of 'chat' or 'order' based on the user input"
                 ),
                 self._get_human_msg(state)
             ]
@@ -95,8 +98,10 @@ class RoutingGraph(GraphBase):
 
 
     def _get_human_msg(self, state: State)->HumanMessage:
+        """
+        get user message of current invocation
+        """
         msgs = state["inp"][0]["messages"]
-        assert len(msgs) == 2, "Expect 1 systemMessage, 1 HumanMessage"
         candidate_hum_msg = msgs[1]
         assert isinstance(candidate_hum_msg, HumanMessage), "not a human message"
 
@@ -104,10 +109,11 @@ class RoutingGraph(GraphBase):
     
 
     def _route_decision(self, state:State):
-        if state.decision == "chat":
-            return "_chat_model_call"
+        logger.info(f"decision:{state["decision"]}")
+        if state["decision"] == "chat":
+            return "chat"
         else:
-            return "_tool_model_call"
+            return "tool"
 
 
     def _chat_model_call(self, state:State):
@@ -116,11 +122,11 @@ class RoutingGraph(GraphBase):
 
 
     def _tool_model_call(self, state:State):
-        inp = [
+        inp = {"messages":[
             SystemMessage(
                 "You must use tool to complete the possible task"
             ),self._get_human_msg(state)
-        ], state["inp"][1]
+        ]}, state["inp"][1]
 
         out = self.tool_model.invoke(*inp)
         return {"output": out["messages"][-1].content}
@@ -143,8 +149,9 @@ class RoutingGraph(GraphBase):
                 "tool": "tool_model_call"
             }
         )
-        builder.add_edge("chat_model_call", END)
         builder.add_edge("tool_model_call", END)
+        builder.add_edge("tool_model_call", "chat_model_call")
+        builder.add_edge("chat_model_call", END)
 
         workflow = builder.compile()