Event: payment_method.updated

When it fires

An existing member went back through hosted checkout to replace their default payment method — a checkout resolved with purpose pur: 1 (see Updating a payment method). Topiic captured a fresh card token, stored it as a new PaymentMethod, and made it the member’s default. No plan or subscription is created or changed.

Like the checkout.* events, this delivers only to the API key whose signing secret produced the deep link — it does not fan out to every key on the merchant.

Headers

Same envelope as other events: Topiic-Event-Id, Topiic-Idempotency-Key, Topiic-Signature. See Verifying signatures.

Body

{
  "id": "b3d9f1a2-…",
  "type": "payment_method.updated",
  "createdAt": "2026-07-05T22:14:03.902Z",
  "merchantId": "e7d2f1a8-9c4b-4d62-8a3f-1b5c7e9d0f24",
  "data": {
    "sessionId":       "7e6d5c4b-3a2f-1e0d-9c8b-7a6f5e4d3c2b",
    "externalRef":     "cust_42",
    "memberId":        "1a2b3c4d-5e6f-7a8b-9c0d-1e2f3a4b5c6d",
    "paymentMethodId": "9f8e7d6c-5b4a-3c2d-1e0f-9a8b7c6d5e4f",
    "last4":           "4242",
    "brand":           "Visa"
  }
}

data fields

Field	Type	Notes
sessionId	UUID	The Topiic checkout session id.
externalRef	string | null	Whatever you passed as ref in the deep link.
memberId	UUID	The member whose default payment method changed (the mem from the deep link).
paymentMethodId	UUID	The new default PaymentMethod holding the gateway token.
last4	string	Last four digits of the new card, for display.
brand	string	Card brand (e.g. "Visa", "Mastercard").

What to do on receipt

1. Verify the signature, dedupe on event.id.
2. Find the customer on your side via memberId (or externalRef).
3. Update any stored card display metadata (last4, brand) so your UI shows the current card.
4. Return 2xx within 10 seconds.

Note

Existing subscriptions keep billing against the member’s default payment method, so once this event lands, future charges use the new card automatically — you don’t need to re-point subscriptions yourself.