Yarn for Craft CMS
Installation
Requirements
- Craft CMS 5.3 or later
- PHP 8.2 or later
Yarn creates no database tables, has no runtime dependencies and needs no build step.
Install
composer require justinholtweb/craft-yarn
php craft plugin/install yarn
A Yarn item appears in the control panel navigation, with Map, Browse, Assets, Globals and Findings beneath it.
Permissions
Two, both under Yarn in a user group’s permissions:
| Permission | What it allows |
|---|---|
| See the site’s relations | Every Yarn screen, and the Relations panel on element edit screens |
| Export the graph | Downloading the graph as JSON, CSV, DOT or Mermaid |
Settings are admin-only, and respect allowAdminChanges.
Yarn only ever shows sites the user can edit. A user with access to one site’s content cannot read another site’s graph through it.
Inside a site, Yarn respects Craft’s own view permissions. An entry in a section the user can’t view, an asset in a volume they can’t view, a category group, a global set they can’t edit, or a user when they lack View users appears as “Restricted element #id”. It keeps its relations, so counts stay accurate and a restricted page still counts as using an image, but its title and URL are hidden. Admins see everything. Element types from other plugins are shown as they are, because checking each one would mean loading every element of that type.
First run
Open Yarn → Map. The first load assembles the whole graph, which on a large site takes a few seconds; after that it is cached until an element is saved or the cache duration runs out.
If the map says “trimmed to the busiest N”, that is the Map node limit setting doing its job.
Filter by source, or double-click an element to see only its neighbourhood.
Uninstalling
php craft plugin/uninstall yarn
composer remove justinholtweb/craft-yarn
Nothing is left behind: no tables, and the only project config Yarn writes is its own settings, which go with it.