x402 Integration Kit
The x402 integration kit provides verifiable payment and settlement evidence for HTTP 402 machine-to-machine commerce flows.
What you get
- Four-layer adapter architecture: raw wire (A1), encoded payload (A2), semantic (B), mapped (C)
- Discriminated signed artifact unions for offers and receipts (JWS and EIP-712)
- 5-layer verification API with opt-in crypto
- Privacy-minimal receipt model
- Upstream-synced with x402 PR #935 (Offer/Receipt Extension)
Quick start
Terminal
pnpm add @peac/adapter-x402 @peac/protocol @peac/crypto
x402-verify.ts
import { verifyOffer, verifyReceipt } from '@peac/adapter-x402';
// Verify an x402 offer
const offerResult = verifyOffer(rawOffer);
// Verify an x402 receipt
const receiptResult = verifyReceipt(rawReceipt);
Key concepts
Transport limits: 8 KB header limit for x402/HTTP flows.
Verification layering: verifyOffer(), verifyReceipt(), and verifyOfferReceiptConsistency() provide incremental verification depth.
Closed-policy enums: Policy values use closed enumerations for deterministic matching.