I see developers trying to build "AI Chatbots" that know about their specific company data. They want the AI to read their PDFs, their internal wikis, or their past customer support tickets, and answer questions based on that data. This technique is called RAG (Retrieval-Augmented Generation). When the AI hype first started, developers thought they had to pay for expensive, dedicated "Vector Databases" like Pinecone or Milvus to do this. They added a massive layer of complexity to their stack just to store some AI data. In 2026, the Rails way to do this is much simpler. You just use PostgreSQL. By using the pgvector extension and a brilliant Ruby gem called neighbor , you can keep all your AI data perfectly synced inside your standard Rails database. You get the power of RAG without leaving the comfort of ActiveRecord. Here is exactly how to build "Chat with your Database" in 4 steps. The Mental Model: What are Embeddings? Before we code, you need to understand how AI "searches" text.…