Integration guides
Build and operate the complete payment path from merchant registration to chain-confirmed fulfillment.
Use these guides when you are wiring a real product rather than inspecting one SDK function in isolation.
Start here
- Follow the complete payment flow to register a merchant, create a
PaymentRef, connect a wallet, settle x402, and verify finality. - Apply the production operations guide for secret storage, replay protection, recovery, reconciliation, and fulfillment policy.
- Use the API reference when you need exact function signatures and option fields.
Install once
Shellnpm install x402-paysdk
The package has three explicit trust-boundary entry points:
| Entry point | Runtime | Owns |
|---|---|---|
x402-paysdk/pay | Browser, app, wallet host | Offer verification, typed-data signing, payment submission, receipt and tx checks |
x402-paysdk/receive | Receiver app or trusted tool | PaymentRef creation, listing, and revocation |
x402-paysdk/merchant | Backend only | Merchant credentials, refs, orders, refunds, notify verification, and reconciliation |
Never import x402-paysdk/merchant into an untrusted browser. It is designed to hold merchant API and notify credentials.