Update main.py

main.py

@@ -12,6 +12,8 @@ from langgraph.graph.message import AnyMessage, add_messages
 from langchain_core.messages import HumanMessage, AIMessage
 from langgraph.graph import END, StateGraph, START
 from langgraph.checkpoint.memory import MemorySaver
+from langchain_community.document_loaders import DirectoryLoader
+from langchain_text_splitters import CharacterTextSplitter
 from fastapi import FastAPI
 from fastapi.middleware.cors import CORSMiddleware
 from pydantic import BaseModel