Skip to main content
Custom field changes (custom_field.changed) fires when the value of one of your custom fields changes on a store. It turns your own CRM data into an event: set an onboarding stage, and a flow reacts to it.

​
When it fires

On every write path (a value edited by hand on a store, pushed from your backend through the custom field values API, or written by a Populate custom field action), but only when the stored value actually changes. Re-writing the same value is not a change, and fires nothing.

​
Watching one field or any

The trigger takes an option:
  • A specific field: the flow only runs when that definition changes.
  • Any custom field: the flow runs whenever any of the app’s fields changes on a store.
A flow runs once per changed field. Pushing five fields in one API call fires each watching automation once per field that really changed, not once for the batch.

​
Loops, and the two guards

Because a Populate custom field action is itself a write, this trigger can start a flow that writes a field that starts another flow. Meridian bounds that in two places:
  • An automation never re-runs on the change it caused. The flow that wrote the field is skipped for that change, which kills the self-feeding loop, the common case and the one you’ll hit by accident.
  • Automation-to-automation chains stop after 3 hops. A ring where flow A writes field 1, flow B triggers on field 1 and writes field 2, and A triggers on field 2 is cut off at the cap.
Writes by a person or by your backend always start a fresh chain, so the cap only ever truncates automation-caused chains.

​
What it carries

The store’s variables, including every custom field as {{custom_field_<handle>}}, so an email can quote the value that just changed, and a variable condition can branch on it.

​
Building on it

  • Watch an “onboarding stage” field and send the email for each stage as your backend advances it.
  • Watch an “account owner” field to notify the person now responsible.
  • Watch any field and branch inside the flow, when several fields should lead to the same follow-up.
Last modified on August 21, 2026