Become the acquirer.
Not a hop to one.
A gateway forwards your REST call to someone else's acquirer. Payrithm composes the scheme message itself: a real Visa Base I, Mastercard BankNet, or Amex AEIPS ISO 8583 0100, or an ISO 20022 pacs.008, as the acquiring participant. One Stripe-shaped API to authorize, capture, void, and refund. Every call is composed and gated, fail-closed.
Pre-GA · taking design partners — see what runs today
illustrative · one acquiring posting, merchant & scheme reconciled to zero
# Payrithm composes the Visa Base I 0100 itself. The BIN routes the rail.
curl -X POST https://api.stringio.io/v1/authorize \
-H "Authorization: Bearer sk_live_••••" \
-H "Idempotency-Key: a1f3-trip-1184" \
-d '{ "merchant_id":"mer_2a9f4b7c", "amount_minor":4200,
"currency":"USD", "pan":"4929••••••••1729", "capture":false }'
→ 201 { "status": "requires_capture", "rail": "visa_base_i", "stan": "048217" }
→ then capture 5000 against the 4200 authorization:
→ 422 { "error": "guard_violation", "detail": "capture exceeds authorized amount" }
fail-closed · refuses, never clamps
Card schemes
Visa Base I · MC BankNet · Amex AEIPS
Account-to-account
SEPA CT/DD · FedNow · TCH RTP
Brazil · Pix
pacs.008 over the SPI
…and the seam to the rest
the 21-rail enum is closed; composers wired rail-by-rail
Eight rails composed today: 8 / 21 wired. Within a wire-family, a new scheme is a DE-profile, not a new codec.
One page, every method
Cards, wallets, net banking, mobile recharge and more on one checkout. The buyer chooses and pays in a single view, never bounced across pages.
One endpoint, routed for you
A single API reaches every method. Payrithm routes each transaction to the right partner or rail behind one merchant experience.
API-first, or hosted
Build against the API for full control, or drop in the hosted checkout to go live fast. Same engine underneath either way.
New methods, no re-integration
New payment methods and drop-in commerce plugins turn on in the same integration as they reach the market. You ship once.
Become the acquirer.
A card tap becomes a real scheme authorization composed as the acquiring participant.