Payload

All webhook payloads follow a consistent top-level structure with event-specific data nested within the data object.

subscriptionIdstring

The subscription ID.

customerIdstring

The customer ID. Returns your externalId if you provided one when creating the customer, otherwise returns the Commet publicId.

addonobject

The add-on: id and name.

featureCodestring

The feature the add-on unlocks or extends.

proratedPricenumber

The prorated amount charged at activation in rate scale (10000 = $1.00). Zero when nothing was charged.

currencystring

The subscription currency.

{
  "event": "addon.activated",
  "timestamp": "2026-06-18T09:12:00.000Z",
  "organizationId": "org_abc123",
  "mode": "live",
  "apiVersion": "2026-06-10",
  "data": {
    "subscriptionId": "sub_1a2b3c4d",
    "customerId": "user_123",
    "addon": {
      "id": "addon_5e6f7g8h",
      "name": "Extra Storage"
    },
    "featureCode": "storage",
    "proratedPrice": 25000,
    "currency": "usd"
  }
}

When this fires

When an add-on activation completes — via POST /subscriptions/{id}/addons or a customer portal purchase. Any prorated activation charge has already succeeded; proratedPrice is the amount charged (zero when the remaining period was free).

customer.state_changed fires alongside it with trigger addon_activated, reflecting the feature the add-on unlocked.

Use it to enable the add-on's feature in your app the moment it is paid.