Card payments (SET Connect)
SET Merchant API · Live since 2026-11-09
A merchant with a SET Connect account takes card payments (and Stripe bank debits) through its embedded SET payment form, or through a hosted checkout it opens with its key. Each payment is a direct charge on the merchant's own Stripe account, with SET's fee as the application fee. SET records each payment in the merchant's SET records next to its stablecoin and bank payments.
Take a payment
POST /v1/card_checkouts with {amount, successUrl, cancelUrl, description?, reference?} returns a Stripe-hosted Checkout url for one USD payment (0.50 to 999,999.99) and the setFee. reference goes to Stripe's metadata only; SET does not store it. Send the same Idempotency-Key again and you get the same Checkout back.
Read payments
GET /v1/card_payments lists payments with state (pending, processing, succeeded, failed, canceled), amount, amountRefunded, setFee, setFeeRefunded, netBeforeStripeFees, disputeStatus, source (pay_form or checkout) and checkoutSession. GET /v1/card_payments/{pi_…} returns one. Events: card_payment.<state>, card_payment.refunded, card_payment.fee_refunded and card_payment.dispute.<status>.
Only payments SET started are recorded. The merchant's other Stripe business is its own and is never read into SET.
Refunds return SET's fee
POST /v1/card_payments/{pi_…}/refunds with {amount?, reason?} refunds what is left, or amount. SET's fee comes back in proportion. If the merchant refunds in its own Stripe Dashboard instead, SET returns the matching part of its fee afterwards. Either way, SET keeps its fee only on what was not refunded.
A lost dispute does not currently return SET's fee.
Monthly report
GET /v1/reports/monthly adds cardPayments per currency: payments, succeeded, gross, refunded, SET's fee, the fee refunded and net, net before Stripe's fees, disputes and disputes lost. Stripe's own processing fees are charged to the merchant's Stripe account and are not included.
Not yet included
- Card payments in journal entries.
- Paying an invoice by card.