Exchange Rate Lock & Price Calculation Breakdown

Understand the financial mechanics of the Hashpay confirmation screen: why specific numbers appear in the ledger, how fiat-to-crypto conversion formulas work, institutional spot price sourcing from Binance, and the 15-minute guaranteed rate lock.

Anatomy of the confirmation screen (Review before sending)

Before broadcasting funds to the blockchain, Hashpay presents the Confirmation Screen (*'Periksa sebelum mengirim — Semua angka di bawah sudah final'*). This step ensures 100% financial transparency before interacting with the decentralized ledger.

Hashpay Webview Exchange Rate and Calculation Screen — Figure 3: Confirmation Screen displaying detailed price calculation ledger and 15-minute locked exchange rate box

Why do these numbers appear? (Detailed ledger breakdown)

The ledger table itemizes every component of the checkout amount to eliminate hidden markups:

Nominal Pesanan (Order Amount) — The merchant's original invoice total in fiat currency (e.g. Rp 100.000,00).
Nominal Token (Token Amount) — The pure conversion of the fiat order amount divided by the locked spot rate (e.g. 5,531599 USDT). Formula: Token Amount = Fiat Amount / Locked Spot Rate (Rp 100.000 / Rp 18.077,95 = 5,531599 USDT).
Biaya Layanan (Service Fee / Gas Buffer) — The processing and miner gas allowance allocated for the transaction (e.g. 0,829657 USDT, indicated as *Ditanggung pembeli*).
Total Dikirim (Total Amount to Send) — The final exact crypto total the customer must transfer (e.g. 6,361256 USDT ≈ Rp 115.000).

Real-time spot price sourcing

Hashpay queries institutional real-time order books from tier-1 global cryptocurrency exchanges (such as Binance Spot) via backend Go microservices. This eliminates the inflated foreign exchange margins and retail conversion spreads typical of legacy payment gateways.

The 15-minute guaranteed rate lock mechanism

Crypto market prices fluctuate continuously. To protect the buyer from price swings while preparing their wallet, Hashpay freezes the conversion rate for 15 minutes (e.g. 1 USDT = Rp 18.077,95 · Kurs terkunci 01:00 · diperbarui otomatis):

Guaranteed Price Safety — Even if crypto market prices fluctuate while you are opening your wallet app or checking gas fees, your required crypto payment amount remains 100% unchanged.
Refresh Rate Button (Segarkan) — If the 15-minute timer lapses before you submit the transaction, the rate safely unlocks. You can tap Segarkan (Refresh Rate) to fetch a fresh 15-minute locked quotation matching current market rates without losing your order.
No Order Cancellation — Expired rate timers do not cancel your purchase; they simply update the crypto conversion quotation to reflect current spot market reality.

Proceeding to transfer

Clicking the purple Kirim [Amount] USDT button locks the quotation and generates a single-use blockchain deposit address and dynamic QR code.