Verifiable Purchase Mandate

Problem

Without verifiable evidence of authorization, an agent's payment is indistinguishable from an error, a hallucination, or a compromised key. A merchant cannot tell an approved purchase from an over-eager agent buying the wrong item, the network cannot attribute liability in a dispute, and a blanket pre-authorization that lets the agent spend freely gives away accountability. The system needs proof, checkable after the fact by parties who never saw the user, that a specific purchase matched a specific human authorization.

Solution

Represent the user's authorization as a signed mandate — a tamper-evident credential such as a signed JSON-LD object that records the conditions or the exact cart the user approved. For a real-time purchase the user signs a Cart Mandate over the finalised items and price; for a delegated task the user signs an Intent Mandate upfront stating the conditions under which the agent may buy, and the agent later produces a transaction that the mandate covers. The mandate travels with the payment so the merchant, the credential provider, and the network each verify the signature and confirm the charge falls within what was authorised, leaving a non-repudiable trail for dispute resolution.

When to use

• Agents complete purchases or payments where a merchant or network must trust that a human authorised the spend.
• Disputes and liability require after-the-fact proof of what the user actually approved.
• Both autonomous delegated buying and real-time human-approved checkout must be supported under one scheme.