use tool node

backend/app/graphs/new_agent.py

@@ -1,4 +1,4 @@
-from typing import Annotated, Any, Dict, TypedDict, cast
+from typing import Annotated, Any, Dict, TypedDict
 
 from langchain_core.messages import (
     AIMessage,
@@ -12,7 +12,7 @@
 from langgraph.graph import END, StateGraph
 from langgraph.graph.message import add_messages
 from langgraph.managed.few_shot import FewShotExamples
-from langgraph.prebuilt import ToolExecutor, ToolInvocation
+from langgraph.prebuilt import ToolNode
 
 from app.llms import LLMType, get_llm
 from app.message_types import LiberalToolMessage
@@ -148,7 +148,6 @@ def should_continue(state):
 
 # Define the function to execute tools
 async def call_tool(state, config):
-    messages = state["messages"]
     _config = config["configurable"]
     tools = get_tools(
         _config.get("type==agent/tools"),
@@ -157,33 +156,8 @@ async def call_tool(state, config):
         _config.get("type==agent/retrieval_description"),
     )
 
-    tool_executor = ToolExecutor(tools)
-    actions: list[ToolInvocation] = []
-    # Based on the continue condition
-    # we know the last message involves a function call
-    last_message = cast(AIMessage, messages[-1])
-    for tool_call in last_message.tool_calls:
-        # We construct a ToolInvocation from the function_call
-        actions.append(
-            ToolInvocation(
-                tool=tool_call["name"],
-                tool_input=tool_call["args"],
-            )
-        )
-    # We call the tool_executor and get back a response
-    responses = await tool_executor.abatch(actions)
-    # We use the response to create a ToolMessage
-    tool_messages = [
-        LiberalToolMessage(
-            tool_call_id=tool_call["id"],
-            name=tool_call["name"],
-            content=response,
-        )
-        for tool_call, response in zip(last_message.tool_calls, responses)
-    ]
-
-    # graph state is a dict, so return type must be dict
-    return {"messages": tool_messages}
+    tool_node = ToolNode(tools)
+    return await tool_node.ainvoke(state)
 
 
 workflow = StateGraph(BaseState)