BVNK Stablecoin Payments — a Mastercard Company
BVNK is enterprise stablecoin payment infrastructure: one API to accept stablecoins from customers, hold balances across fiat and digital currencies, and pay out to any wallet — with BVNK handling quotes, conversion, blockchain monitoring and gas. On August 3, 2026 Mastercard completed its acquisition of BVNK (up to $1.8B), becoming the first major card network to own stablecoin settlement rails. This guide covers the architecture, pay-in and payout transaction flows, the status model, and what the acquisition means.
Platform architecture
Integrations talk to a small set of API surfaces, all authenticated with Hawk-signed requests (an HMAC scheme over API key + secret) against sandbox (api.sandbox.bvnk.com) or production hosts:
| Surface | Endpoint family | Role |
|---|---|---|
| Payments | POST /api/v1/pay/summary | One endpoint, two directions: type: IN creates a pay-in with a locked quote and unique deposit address; type: OUT creates a payout. GET /api/v1/pay/{uuid} reads state. |
| Channels | POST /api/v2/channel | Permanent, re-usable deposit addresses — one per end-customer — converted at spot rate on arrival. |
| Payout helpers | /pay/validate · /pay/estimate · /pay/{uuid}/confirm | Address validation before money moves, indicative quotes refreshed every 30 s, and the confirm gate of the two-step payout. |
| Wallets | Wallets API | Fiat and stablecoin balances; each crypto wallet exposes addresses on its supported networks. Payouts debit amount + service fee + network fee. |
| Webhooks | Portal-configured HTTPS listeners | Status-change events with HMAC-SHA256 x-signature; ack with 200 in <10 s, dedupe on event ID, then re-fetch by UUID before acting. |
| Adjacent products | Virtual accounts · on-ramp · cards · embedded wallets | Fiat legs via SWIFT/SEPA virtual accounts, fiat→crypto on-ramping for customers, and card issuing — outside this guide's scope. |
Delivery models
BVNK supports a direct model (your business is BVNK's customer, one set of wallets) and an embedded model (you provision BVNK-backed customers and wallets for your own end-clients — the PSP-of-PSPs pattern). The API surface is the same; what changes is whose compliance details ride on each payment via complianceDetails.partyDetails (ORIGINATOR on pay-ins, BENEFICIARY on payouts — Travel Rule data).
Design stance: quotes are contracts. Every flow that moves value pins an exchange rate first — pay-in quotes lock at creation, payout quotes lock at creation (two-step) and hold for one hour, estimates refresh every 30 seconds until accepted. The platform never bears rate drift inside a confirmed flow.