Automation Triggers

Configure an automation to run automatically whenever a specific canvas event occurs — no manual Run click needed.

By default, automations run manually when you click Run. You can instead configure an automation to fire automatically in response to a project event — for example, every time an entity is placed, every time the selection changes, or once when the project opens.

The trigger is configured using the Trigger selector pill in Row 2 of the expanded IDE toolbar. It appears as a compact pill showing either "▶ Start manually" or "⚡ [event name]".

Open the trigger selector

Open the expanded IDE (click Edit script or the expand icon). The Trigger selector pill is in Row 2 of the toolbar, on the left side.

Click the pill to open the trigger dropdown. The dropdown lists all available trigger options.

Available trigger events

The trigger dropdown offers:

Manual trigger (default) — the automation only runs when you click Run
On entity placed — fires after a new entity is added to the canvas
On entity deleted — fires after an entity is removed
On entity moved — fires after an entity is repositioned
On entity resized — fires after an entity changes size
On entity type changed — fires when an entity is converted to a different type
On layer changed — fires when a layer's visibility, lock, or name changes
On selection changed — fires when the canvas selection changes
On structure regenerated — fires after a parametric structure is rebuilt
On terrain modified — fires after a terrain mesh or height field changes
On project opened — fires once when the project is first loaded

Select an event to set it as the trigger. The pill updates to show the event name with a ⚡ icon.

TIP

Use On entity placed + filter by type to build reactive automations — for example, automatically align every new sprinkler to the nearest irrigation pipe when it is placed.

Pause or resume auto-runs

When a non-manual trigger is configured, an On/Off toggle appears beside the trigger pill. Click it to pause or resume automatic runs for this automation.

On (green) — the automation fires automatically on the configured event
Off (muted) — the trigger is configured but dormant; manual Run still works

The pill changes to a muted style when paused, showing a "paused" label.

A master switch for all automations is available in project Settings → Automations. When the master switch is off, all automation auto-runs are blocked regardless of individual On/Off toggles; the pill shows a "blocked" label.

Add filter rules

Most event triggers can be filtered so the automation only fires for matching entities.

When a non-manual, non-project-opened trigger is active, an Add rules button (Filter icon) appears beside the On/Off toggle. Click it to open the Match Rules popover.

The Match Rules popover lets you build AND/OR filter groups. Each rule row specifies:

Property — the entity property to filter on (e.g. entity type, layer, name, class)
Operator — equals, contains, starts with, etc.
Value — the value to match against

Multiple rule rows within a group use AND logic. Multiple groups use OR logic.

For On layer changed events, the filter is a layer selector rather than entity type rules.

Events with no entity payload (On project opened, On structure regenerated, On terrain modified) have no filter UI — they always fire unconditionally.

TIP

Filter triggers narrowly to avoid automations firing too frequently. An unfiltered On entity moved trigger fires every time any entity is dragged — add a type filter to restrict it to the specific entity type you care about.

INFO

Re-entrant triggers are automatically blocked. If a running automation modifies the canvas in a way that would fire the same event again, the dispatcher ignores the second dispatch. This prevents automations from triggering themselves in an infinite loop.

Review auto-triggered runs in History

Auto-triggered runs execute silently — no panel opens and no notification appears. To see what background runs have done, open the automation's editor and click the History tab in the editor sidebar. Rows with a ⚡ auto badge represent event-triggered runs. Expand any row to see the trigger event name, timestamp, duration, number of edits made, and any error that occurred.

Run history is retained on this device across page reloads (the most recent runs, oldest pruned over time), giving you an audit trail of recent background automation activity.

TIP

Develop and test a new automation with the Manual trigger first. Only switch to an event trigger once the automation behaves correctly — this prevents accidental edits to your drawing during debugging.

WARNING

Auto-triggered runs are fully undoable with Ctrl+Z (Cmd+Z on Mac), but each background run is a single undo step that may reverse many entity changes at once. If an automation fires repeatedly during a design session, you may need to undo multiple steps to reach the state you want. Use the History tab to see exactly what each run changed before undoing.

Frequently Asked Questions

Can one automation have multiple triggers?

No — each automation has exactly one trigger at a time. To react to multiple events, create a separate automation for each event. Alternatively, use a broad entity-type filter on a single On entity placed trigger to cover all the entity types you want to respond to from a single placement event.

What happens if a triggered automation errors?

The error is recorded silently in the History tab with a red indicator. The automation does not retry automatically and no notification interrupts your work. Fix the script in the code editor — the next trigger event will fire a clean run.

Will an automation trigger itself if it moves or places entities?

No. The dispatcher blocks re-entrant triggers. While an event-triggered run is in progress, any new dispatch of the same or any other event is ignored. This prevents infinite loops when an automation modifies entities that would otherwise re-fire the same event.

Does the master switch in project settings affect manual runs?

No. The master switch (Project Settings → Automations) only blocks automatic event-triggered runs. Manual Run always works regardless of whether the master switch or the per-automation toggle is off.

How do I filter On layer changed triggers by layer?

On layer changed uses the same Match Rules panel as the entity events. Add a rule row, choose the Layer property, and set the value to the layer you want to restrict the trigger to. Entity-property filters (type, name, layer, and others) are available for all the filterable events.