langchain-pdfbot

📄 LangChain PDFChat

LangChain PDFChat is a lightweight Node.js library that helps you build a local question–answering chatbot over any PDF.
It uses local embeddings (so you don’t pay per token) and powerful Groq LLM to generate answers strictly based on the PDF content.

✅ Only answers questions if info is found in the PDF
✅ Fast: Uses in-memory vector search
✅ Easy to use: Just point to a local PDF, ask questions

✏️ How it works

• You load a PDF file from your local system.
• The tool splits & embeds the PDF content in memory.
• A retriever fetches only the relevant chunks for each user question.
• The question and chunks go to the Groq LLM to generate an answer.
• If the answer isn't in the PDF, it says: "Not relevant question".

🚀 Quick Start

Step 1: Install

npm install langchain-pdfbot

Step 2: Get your free Groq API key

• Sign up at: https://console.groq.com
• Go to Settings → API Keys → Create API Key
• Copy your new API key (starts with gsk_...)

Step 3: Add your API key to .env

GROQ_API_KEY=your_groq_api_key_here

Step 4: Use in your code

// index.js

import {createLlm} from "./model/llm.model.js";
import {createPdfQaTool} from "./tools/pdfQa.js";

const llm = createLlm({ apiKey: <groq-api-key>, model: "llama3-70b-8192" });

const askQuestion = await createPdfQaTool("./pdfs/sample.pdf", llm);

const answer = await askQuestion("what is array? ");
console.log("Answer:", answer);