Trusted Agent Protocol verification checklist

What the protocol establishes

Visa's Trusted Agent Protocol helps a merchant recognize an approved agent through signed, time-bound request evidence. Identity recognition is one input to a payment decision, not the complete authorization decision.

Five checks before execution

1. Verify the HTTP message signature against a trusted key.
2. Check created, expiry, nonce, authority and path binding.
3. Confirm the signature tag matches browsing or payment intent.
4. Evaluate amount, currency, merchant and user-approved limits.
5. Store and atomically reject replayed transaction identifiers.

The gap MandateShield closes

A recognized agent can still submit a transaction outside the specific amount, merchant or time window the user approved.

MandateShield normalizes execution facts and returns a deterministic decision with exact findings and a tamper-evident receipt. It complements protocol-native signature verification; it does not replace it.