Anthropic shipped Agent Skills as a Claude Code feature, but the format is really just folders of Markdown plus a manifest — nothing in it is actually bound to Claude. OpenSkills bets on that portability: it takes those skill folders and makes any AGENTS.md-aware agent load them, turning a single-vendor feature into a cross-tool convention.
What Sets It Apart
- Files, not a server. Unlike MCP, which needs a running server to expose tools, skills compile into the agent's instructions as plain text. So what: zero infra to run, works offline, and the whole skill set version-controls inside your repo.
- One source, many agents. It emits the identical
<available_skills>XML block that Claude Code uses, written intoAGENTS.md, so Cursor, Windsurf, Aider, and Codex all read the exact same skill catalog. - Stays on the official spec. It implements Anthropic's Agent Skills format rather than inventing a parallel one, so a skill authored here keeps working inside Claude Code itself instead of becoming a fork.
Who It's For
Great fit if you maintain a library of reusable agent instructions and want them to behave the same across more than one coding tool, or if you've skipped MCP purely because of the server overhead. Look elsewhere if you only ever use Claude Code — native skills already cover you — or if you need runtime tool execution and live API calls, since skills are static instruction files, not a protocol. Worth knowing: this is an independent community project, explicitly not affiliated with Anthropic, so it can trail the upstream spec when that changes.
