Card Issuance › Webhook

Card Transaction Updates

Emitted after a transaction callback, automatic reconciliation or query-based backfill is processed, with the public transaction and card IDs and their actual status.

Event Types

Event	When Emitted
`card.transaction.updated`	Card transaction received or its status updated

Delivery Contract

We send a POST request with application/json to your configured endpoint, with a 10-second timeout.
Any 2xx response acknowledges receipt. Non-2xx responses and timeouts trigger retries with backoff.
Four request headers: content-type · z-signature · z-event-id · z-event-type。
Deduplicate by z-event-id — the same event may be delivered more than once.

Event payloads contain only IDs and status

There are no amounts, asset codes, card number fragments or risk-control reasons. This is a security boundary: the webhook endpoint is your service, whose transport and storage we cannot guarantee. The GET /v1/<resource>/{id} endpoint applies API key, scope and on-behalf-of checks. Fetch details using data.id; do not use webhook payloads as the source of amounts for your ledger.

Event Details

card.transaction.updated Card transaction received or its status updated

When Emitted

Sent after processing a normal transaction callback, automatic reconciliation, or an operations query that backfills a record. data.id is the ctx_ resource ID from the transaction list; data.card_id is the crd_ card ID. Retrieve through GET /v1/cards/{id}/transactions. authorized means authorized and awaiting settlement; do not treat it as settled. Identical snapshots of the same local transaction use the same event_id; recipients must deduplicate by event_id. Sandbox transaction simulation uses the same processing flow, with notifications delivered in the sandbox environment. bank_fee is the bank fee; zinfra_fee is the zinfra fee, currently "0" for all cards. Both are integer strings in minor units, with currency and precision supplied by fee_currency and fee_scale. These are cumulative transaction fee snapshots, not additional fees charged for each notification; authorization fees may change at settlement. original_amount / original_currency preserve the upstream transaction’s original currency and amount text. bill_amount is the card-currency bill amount, an integer string in minor units using the same source as the list: the stored settlement amount or authorization hold, without on-demand currency conversion. bill_amount is omitted when no bill amount is known. GET /v1/cards/{id}/transactions remains authoritative for details.

Payload

{
  "event_id": "evt_06a0d3fbbe074aa98809e2b90588b123",
  "event_type": "card.transaction.updated",
  "created_at": "2026-09-08T05:45:00Z",
  "merchant_id": "acme",
  "livemode": true,
  "data": {
    "object": "card_transaction",
    "id": "ctx_11111111-2222-4333-8444-555555555555",
    "card_id": "crd_aaaaaaaa-bbbb-4ccc-8ddd-eeeeeeeeeeee",
    "external_member_id": "u_88123",
    "status": "authorized",
    "status_version": 1788846300000,
    "bank_fee": "30000",
    "zinfra_fee": "0",
    "fee_currency": "USD",
    "fee_scale": 6,
    "original_amount": "8.0000",
    "original_currency": "HKD",
    "bill_amount": "1020000"
  }
}

Signature Verification

The signature verification procedure is the same for all events. See Webhook Overview; use the Signature Debugger to compare signing strings character by character.