DEV Community

Cover image for Chat With Your PDFs: Part 2 - Frontend - An End to End LangChain Tutorial. Build A RAG with OpenAI.
Austin Vance for Focused

Posted on

11

Chat With Your PDFs: Part 2 - Frontend - An End to End LangChain Tutorial. Build A RAG with OpenAI.

In this video we are going to dive into part two of building and deploying a fully custom RAG with @LangChain and @OpenAI. In this tutorial, code with me, video we will take the LangServe pipeline we developed in Part 1 and build out a fully functioning React & Typescript frontend using TailwindCSS.

The video did end up getting pretty long so we will deploy the app to @digitalocean_staff and to @LangChain in Part 3!


Just to remember what happened so far:

In Part One You will Learned:

  • Create a new app using @LangChain's LangServe
  • ingestion of PDFs using @unstructuredio
  • Chunking of documents via @LangChain's SemanticChunker
  • Embedding chunks using @OpenAI's embeddings API
  • Storing embedded chunks into a PGVector a vector database
  • Build a LCEL Chain for LangServe that uses PGVector as a retriever
  • Use the LangServe playground as a way to test our RAG
  • Stream output including document sources to a future front end.

In Part 2 we will focus on:

  • Creating a front end with Typescript, React, and Tailwind
  • Display sources of information along with the LLM output
  • Stream to the frontend with Server Sent Events

In Part 3 we will focus on:

  • Deploying the Backend application to @DigitalOcean & @LangChain's LangServe hosted platform to compare
  • Add LangSmith Integrations
  • Deploying the frontend to @digitalocean_staff's App Platform
  • Use a managed Postgres Database

In Part 4 we will focus on:

  • Adding Memory to the @LangChain Chain with PostgreSQL
  • Add Multiquery to the chain for better breadth of search
  • Add sessions to the Chat History

Github repo

https://github.com/focused-labs/pdf_rag

Top comments (0)

Sentry image

See why 4M developers consider Sentry, “not bad.”

Fixing code doesn’t have to be the worst part of your day. Learn how Sentry can help.

Learn more

👋 Kindness is contagious

Please leave a ❤️ or a friendly comment on this post if you found it helpful!

Okay