Handling cancellation

When the customer clicks Cancel on the gateway card or OTP page, the gateway posts the callback with UserCancelled=true, merchantRef, and merchantSession. The package resolves the transaction, cancels it, and emits transaction:cancelled before redirecting.

sisp.on('transaction:cancelled', ({ transaction, reason }) => {
  // reason is 'user_cancelled' for a gateway cancellation
  releaseHeldStock(transaction.merchant_ref);
  console.log('cancelled', transaction.merchant_ref, reason);
});

The transaction lands in the cancelled state with merchant_response set to user_cancelled. Unknown or already-terminal transactions are redirected without an event.

Observed callback payload from the live gateway:

{ "merchantRef": "Rmqzujqavi5xf96", "merchantSession": "Smqzujqavctgcpo", "UserCancelled": "true" }

Next: Handling failed payments