Matt Pocock is selling "Skills for Real Engineers. Straight from my .agents directory" as a GitHub sponsors product. The repo collected 2,447 stars in a day. VoltAgent is selling "a curated collection of 1000+ agent skills from official dev teams and the community, compatible with Claude Code, Codex, Gemini CLI, Cursor, and more" - 602 stars. Affaan M is selling "the agent harness performance optimization system. Skills, instincts, memory, security, and research-first development for Claude Code, Codex, Opencode, Cursor and beyond" - 427 stars. Mads Lorentzen, Virgilio Jr, and Rohit G are each selling variations on the same format: instruction files for AI coding tools, packaged as sponsor tiers.

The products use different labels for the same material. Pocock calls them skills. Affaan M calls them skills and instincts. VoltAgent calls them agent skills. All are markdown files that configure how Claude Code, Cursor, or similar tools behave when writing code.

Two repos are giving the files away. Multica AI published "a single CLAUDE.md file to improve Claude Code behavior, derived from Andrej Karpathy's observations on LLM coding pitfalls" - 588 stars, no sponsors tier. Freestylefly published "Prompt as Code | GPT-Image2 工业级提示词引擎与模板库，530+ 个案例逆向工程，20+ 套工业级模板，并提炼出Skills" - 2,449 stars, also free.

The question is what changed between the files being shared and the files being sold. The repos do not say, and the format is identical: markdown instructions in a dotfile or a directory. Anthropic runs a read-only mirror of community plugins for Claude Code at github.com/anthropics/claude-plugins-community, which collected 489 stars - but that is a directory, not a product, and submitting to it does not earn the submitter money.