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.

statusstring

Always "trialing" for this event.

planIdstring

The plan ID.

planNamestring

The plan name.

trialEndsAtstring

ISO 8601 datetime when the trial ends.

{
  "event": "trial.started",
  "timestamp": "2026-06-23T14:30:00.000Z",
  "organizationId": "8f14e45f-ceea-4e7a-9c3d-1c2b3a4d5e6f",
  "mode": "live",
  "apiVersion": "2026-07-31",
  "data": {
    "subscriptionId": "sub_1a2b3c4d",
    "customerId": "user_123",
    "status": "trialing",
    "planId": "pln_pro_monthly",
    "planName": "Pro",
    "trialEndsAt": "2026-04-08T00:00:00.000Z"
  }
}

Trial lifecycle

Trials in Commet collect a payment method at checkout, so every trial has a clear path to revenue:

Moment	Event	What to do
Checkout completes with trial days	`trial.started`	Grant full access.
3 days before the trial ends	`trial.will_end`	Remind the customer billing starts soon.
Customer upgrades during the trial	`trial.converted`	Trial ends early, paid plan starts now.
Trial runs out	`trial.expired`	Regular billing begins automatically.

Subscriptions with status: "trialing" have full access — treat them like active in your entitlement checks.