Claude Code Is Wasting Your Tokens. I Fixed It in 3 Weeks Without Writing a Single Line of Code.

I burned through my Claude Code context window three times in one session. The third time, I snapped. I was debugging a Node.js app. Claude ran npm install , and 150 lines of deprecated warnings flooded my context. Then a stacktrace — 30 lines of node_modules frames, only 2 lines of my actual code. Then docker build dumped 50 lines of layer hashes. By the time I got back to the actual bug, Claude had forgotten the code I'd shown it 10 minutes ago. The context window was full of noise. That night I found RTK — Rust Token Killer. An open-source CLI proxy that compresses command output before it reaches Claude Code. 28k stars, 60-90% savings on git, test, and ls output. Impressive. But it didn't touch error stacktraces. Or web pages. Or npm install noise. Or Docker builds. So I forked it. The Experiment: Can Claude Code Build Its Own Tool? Here's the part that gets weird. I built ContextZip — a 40-module Rust CLI with 1,056 tests — using Claude Code itself. The tool that compresses Claude