Payments / Marketplace

Reference build: crypto checkout and payouts

A marketplace both collects from buyers and pays sellers. This build uses the payment primitives for the inbound half and the payout primitives for the outbound half, reconciled through signed webhooks.

The challenge

Collecting and disbursing crypto usually means a processor for one side and custody tooling for the other. The goal is to run both directions on one balance with consistent, verifiable event delivery.

Primitives used
  • Invoices / checkoutC2
  • Mass payout / settlementC2
  • Build / sign / broadcastC2
  • Webhook (HMAC) deliveryC1

Collect with invoices

Create an invoice per order and present the hosted checkout. Underpayment, overpayment and confirmations are tracked for you.

Reconcile with signed webhooks

Settlement fires an HMAC-signed, idempotent webhook. Verify the signature and mark the order paid — duplicate deliveries won't double-credit.

Disburse with mass payout

Pay sellers in a batch from the same balance, broadcasting transfers and tracking each to confirmation.

What the build delivers

  • Inbound collection and outbound payouts on one balance
  • Idempotent, signed webhooks so reconciliation can't double-count
  • No separate processor and custody contracts to maintain

Frequently asked

How is double-crediting prevented?

Webhook delivery is idempotent and signed; a duplicate settlement event is recognized and ignored.

Can collection and payout share funds?

Yes — both run against one balance, so collected funds can settle outbound payouts.

Top up, get a key, ship.

Self-serve. Pay in crypto or card. Metered by credits — heavy primitives cost more, simple ones are cheap.

Get API key