Agentic Commerce T283 · T285 · T277 · T286 Discovery → Mandate → Settle → Audit A2A · AP2 · x402 · RFC 9421 Zero PII

Agentic Checkout, End-to-End

Pick a purchase scenario and watch an AI agent complete it: discover and validate the counterparty's A2A agent card, construct the Google AP2 checkout and payment mandates that carry the user's authority, settle over the x402 payment-required flow or a Visa Trusted Agent Protocol leg, and close with an RFC 9421-signed, hash-chained audit trail — the same four-stage chain any merchant or PSP must stand up before accepting agent-initiated payments in production.

Discovery
A2A v1.0
Agent card + extensions
Authorization
AP2 VDC
Checkout + payment mandates
Settlement Legs
2
x402 · Visa TAP
Signature Scheme
RFC 9421
HTTP Message Signatures
Mandate Schema
AP2 v1.0
@postoaklabs.com/agentic-checkout-v1
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Purchase Scenarios (Preset)
Checkout Parameters
Identity declared in the A2A agent card
What the agent is buying
Mandate + settlement currency
Max the user authorised — guardrail
AP2 distinguishes the two authority models
The rail the agent settles over
Authority window before re-authorisation
Deterministic · client-side · all four stages
Stage 01 · T283 A2A Agent Card

Discovery & Card Validation

Agent Card (synthetic, abridged)
Stage 02 · T285 Google AP2 Mandates

Checkout & Payment Mandate Construction

Payment Mandate (illustrative AP2 structure)
Stage 03 · T277 x402 Settlement

Payment-Required Flow Trace

#ActorActionDetailStatus
Stage 04 · RFC 9421 Signed Audit Trail

Signature Verification & Mandate Export

Hash-Chained Audit Trail
StageArtifactChained Hash (stub)
Policy Mandate Preview