Installation

Stop Sign needs Craft CMS 5.3 or later and PHP 8.2 or later. It has no runtime dependencies, no build step, and makes no outbound requests.

composer require justinholtweb/craft-stopsign
php craft plugin/install stopsign

That is the whole installation. The defaults warn, guard saves, and do not lock anything.

What changes immediately

• Every element editor — full-page and slideout — starts sending a heartbeat every ten seconds.
• A banner appears above the content when somebody else is in the element.
• Saving pauses to ask when somebody else is actively editing, or when the element changed while you had it open.
• Element index chips get a dot when somebody is inside that element.
• Utilities → Stop Sign appears.

Craft's own avatar stack in the editor header carries on exactly as before. Stop Sign does not replace it, hide it, or interfere with it — it keeps its own presence records for reasons covered in How it works.

What it adds to your database

Four small tables:

Table	Holds	Pruned
stopsign_presence	One row per open tab	Automatically, on garbage collection
stopsign_locks	One row per locked element	On expiry
stopsign_saves	One row per element — who last saved it	After 180 days of no saves
stopsign_collisions	The history	By the retention setting

None of them hold content. stopsign_collisions is user ids, element ids and an outcome.

Removing it

php craft plugin/uninstall stopsign

All four tables are dropped. Nothing is left behind in your content, and no element is altered by having been watched — presence and locks live entirely in Stop Sign's own tables.

If locks are enabled and something has gone wrong, release them before uninstalling:

php craft stopsign/unlock --all