A skill is a packaged set of instructions — defined by a SKILL.md file — that can be attached to a model request. Skills let you build reusable personas, workflows, or domain-specific assistants without repeating system prompts.
Skills are versioned. You can update a skill without breaking existing integrations that pin to an older version.
Key fields:
Skills are immutable once created. Add a new version instead of editing:
List versions:
Read-only skills (source anthropic or zylon) cannot be deleted.