How to Create a RAG-based PDF Chatbot with LangChain

generated with dall-e by author

You have a PDF file with hundreds of pages that you need to read or extract specific information from, but you’re short on time or not familiar with the topics discussed in the document. What can be done in such a situation?

Wouldn’t it be great if someone could read the sections of the PDF that answer your specific questions and then have a conversation with you about that topic?

Well, you’re in luck! You can design such a helpful assistant from scratch today. How? Let’s design it together.

First, let’s determine what we need. Since we’re building a chatbot, we’ll need a Large Language Model (LLM). If you don’t have enough computing power on a server or local machine, you can opt for various pay-as-you-go API services. For this project, we’ll use the OpenAI API. You can sign up and get your API key from this link: https://platform.openai.com/signup.

Don’t forget to save this key somewhere safe, and be sure not to share it with anyone!

Now that we have the key, let’s set up our system. During this process, we will build the following graph structure.