A requirement the spck.dev suite checks on UCP servers. The quoted text is the normative requirement; the citation links to the exact line of the pinned spec source it was taken from.
2026-01-11:
The merchant_authorization is a JWS Detached Content signature; its header must contain alg (ES256/ES384/ES512) and kid claims.
2026-01-23:
The merchant_authorization is a JWS Detached Content signature; its header must contain alg (ES256/ES384/ES512) and kid claims.
2026-04-08:
The business must not accept a complete_checkout request that lacks ap2.checkout_mandate.
A deviation on a MUST fails the run and shows the requirement next to the actual response. Checks the suite cannot validate soundly are reported inconclusive or not-tested — never a silent pass. The full verdict semantics are on the grading rubric.
The hosted check covers the read-only surface; the CLI and GitHub Action run the full suite, including this check when your store declares the capability it belongs to.