# Sources

| Topic | URL | Used for |
|-------|-----|----------|
| Agent Skills spec | https://agentskills.io/ | Package format |
| agentskills specification | https://github.com/agentskills/agentskills/blob/main/docs/specification.mdx | Field rules |
| vercel-labs/skills | https://github.com/vercel-labs/skills | npx install CLI |
| skill-source-citations | https://github.com/arenukvern/skill_steward/tree/main/skills/skill-source-citations | Citation practice |
| skill-eval-improve | https://github.com/arenukvern/skill_steward/tree/main/skills/skill-eval-improve | Eval loop |
| Codex skills | https://developers.openai.com/codex/skills | Codex `agents/openai.yaml`, skill activation, distribution boundary |
| Zed skills | https://zed.dev/docs/ai/skills | Skill format, path rules, and invocation controls |
| Cursor skills | https://cursor.com/docs/skills.md | Skill paths, top-level scoping fields, and migration behavior |

## Changelog

- 2026-05-29: initial
- 2026-06-05: added current Codex, Cursor, and Zed skill authoring references
