SkillZip compresses skill libraries as executable graphs, 3.46x smaller with 99.2% of dependencies intact.

arXiv 2608.05604 names the mismatch precisely: current systems retrieve skills as packages but compress them as prose, which destroys the execution contract. SkillZip does contract-preserving compression over section-level graphs, rewriting recurring valid motifs into reversible macros while preserving boundary signatures and dependencies. 3.46x compression, 99.2% dependency preservation, 98.7% verifier reachability, up to 12.2 points of task improvement. A companion pass (ReZip) folds new skills in and revises macros from execution feedback. Demonstrated from 200 to 100,000 skills. Directly relevant if your .claude/skills directory has outgrown its context budget.