agentskills.io-compatible.
SKILL.md format with YAML frontmatter, open standard. Authored skills move with you across compatible agents.
Author or import a SKILL.md. The registry parses frontmatter, runs all three security scans, and stores the content hash.
When the agent system prompt builds, only skill names and short descriptions inject. The model knows skills exist without seeing their full content.
Agent calls use_skill or operator types /skill name. The full methodology body injects into the system prompt at Priority 3.5, wrapped in [SKILL CONTENT START]/[SKILL CONTENT END] boundary markers.
The skill's content hash recomputes and compares to the stored hash. If something modified the file out-of-band, activation fails closed.
Skills declaring chain steps execute their pattern: sequential (step by step), parallel (race), conditional (branch on output), feedback loop (iterate until done), context fork (try variations and pick best).
Two skills, same task, multiple model providers. The eval framework scores each run and surfaces which combination actually performed better.