x402 Payment Flow

This page explains the end-to-end x402 lifecycle implemented by ZenithPay.

Roles

• Buyer route: POST /pay (agent/operator entry point)
• Seller route: GET|POST /sell/agent-intel (x402 challenge + paid resource)
• Facilitator: OKX Payments API (/verify, /settle)

Sequence

1. Agent requests POST /pay with serviceUrl, maxAmount, and intent.
2. ZenithPay checks spend policy first (SpendPolicy.sol).
3. If required, ZenithPay performs exact-amount swap (OKB -> USDG).
4. ZenithPay calls seller route and receives x402 payment requirement (402).
5. ZenithPay builds payment payload and calls OKX /verify.
6. ZenithPay calls OKX /settle.
7. Seller route returns paid data.
8. ZenithPay writes ledger + returns transaction result.

Why this model

• policy gate is enforced before value movement
• settlement uses a standardized HTTP-native payment protocol
• buyer and seller concerns are clearly separated

Production endpoints

• Buyer: https://api.usezenithpay.xyz/pay
• Seller: https://api.usezenithpay.xyz/sell/agent-intel
• Facilitator: https://web3.okx.com/api/v6/x402/verify and /settle