Real data. One developer. One open-source Rust binary. The numbers don't lie. Let me show you something. A developer ran rtk gain after using a tool called RTK for a while. Here's what their dashboard showed: ! Total commands: 15,720 Input tokens: 146.3M Output tokens: 16.3M Tokens saved: 130.0M (88.9%) Total exec time: 788 minutes Efficiency meter: ████████████░░ 88.9% Enter fullscreen mode Exit fullscreen mode 130 million tokens saved. 88.9% efficiency. Not a benchmark. Not a simulation. An actual developer's real session history. That's the receipt. Now let me explain what's happening — and why you should care. The Leak Nobody Warned You About You set up Claude Code, Cursor, or Copilot. You start building. You feel productive. The AI is running commands, reading files, making changes. It feels like the future. What you don't see is the token leak happening on every single shell command. Your AI runs git push . Git responds with: Enumerating objects: 5, done. Counting objects: 100% (5/5), done.…