Unsu PayA developer-first stablecoin payment gateway API. No registration, no account, no KYC, and no identity verification. Accept USDT, USDC, and USDS through hosted invoices across Ethereum, Base, and TRON.
Unsu gives your backend one stablecoin invoicing API and gives your customer a focused hosted checkout. Your wallet addresses are attached to the invoice; Unsu confirms the payment and reports the result.
Integrate using JSON over HTTPS, a server-side API key, and two payment endpoints. Safe retries use idempotency keys, invoices expire after 25 minutes, and payment confirmation stays server-authoritative.
API keys are stored as SHA-256 hashes, payment status is authenticated, and a blockchain transaction cannot be reused to settle another invoice. Lost plaintext API keys are rotated rather than recovered.
Security details →No. Unsu does not require account registration, KYC documents, or identity verification. Generate an API key, save it securely, and activate it through the 30-day subscription.
USDT and USDC on Ethereum, USDC and USDS on Base, and USDT on TRON.
No. Merchants provide their own wallet addresses when creating an invoice, and customers pay those invoice wallet addresses.
Your backend polls POST /v1/status every 15 seconds while expecting payment and stops when the invoice becomes PAID or EXPIRED.
The $39 subscription lasts 30 days and allows up to 500 paid invoices during that period.
No. Subscription allowances do not stack: activating the same key again replaces its current period with a new 30-day, 500-invoice allowance. If you need additional capacity for future use, generate and activate multiple API keys instead.
Each invoice and hosted checkout remains open for 25 minutes. Create a fresh invoice after expiration.
Unsu cannot recover the plaintext key because it is stored as a hash. Rotate the key to invalidate the old one and obtain a replacement.