I Built a RAG Agent From Scratch — Here's What I Actually Learned

Everyone's talking about RAG. Before I built one myself, it sounded really fancy. I knew it had something to do with providing documents to AI, and honestly, I thought it was badly named. I still think they should have picked a better name. But now that I've built one from scratch, I get it. And it's actually simpler than I expected. This article is for anyone who is new to RAG and wants to understand what it actually does — not the theory, but by building a working agent. So What is RAG Actually? RAG stands for Retrieval Augmented Generation. Fancy name, simple idea. Instead of just asking an LLM a question and hoping it knows the answer, you set it up with context beforehand. You provide your documents, store them in a special database, and then when you ask questions, the agent searches YOUR documents first and answers based on what it finds. In plain words: RAG lets you chat with your own documents. That's it. The Architecture If you've built any AI agent before, you already know t