I Built a VS Code Extension That Understands Your Codebase Without AI

#vscode #javascript #archsetu #opensource

A few months ago, I kept running into the same wall: opening an unfamiliar codebase — sometimes my own, six months later — and freezing. Where does this app even start? If I touch this function, what breaks? Is this code even still used?
I couldn't find a tool that answered this deterministically. So I built one.
ArchSetu
It's a VS Code extension that does static analysis on JavaScript/TypeScript projects — no AI, no API keys, no internet connection required. Everything runs locally, on your machine, instantly.
What it actually does:

Cross-file call graphs — see how every function connects across your entire project
Blast radius analysis — know exactly what breaks before you change a function
Dead code finder — functions defined but never called anywhere
Entry point detection — every route, export, and event listener, so you know where the app starts
Codebase health dashboard — complexity hotspots, largest files, coupling, all in one view

Why not just use Cursor or Copilot?
Those tools are excellent at writing new code. They're not built to deterministically map what already exists — and on large codebases, they hit context/token limits that static analysis doesn't.
ArchSetu isn't trying to replace AI coding assistants. It's meant to sit alongside them — run it before you accept a big AI-generated diff, and you know exactly what it touches before you merge.
Where it's at right now
Very early — just published, free, looking for honest feedback from real projects. If you try it on something real and it breaks, confuses you, or misses something,