Verified facts

An AI shopping agent reads a product page and has to trust what it says. A material, a size or a certification is only as good as the source behind it, and the agent cannot see that source. A verified fact carries it: the fact names its product, its evidence and the issuer who stands behind it, so an agent can check the claim instead of guessing.

• The exact product and variant it describes, never a match on the title alone.
• The attribute and its typed value, with units.
• The evidence: a reference to the source, its digest, the method used and the date it was observed.
• Its trust class: merchant-asserted, source-corroborated, independently verified, or unknown.
• Its signed issuer, and when it was issued, last checked and expires.

An agent confirms the issuer, the signature, the product the fact names, and that the fact has not expired, been revoked or been superseded. A fact that fails a check is rejected with its reason: unsupported version, subject mismatch, invalid signature, source unavailable, expired, revoked, permission denied or status unknown. An unknown fact is never shown as verified.

A signature shows who issued a fact, not that it is true. The evidence is what an agent weighs.

The format is designed to travel two ways: through a neutral API, and, when both sides support it, as a UCP extension under the proposed name com.arbling.shopping.verified_facts. It sits alongside a store's existing commerce profile, including the one Shopify manages, and never replaces it.

Agencies prepare and maintain the evidence for the stores they serve, with each client's authorization. The store's own price, stock and payment terms stay the store's to set.

Version 0.1 is an open draft, published for stores, agencies and agent developers to review and build against. A fact describes a product; the price, stock and terms at checkout come from the store's own checkout.