On this page

Transaction decision webhooks

Myaza sends one concise summary when a transaction is assessed and again if its effective decision changes.

Events

Event	Use it for
`fraud.transaction.assessed`	Apply the first transaction decision.
`fraud.decision.changed`	Replace the previous decision with the new effective decision.
`event.flagged`	Legacy compatibility for non-allow decisions. New integrations should use the events above.

Example

json

{
  "id": "evt_transaction_01",
  "event": "fraud.transaction.assessed",
  "createdAt": "2026-08-15T15:02:12.884Z",
  "data": {
    "externalTransactionId": "txn_928401",
    "activityId": "act_tx_01",
    "decisionId": "dec_tx_01",
    "decision": "review",
    "summary": {
      "outcome": "review",
      "title": "Review required",
      "reason": "A high-risk transaction rule matched.",
      "score": 82,
      "riskLevel": "high",
      "matchedRules": 1,
      "nextAction": {
        "type": "review_activity",
        "label": "Review transaction"
      }
    }
  }
}

Use data.summary for normal integration logic:

Deduplicate by the envelope id.
Branch on summary.outcome.
Display summary.reason when a person needs context.
Follow summary.nextAction when it is not none.

The same payload can include detailed rule, screening, billing and Travel Rule evidence. Store that evidence for audit or open the transaction read API when you need it, but do not recompute Myaza's decision from those details.

Delivery order is not guaranteed. A later fraud.decision.changed event is authoritative for the effective decision.