An AI skill is a Markdown file your coding agent reads and obeys. GitHub code search currently finds 74,192 SKILL.md files installed under .claude/skills/ in public repos. We pulled a sample of 461 of those repos (plus the official Anthropic, OpenAI, and Trail of Bits catalogs), ran a static capability scan over every skill, and aggregated what they can actually do.
Sample: 392 repos with parseable skills, 17,065 skills (12,280 unique by content hash). Repos ranged from personal dotfiles to projects like Appwrite (56k stars). Aggregate stats only - this post names no repo and no skill.
The numbers
Capability
Skills
