Update app.py

app.py

@@ -8,7 +8,7 @@ from langchain_core.messages import AnyMessage
 from langchain_huggingface import HuggingFaceEndpoint, ChatHuggingFace
 from langgraph.graph.message import add_messages
 from langchain_hyperbrowser import HyperbrowserBrowserUseTool
-from langgraph.graph import START, StateGraph
+from langgraph.graph import START, StateGraph, MessagesState
 from langgraph.prebuilt import ToolNode, tools_condition
 from langchain_core.messages import HumanMessage, SystemMessage
 from langchain_community.tools import DuckDuckGoSearchResults
@@ -23,14 +23,14 @@ llm_with_tools = chat.bind_tools(tools)
 class State(TypedDict):
     messages = Annotated[list[AnyMessage], add_messages]
 
-def assistant(state:State):
+def assistant(state:MessagesState):
     system_message = SystemMessage(content="You are a helpful assistant. Your job is to answer the questions asked of you as accurately as possible. You have access to search and browser tools, which you may use when needed to answer a question.")
     print(state["messages"])
     return {
         "messages": [llm_with_tools.invoke([system_message] + state["messages"])]
     }
 
-workflow = StateGraph(State)
+workflow = StateGraph(state_schema=MessagesState)
 workflow.add_node("assistant", assistant)
 workflow.add_node("tools", ToolNode(tools))
 workflow.add_edge(START, "assistant")