Putting it all together

Pay for an x402 resource with a mandate (no per-payment approval):

1. Register once; store agent_id, token, jwt. Refresh the jwt with /refresh when it expires.
2. Create a mandate and have the user open authorizationUrl to link the agent and sign. Poll Get mandate by ID until status is signed.
3. Call the third-party API. On HTTP 402, take the fields from accepts[0].
4. Call GET /api/mandates/eligible with host, amount, currency to pick a mandateId.
5. Call POST /api/payment/x402V3Payment (or POST /api/v2/payment/x402-payment for x402 v2 requirements).
6. Send the returned xPaymentB64 as X-Payment and retry the original request.

Without a mandate, use POST /api/payment/x402V1Payment; if it returns need_approval, show approvalUrl and retry with approvalId.

Send funds out:

• POST /api/payouts (with mandateId for automatic approval), then poll GET /api/payouts/{payoutId} until displayStatus is completed, failed, rejected, or expired.

Receive funds:

• Create a link via POST /api/payment-links (maxUses: 1 per order, externalId = your order ID).
• Share url (agents, x402) or checkoutUrl (people).
• Poll GET /api/payment-links/{linkId}/payments and fulfil only when settlementStatus is settled. There are no webhooks.
• Refund with POST /api/payment-links/refunds/initiate and pay the returned refundUrl.