Update app.py

app.py

@@ -7,6 +7,8 @@ from langchain_openai import ChatOpenAI
 from langchain_community.vectorstores import FAISS
 from langchain_openai import OpenAIEmbeddings
 from langchain.prompts import ChatPromptTemplate, MessagesPlaceholder
+from langchain.text_splitter import RecursiveCharacterTextSplitter
+
 from langchain.agents import tool, AgentExecutor
 from langchain.agents.output_parsers.openai_tools import OpenAIToolsAgentOutputParser
 from langchain.agents.format_scratchpad.openai_tools import format_to_openai_tool_messages