How I Built an Agentic Coding CLI from Scratch

I wanted to understand how AI coding tools actually work under the hood. Not just use them — but build one myself. So I built AgentCode : an open-source, multi-model agentic coding CLI. You type a request in plain English, and it reads your codebase, writes code, runs tests, manages git — all autonomously. Here's what I learned building it. The Core Insight: It's Just a Loop Every agentic coding tool — no matter how polished — runs the same fundamental pattern: while needs_follow_up : 1. Send co