RTK Saves 60% of Tokens. I Made It Save 90%.

RTK is one of the best tools in the Claude Code ecosystem. 28k GitHub stars, 60-90% token savings on git, test, and ls output, 34 command modules with TOML-based filters. If you use Claude Code and don't have RTK installed, go install it now. But RTK has blind spots. It doesn't compress error stacktraces. It doesn't touch npm install warnings. It passes Docker build logs through unchanged. And ANSI escape codes — spinners, progress bars, color codes — all of that noise flows straight into your context window. I forked RTK and built ContextZip to fill those gaps. Here's a direct comparison. What RTK Does vs. What ContextZip Adds Category RTK ContextZip git diff/log/status Yes Yes (inherited) ls/find/tree Yes Yes (inherited) test output (Jest, pytest) Yes Yes (inherited) cargo/rustc output Yes Yes (inherited) Error stacktraces No Yes — 5 languages ANSI/spinner cleanup No Yes — preprocessor npm/pip install noise No Yes — keeps security Docker build logs No Yes — 88% avg savings Build erro