Flash Swap FAQ

The Instant Convert Payment

What is Checkout Instant Swap Payment?

When a merchant integrates Gate Pay's Checkout Payment method, users can select their preferred payment currency directly on the checkout page and complete the transaction. Gate Pay will automatically convert the selected payment currency to the order currency (also known as the settlement currency) at the exchange rate shown at the time of confirmation, and credit the merchant accordingly. Merchants do not need to handle the conversion process themselves.

How can payers use Checkout Instant Swap Payment?

When users choose the "Checkout Payment - Connect Wallet" option to pay:

1. The page will display all currently supported payment currencies.
2. Users select any payment currency and ensure they have sufficient balance to complete the payment.
3. Gate Pay will instantly swap the selected payment currency to the order currency (settlement currency) at the exchange rate shown at confirmation.
4. Once the swap is complete, the system will credit the merchant in the order (settlement) currency.

How long is the instant swap exchange rate valid?

Once the user confirms the payment currency, the displayed instant swap exchange rate is valid for 10 minutes. If the user does not refresh the rate and continues to pay after the validity period expires, the payment will fail. If the payment fails due to an expired exchange rate, the paid amount will be refunded via the original route, with no fees charged.

Which currencies are currently supported?

The initial batch of supported instant swap payment currencies includes:

• USDT
• USDC

Additional mainstream digital assets will be supported over time based on user demand and market trends.

Do merchants bear any instant swap risk?

No. The entire instant swap process is handled by Gate Pay, and merchants are always credited in the required settlement currency for the order, unaffected by price fluctuations or the conversion process.

Does instant swap incur extra costs for merchants?

The instant swap exchange rate already includes the normal conversion costs. If a payment fails and is refunded due to system or exchange rate issues, neither users nor merchants will be charged any fees. Gate Pay covers the refund gas fees.

What backend changes should merchants be aware of?

No new or removed parameter fields; the credited amount in callback data remains in the swapped order currency.

1. Order Status Callbacks
   • waitAmountOnChain: For instant swap payments, the default returned value is 0.
   • doneAmountOnChain: For instant swap payments, the returned value is in the order currency unit.
2. Fund Transfer Callbacks
   • transferAmount: For instant swap payments, the returned value is in the order currency unit.

What is the process for handling instant swap payment failures?

1. The payer will receive a payment failure notification.

2. If the payment was initiated from a personal wallet address, wait for Gate Pay to refund the funds via the original route (usually within 30 minutes).

3. If the payment was initiated from an issuing address, the payer must proactively contact the merchant and provide their personal wallet address to Gate Pay for the refund.

Instant Swap API

Order and Transaction Timeliness

• Quote creation validity: Transactions must be executed within 8 seconds of creating a quote, otherwise an error will be returned.
• Quote exchange rate fluctuation: During the validity period, the transaction will be executed at the quoted exchange rate with no fluctuation.

Instant Swap Account and Fund Requirements

• Deduction method: All instant swap transactions use the payment account. Ensure the payment account has sufficient funds to deduct the quoted sellAmount.

Instant Swap Fees

The only fee for instant swap is the exchange rate (including slippage); there are no other fees.

• Service fee: No extra service fee for instant swap transactions; all costs are included in the price (exchange rate) returned by the quote. Thus, buyAmount and sellAmount directly reflect the actual credited and deducted amounts.
• How to get the exchange rate: The price field in the quote API response is the exchange rate.
• Is the exchange rate fixed: The rate is dynamically updated; you must request a new quote each time you initiate an instant swap. The interval between quoting and executing the transaction must not exceed 8 seconds.

Callback Notifications

• Is there asynchronous callback: Instant swap is a synchronous process and typically returns results in real time, so no asynchronous notification interface is provided.

Transaction Amount Limits

• Maximum/Minimum amount: The currency pair query API will return the maximum and minimum values.