6/6 — Store & next step
The generated tags can be stored along with the document chunk:
{
"page": page_number,
"text": chunk_text,
"tags": tags
}
The bigger picture:
PDF → Chunk → LLM → Tags → Metadata → Vector Store → RAG
Spent some time learning LangChain and built a small GenAI tag builder for PDFs.
The flow:
📄 PDF → 🔪 Chunk text → 🤖 LLM generates 3–5 tags → 🗂️ Store as JSON/vector data
Simple project, but a great way to understand how document processing + LLMs + RAG building blocks
5/6 — Generate tags
Now I use Claude to generate 3–5 meaningful tags for each chunk:
from langchain_anthropic import ChatAnthropic
llm = ChatAnthropic(model="claude-sonnet-4-6")
prompt = f"""
Generate 3-5 meaningful tags for this text.
Return only the tags.
Text:
4/6 — Split into chunks
Large documents need to be broken into smaller pieces.
from langchain.text_splitter import RecursiveCharacterTextSplitter
splitter = RecursiveCharacterTextSplitter(
chunk_size=1000,
chunk_overlap=100
)
chunks = splitter.split_documents(
3/6 — Load the PDF
I used PyPDFLoader to read the PDF:
from langchain_community.document_loaders import PyPDFLoader
docs = PyPDFLoader("file.pdf").load()
Now the PDF content is available as LangChain documents.
2/6 — Install
First, install the required packages:
pip install langchain langchain-community pypdf langchain-anthropic
This gives us the basic building blocks for PDF loading, text processing and Claude integration.
1/6
Spent some time learning LangChain and built a small GenAI tag builder for PDFs.
The goal was simple:
📄 PDF → 🔪 Split → 🤖 Generate tags → 🗂️ Store metadata
Here’s how I built it 👇
🔧 How I built it:
1️⃣ Load the PDF using PyPDFLoader
2️⃣ Split the document into smaller chunks using RecursiveCharacterTextSplitter
3️⃣ Send each chunk to an LLM using ChatAnthropic
4️⃣ Generate 3–5 meaningful tags for each chunk
5️⃣ Store the tags as JSON/dictionary or use
1/6
Spent some time learning LangChain and built a small GenAI tag builder for PDFs.
The goal was simple:
📄 PDF → 🔪 Split → 🤖 Generate tags → 🗂️ Store metadata
Here’s how I built it 👇