Refunds a previously created transaction identified by your system's own custom_transaction_id.

Full refund

Omit the request body (or send no items) to fully reverse the loyalty impact of the original transaction:

• Coupons — any coupons redeemed as part of the transaction are returned to the member and become available again.
• Earned points — points credited to the member's primary wallet for this transaction are deducted.
• Burned points — points spent (burned) during the transaction are returned to the member's primary wallet.

Partial refund

Send an optional items array to refund only specific line items. Points are adjusted proportionally to the refunded share of the transaction (by line net amount):

{
  "items": [
    { "sku": "ABC-1", "qty": 1 }
  ]
}

• Earned points — a proportional share of earned points is clawed back.
• Burned points — a proportional share of burned points is returned.
• Coupons — stay redeemed on a partial refund. They are returned only when the transaction becomes fully refunded (explicit full refund, or when remaining refundable quantity reaches zero).

If a partial refund (or a series of them) exhausts all remaining item quantities, the transaction is automatically promoted to a full refund.

Usage notes

Use this endpoint when a sale is voided or returned in your POS or e-commerce system.

• A full refund of an already refunded transaction is rejected (no duplicate reversals).
• Partial refunds may be called more than once as long as requested sku/qty does not exceed remaining refundable quantity.
• Duplicate SKUs in one request are summed; multiple lines with the same SKU are matched FIFO.