Document-Based Question Answering Chatbot with Memory Using LangChain and LangGraph

project
gen-ai
chatbot
LLM
LangChain
Author

Akshara Soman

Published

November 13, 2024

Modified

November 13, 2024

In this project, I explored how memory could be incorporated into a question-answering (QA) system over documents using LangChain and LangGraph, two powerful libraries designed for rapid development of language applications.

Project Overview

In this article, I’ll walk you through my recent project, which combines Retrieval-Augmented Generation (RAG) pipelines with memory integration. Here, the chatbot not only searches through documents for relevant answers but also retains memory of the ongoing conversation. This is particularly valuable for tasks where users need consistent interactions, such as customer support, educational assistance, or domain-specific inquiries.

Problem Statement

Build a chatbot that answers user queries based on an uploaded document, with memory to maintain context across interactions.

Tools and Technologies Used

LangChain: Provides tools for building language model-driven applications, including powerful utilities for working with RAG architectures. LangGraph: Complements LangChain by enabling the use of graph databases to store and retrieve contextually relevant data efficiently, optimizing memory integration. RAG Pipeline: Combines retrieval and generation capabilities to source information from documents and provide concise, natural language responses.

The Architecture: RAG Pipeline with Memory

A Retrieval-Augmented Generation (RAG) pipeline generally consists of two key components:

Retriever: Searches for relevant information within documents. Generator: Generates a coherent response based on the retrieved information. In this project, I took a step further by incorporating memory into the RAG pipeline, enabling the chatbot to “remember” past queries and responses within a session. This feature enhances response relevance and continuity in multi-turn conversations, where understanding previous interactions is essential.

Implementation Details

Step 1: Setting Up the RAG pipeline

<< add rag diagram and explanation >> << add langchain code snippet overview : obs >>

Step 2: Integrating Memory with LangGraph

Memory integration is where LangGraph shines. By storing conversation history within a graph database, LangGraph allows the bot to access past interactions and improve its contextual understanding in real-time.

<< add langgraph details/diagram from obs >>

Code

Github Repository: link

Direct link to the notebook: << add if needed >> << add descp on all imp files if needed >>

Chatbot in Action

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Advantages of Memory-Enhanced QA

Incorporating memory into the RAG pipeline has several benefits:

  • Improved User Experience: Users experience a natural flow of conversation without needing to rephrase or reintroduce context.
  • Enhanced Response Accuracy: Memory allows the bot to build on prior responses, making it ideal for complex query chains.
  • Use of Proprietary Databases: RAG over documents enables the chatbot to retrieve answers from proprietary databases without requiring additional training on the data, making it adaptable for secure, domain-specific applications.

Challenges and Future Improvements

One key challenge in implementing memory-enhanced QA systems is selecting the optimal components—such as the language model (LLM), embedding techniques, and vector database. Each choice impacts the system’s performance, efficiency, and cost. For instance, different LLMs may vary in response quality, while embedding methods and vector databases can influence retrieval speed and accuracy. Moving forward, evaluating and contrasting these components in various contexts could help fine-tune the pipeline for specific requirements.

Possible Extensions - Ideas

  1. Compare performance of different language models, embedding techniques, and vector databases for memory-enhanced QA systems across various application contexts.

Credits

If you have suggestions or ideas to collaborate, please drop an email.