diff --git a/lang_agent/graphs/tool_nodes.py b/lang_agent/graphs/tool_nodes.py
index fa4487f..06b8907 100644
--- a/lang_agent/graphs/tool_nodes.py
+++ b/lang_agent/graphs/tool_nodes.py
@@ -1,17 +1,16 @@
 from dataclasses import dataclass, field, is_dataclass
 from typing import Type, TypedDict, Literal, Dict, List, Tuple
 import tyro
-import os
 import os.path as osp
 
 
 from lang_agent.config import InstantiateConfig, KeyConfig
 from lang_agent.tool_manager import ToolManager
-from lang_agent.base import ToolNodeBase
-from lang_agent.graphs.graph_states import State
+from lang_agent.base import GraphBase
+from lang_agent.graphs.graph_states import State, ChattyToolState
 
 from langchain_core.language_models import BaseChatModel
-from langchain_core.messages import SystemMessage
+from langchain_core.messages import SystemMessage, HumanMessage, AIMessage
 from langchain.agents import create_agent
 from langchain.chat_models import init_chat_model
 
@@ -26,7 +25,7 @@ class ToolNodeConfig(InstantiateConfig):
     tool_prompt_f:str = osp.join(osp.dirname(osp.dirname(osp.dirname(__file__))), "configs", "route_sys_prompts", "tool_prompt.txt")
 
 
-class ToolNode(ToolNodeBase):
+class ToolNode(GraphBase):
     def __init__(self, config: ToolNodeConfig, 
                        tool_manager:ToolManager,
                        llm:BaseChatModel,
@@ -43,7 +42,7 @@ class ToolNode(ToolNodeBase):
         with open(self.config.tool_prompt_f, "r") as f:
             self.sys_prompt = f.read()
 
-    def tool_node_call(self, state:State):
+    def invoke(self, state:State):
         inp = {"messages":[
             SystemMessage(
                 self.sys_prompt
@@ -71,7 +70,7 @@ class ChattyToolNodeConfig(KeyConfig, ToolNodeConfig):
     chatty_sys_prompt_f:str = osp.join(osp.dirname(osp.dirname(osp.dirname(__file__))), "configs", "route_sys_prompts", "chatty_prompt.txt")
 
 
-class ChattyToolNode:
+class ChattyToolNode(GraphBase):
     def __init__(self, config:ChattyToolNodeConfig, 
                        tool_manager:ToolManager,
                        llm:BaseChatModel,
@@ -102,8 +101,15 @@ class ChattyToolNode:
         with open(self.config.tool_prompt_f, "r") as f:
             self.tool_sys_prompt = f.read()
 
+    def invoke(self, state:State):
+        inp = {"inp": state["inp"]}
+        out = self.workflow.invoke(inp)
+        chat_msgs = out.get("chatty_message")
+        tool_msgs = out.get("tool_message")
+
+        return {"messages": state["messages"] + chat_msgs + tool_msgs}
     
-    def _tool_node_call(self, state:State):
+    def _tool_node_call(self, state:ChattyToolState):
         inp = {"messages":[
             SystemMessage(
                 self.tool_sys_prompt
@@ -113,11 +119,10 @@ class ChattyToolNode:
 
         out = self.tool_agent.invoke(*inp)
 
-
-        return {"subgraph_states":{"tool_message": out}}
+        return {"tool_messages": out}
 
     
-    def _chat_node_call(self, state:State):
+    def _chat_node_call(self, state:ChattyToolState):
         outs = []
 
         while not self.tool_done:
@@ -129,18 +134,20 @@ class ChattyToolNode:
                     ]}, state["inp"][1]
             outs.append(self.chatty_agent.invoke(*inp))
         
-        return {"subgraph_states":{"chatty_message": outs}}
+        return {"chatty_message": outs}
 
 
-    def _handoff_node(self, state:State):
-        chat_msgs = state.get("subgraph_states").get("chatty_message")
-        tool_msgs = state.get("subgraph_states").get("tool_message")
+    def _handoff_node(self, state:ChattyToolState):
+        # NOTE: this exist to have both results
+        # chat_msgs = state.get("chatty_message")
+        # tool_msgs = state.get("tool_message")
 
-        return {"messages": state["messages"] + chat_msgs + tool_msgs}
+        # return {"messages": chat_msgs + tool_msgs}
+        return {}
 
 
     def build_graph(self):
-        builder = StateGraph(State)
+        builder = StateGraph(ChattyToolState)
         builder.add_node("chatty_tool_call", self._tool_node_call)
         builder.add_node("chatty_chat_call", self._chat_node_call)
         builder.add_node("chatty_handoff_node", self._handoff_node)