GPT-4 & LangChain - Create a ChatGPT Chatbot for Your PDF Docs

Use the new GPT-4 api to build a chatGPT chatbot for Large PDF docs (56 pages used in this example).

Tech stack used includes LangChain, Pinecone, Typescript, Openai, and Next.js. LangChain is a framework that makes it easier to build scalable AI/LLM apps and chatbots. Pinecone is a vectorstore for storing embeddings and your PDF in text to later retrieve similar docs.

Tutorial video

Get in touch via twitter if you have questions

The visual guide of this repo and tutorial is in the visual guide folder.

If you run into errors, please review the troubleshooting section further down this page.

Development

Clone the repo

git clone [github https url]

Install packages

pnpm install

Set up your .env file

Copy .env.example into .env Your .env file should look like this:

OPENAI_API_KEY=

PINECONE_API_KEY=
PINECONE_ENVIRONMENT=

Visit openai to retrieve API keys and insert into your .env file.
Visit pinecone to create and retrieve your API keys.

In the config folder, replace the PINECONE_INDEX_NAME and PINECONE_NAME_SPACE with your own details from your pinecone dashboard.
In utils/makechain.ts chain change the QA_PROMPT for your own usecase. Change modelName in new OpenAIChat to a different api model if you don't have access to gpt-4. See the OpenAI docs for a list of supported modelNames. For example you could use gpt-3.5-turbo if you do not have access to gpt-4, yet.

Convert your PDF to embeddings

In docs folder replace the pdf with your own pdf doc.
In scripts/ingest-data.ts replace filePath with docs/{yourdocname}.pdf
Run the script npm run ingest to 'ingest' and embed your docs
Check Pinecone dashboard to verify your namespace and vectors have been added.

Run the app

Once you've verified that the embeddings and content have been successfully added to your Pinecone, you can run the app npm run dev to launch the local dev environment and then type a question in the chat interface.

Troubleshooting

In general, keep an eye out in the issues and discussions section of this repo for solutions.

General errors

Make sure you're running the latest Node version. Run node -v
Make sure you're using the same versions of LangChain and Pinecone as this repo.
Check that you've created an .env file that contains your valid (and working) API keys.
If you change modelName in OpenAIChat note that the correct name of the alternative model is gpt-3.5-turbo
Pinecone indexes of users on the Starter(free) plan are deleted after 7 days of inactivity. To prevent this, send an API request to Pinecone to reset the counter.

Pinecone errors

Make sure your pinecone dashboard environment and index matches the one in your config folder.
Check that you've set the vector dimensions to 1536.
Switch your Environment in pinecone to us-east1-gcp if the other environment is causing issues.

If you're stuck after trying all these steps, delete node_modules, restart your computer, then pnpm install again.

Credit