Integration Issues with LangGraph, RedisChatMessageHistory, and RunnableWithMessageHistory

[DhavalThkkar]

Description

I am currently working on integrating several components into a comprehensive chat application using LangServe and LangChain. Below, I detail the components involved and the specific issues I'm encountering. Any guidance or suggestions would be greatly appreciated.

Components and Setup:

1. History Aware Retriever and Question Answer Chain:
   • I've created a chain that consists of a history-aware retriever and a question-answer chain. These are combined using create_retrieval_chain to form the final rag_chain.

contextualize_q_system_prompt = """Given a chat history and the latest user question \
which might reference context in the chat history, formulate a standalone question \
which can be understood without the chat history. Do NOT answer the question, \
just reformulate it if needed and otherwise return it as is."""
contextualize_q_prompt = ChatPromptTemplate.from_messages(
    [
        ("system", contextualize_q_system_prompt),
        MessagesPlaceholder("chat_history"),
        ("human", "{input}"),
    ]
)
history_aware_retriever = create_history_aware_retriever(
    llm, retriever, contextualize_q_prompt
)


### Answer question ###
qa_system_prompt = """You are an assistant for question-answering tasks. \
Use the following pieces of retrieved context to answer the question. \
If you don't know the answer, just say that you don't know. \
Use three sentences maximum and keep the answer concise.\

{context}"""
qa_prompt = ChatPromptTemplate.from_messages(
    [
        ("system", qa_system_prompt),
        MessagesPlaceholder("chat_history"),
        ("human", "{input}"),
    ]
)
question_answer_chain = create_stuff_documents_chain(llm, qa_prompt)

rag_chain = create_retrieval_chain(history_aware_retriever, question_answer_chain)

2. Message History Implementation:

   • The application incorporates RedisChatMessageHistory along with RunnableWithMessageHistory. The intention is to leverage Redis for managing chat message history, tracking conversations by User ID and Conversation ID.

3. LangGraph Integration:

   • I'm attempting to integrate this setup into LangGraph. However, I'm facing challenges because LangGraph documentation suggests using Checkpoints with SQLite, and it's unclear how to integrate RedisChatMessageHistory which is essential for my application.

Issues:

• Integration with LangGraph: How can I integrate RedisChatMessageHistory within LangGraph, given that LangGraph primarily supports SQLite for Checkpoints?
• Consistent Message History: I need to ensure that message history capabilities are maintained across the entire application, allowing tracking of conversations by User ID and Conversation ID.

Resources:

• For the retrieval chain setup, please refer to the LangChain documentation on question answering with chat history: LangChain QA with Chat History.
• For details on managing persistent chat with user IDs and conversation IDs, see this example from LangServe: LangServe Chat with Persistence.

Request:

I am seeking advice or examples on how to properly integrate RedisChatMessageHistory with LangGraph in a manner that maintains full functionality of the message history features. Any insights or pointers towards documentation or similar implementations would be incredibly helpful.

System Info

System Information

OS: Linux
OS Version: #1 SMP Thu Jan 11 04:09:03 UTC 2024
Python Version: 3.11.9 (main, May 14 2024, 08:04:54) [GCC 12.2.0]

Package Information

langchain_core: 0.2.10
langchain: 0.2.6
langchain_community: 0.2.6
langsmith: 0.1.77
langchain_openai: 0.1.10
langchain_text_splitters: 0.2.1
langgraph: 0.1.2
langserve: 0.2.2

[hwchase17]

You won't be able to use RedisChatMessageHistory directly, youll need to use/implement a checkpointer, see here for an implementation in postgres: https://langchain-ai.github.io/langgraph/how-tos/persistence_postgres/

Once you do this, this should handle message history completely: https://langchain-ai.github.io/langgraph/how-tos/persistence/

[DhavalThkkar]

Thanks @hwchase17. I'll give implementing the RedisCheckpoint on my own

[DhavalThkkar]

@hwchase17 I have created an implementation for RedisSaver. It seems to work as per the example that is shared for creating PostgresSaver. Any tips on how should I go about integrating this onto LangGraph?

Should this be a part of LangGraph or will there be something like langchain-community.checkpointers.RedisSaver?

[hwchase17]

Right now we would ask that you add this as a documentation guide like https://langchain-ai.github.io/langgraph/how-tos/persistence_postgres/