Retrieval Augmented Generation

Every six months, someone declares RAG dead. The argument is always the same: “Now that GPT-4.1 has 1M tokens and Gemini 2.5 Pro handles 2M, why bother with retrieval? Just dump everything into context.” I’ve been building production RAG systems since the LlamaIndex 0.5 days, and I can tell you: bigger context windows didn’t make RAG obsolete. They made the problem more interesting — and harder to get wrong. Here’s what the 2026 data actually shows, and what techniques deliver real results when you’re building a retrieval system that needs to work in production. ...

MCP, RAG, and AI agents are not competing technologies. They are complementary layers that solve different problems. Model Context Protocol (MCP) standardizes how AI connects to external tools and data sources. Retrieval-augmented generation (RAG) gives AI access to private knowledge by retrieving relevant documents at query time. AI agents use both MCP and RAG to autonomously plan and execute multi-step tasks. In 2026, production AI systems increasingly combine all three. ...