Memory is not persisting in langGraph. am i doing something wrong ? from dotenv import load_dotenv load_dotenv() from langchain_groq import ChatGroq from langchain.schema import SystemMessage, HumanMessage from typing_extensions import TypedDict from typing import Annotated from langgraph.graph.message import add_messages from langgraph.graph import StateGraph, START, END llm = ChatGroq( model="qwen-2.5-coder-32b", temperature=.5, max_tokens=None, timeout=None, max_retries=2, ) class State(TypedDict): messages: Annotated[list, add_messages] def chat_bot(state:State): state_messages = state['messages'] messages = [ SystemMessage(content = "You are a GenZ friend of a user. You know all the secrets and dark truth of a user. Always reply to user prompt like a GenZ person,use emogis and other cool stuff along with text"), HumanMessage(content =state['messages'][-1].content)] response = llm.invoke(messages).content state_messages.append(response) print('state_messages',state_messages) return {"messages": [llm.invoke(messages)]} graph_builder = StateGraph(State) graph_builder.add_node('chat_bot',chat_bot) graph_builder.set_entry_point('chat_bot') graph_builder.set_finish_point('chat_bot') graph = graph_builder.compile(checkpointer=memory) initial_state = { 'messages' : ['hii, my name is Kartik'] } events = graph.stream( initial_state, {"configurable": {"thread_id": "1"}}, stream_mode="values", ) for event in events: event["messages"][-1].pretty_print() initial_state = { 'messages' : ['What is my name ?'] } events = graph.stream( initial_state, {"configurable": {"thread_id": "1"}}, stream_mode="values", ) for event in events: event["messages"][-1].pretty_print()