What an HTTP 402 challenge is, and what it is not

2026-09-14 · Council of AI (CSOAI Ltd)

A 402 body is an offer that names the terms of a delivery; it is not a delivery, a settlement, or evidence that anyone paid.

GET /api/wrapper?id=usdc.e:arbitrum answers HTTP 402 with a JSON body: x402Version 2, one accepts entry with scheme exact, network eip155:8453, the USDC contract on Base as the asset, a payTo address, a timeout, and a description of the resource. That body is an offer. It names what would be delivered and on what terms. It is not a delivery, not a settlement, and not evidence that anyone has ever paid. The amount appears inside the challenge, which is the place a reader should take it from. The door-conformance report probes this door among others and records, row by row, that the challenge shape conformed while fulfillment stayed UNMEASURED, because no payment was exercised. The resource description itself sets the scope of what sits behind the offer: a ratio, not a rate, a grade or a reserve attestation. The /wrappers/ page describes a free preview of the same card.

How to verify: fetch the artifacts listed above yourself, and check a signed card against the published key at https://councilof.ai/gspc-verify/.

Measurement, not certification. Not a grade, endorsement or legal finding.