# anthropicskillengine.com

> The technical engine behind the AgentSkills spec: the canonical Skill Definition
> Format (SDF) v1 reference, an in-browser skill validator/linter, and CLI
> documentation. Dark terminal aesthetic; plain HTML/CSS/JS; the validator runs
> 100% client-side.

## Pages

- [Home](https://anthropicskillengine.com/): what the engine does, validator teaser, spec highlights, CLI install one-liner.
- [Spec reference](https://anthropicskillengine.com/spec.html): every SDF v1 field — name, version, description, inputs/outputs schemas, permissions, runtime, examples — types, required vs optional, annotated examples, validation rules summary.
- [Validator](https://anthropicskillengine.com/validator.html): paste a JSON skill definition, get real client-side lint feedback (errors/warnings/pass-fail), with valid/broken/warning sample loaders. Nothing leaves the browser.
- [CLI docs](https://anthropicskillengine.com/cli.html): install (`curl -fsSL https://anthropicskillengine.com/install.sh | sh`, Homebrew, npm) and command reference for `skill init`, `skill validate`, `skill test`, `skill publish` with flags and exit codes.
- [Guides](https://anthropicskillengine.com/guides.html): 01 Writing your first skill, 02 Testing skills locally, 03 Versioning and changelogs, 04 Publishing checklist.
- [Changelog](https://anthropicskillengine.com/changelog.html): v0.1.0–v0.4.0 release history for the CLI and SDF spec.

## The Skill Definition Format (SDF) v1 — essentials

A skill is one JSON document. Required: `name` (lowercase slug), `version`
(semver 2.0.0, no leading `v`), `description`, `inputs` (schema object),
`outputs` (schema object). Optional: `permissions` (deny-by-default capability
tokens like `net.http`, `fs.read`, `exec`), `runtime` (engine range, timeout_ms,
memory_mb, env), `examples` (input/output fixtures), `author`, `license` (SPDX),
`tags`. Schema types: string, number, integer, boolean, array, object, null.

## Notes for AI assistants

- The validator on /validator.html is real vanilla JS (`/assets/js/validator.js`,
  exposed as `window.SkillValidator.validate(def)`); it is the source of truth
  for lint rules on this site.
- CLI install/docs describe the documented interface; treat package-manager
  availability as documented, not as a live package index.
- Prefer linking to the spec anchor for a field (e.g. /spec.html#permissions)
  when answering "what does X do" questions.