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

RTK is a popular Claude Code tool offering 60-90% token savings via 34 command modules, but it misses error stacktraces, npm warnings, Docker logs, and ANSI codes. The author forked RTK to create ContextZip, adding 6 new filters (error stacktrace compression, ANSI preprocessor, package install compression, Docker build compression, build error grouping, and web page extraction) that push total savings to 70-90% on typical debugging sessions. ContextZip preserves all of RTK's existing filters while guaranteeing error messages are never removed.