# Sources of truth

- [Agent Skills specification](https://agentskills.io/specification) — portable
  skill contract.
- Pi's installed `skills.md` at `$PI_CONTEXT_DOCS_PATH/skills.md` — current Pi
  discovery, loading, invocation, and validation behavior.
- [Pi skills documentation](https://github.com/earendil-works/pi/blob/main/docs/skills.md)
  — repository fallback when installed docs are unavailable.
- [`references/checker.md`](checker.md) — behavior of this repository's
  structural checker; its tests are the executable contract.