ART-394 · OpenChainGraph

x402 Deferred-Scheme Handshake Validator

Cloudflare's deferred x402 scheme lets a 402 offer carry scheme:"deferred", an id, and a termsUrl; the client commits via an RFC 9421 HTTP Message Signature, and the validated id becomes the settlement reference for a subscription/daily/batch rollup. This tool validates the offer fields, the covered-component coverage of the signature (without performing cryptographic verification; that step reuses ART-129), and id continuity across a call sequence. Produces a §4 compliance_control OpenChainGraph artifact.

⚠ Compute-over-supplied-inputs only, nothing here initiates, routes, settles, or transmits a payment. Rollup/batch settlement arithmetic is ART-61's job, not this tool's. The scheme registry is a plugin surface and is not hard-coded here.

§4 OpenChainGraph · ART-394 x402 · deferred scheme Zero PII Client-Side · No Network

▸ Validate a deferred-scheme handshake

Paste the 402 offer JSON, the RFC 9421 covered-component list, and (optionally) prior settlement-reference ids for continuity checking. Everything runs locally.

Offer (JSON object: scheme, id, termsUrl)

Covered components (JSON array of strings, from Signature-Input)

Prior settlement-reference ids (JSON array, optional)