caveman: terse-output skill, 75k stars in 11 weeks
GitHub JuliusBrussee/caveman: a TypeScript skill for 30+ agent platforms that asks the agent to drop filler. 75k stars, MIT, 65% output-token reduction.
ponytail: MIT YAGNI skill cuts AI agent code by 80–94%
Dietrich Gebert's ponytail v4.6.0 (2026-06-15): 17.9k stars, 8 releases in 4 days. MIT YAGNI skill for Claude Code, Codex, OpenCode, Cursor, Aider, Kiro. Benchmark: 80–94% less code, 47–77% lower cost.