Garnish — Craft CMS Control Panel JavaScript Toolkit

Reference for Garnish, Craft CMS's built-in JavaScript UI framework. Covers the class system, UI widgets, drag interactions, form components, accessibility helpers, and integration with Craft's CP.

This skill is scoped to Garnish itself — the JavaScript library at src/web/assets/garnish/. For PHP-side plugin development (elements, controllers, services), see the craftcms skill. For CP template markup that Garnish widgets attach to, see the craftcms skill's cp.md reference.

Companion Skills — Load When Needed

• craftcms — Load when the task involves PHP asset bundle classes, plugin architecture, or CP template markup that Garnish widgets attach to. Skip for pure JavaScript refactoring, Garnish API questions, or JS-only tasks.
• craft-php-guidelines — Load only when editing PHP files (asset bundle classes, controllers that register JS). Skip for pure JS work.

Documentation

• Garnish source: src/web/assets/garnish/src/ in the Craft CMS repository
• No official external documentation exists — this skill IS the documentation.

Use WebFetch on Craft's class reference (https://docs.craftcms.com/api/v5/) when looking up PHP-side asset bundle registration.

Common Pitfalls (Cross-Cutting)