I built an AI agent in 50 lines of Python. Here’s what everyone gets wrong about them.

You’ve been calling things agents for months. Most of them are just chatbots with extra steps. Every senior developer I know has done this at least once: you’re mid-review, someone asks how the agent loop actually works under the hood, and your brain quietly blue-screens. You’ve been using Claude, Cursor, Copilot, and Junie every single day. You’ve shipped features on top of them.