The AP2 protocol
AP2, the Agent Payments Protocol, is an open protocol for payments made by AI agents. Google Cloud announced it on 16 September 2025. It answers a question card payments were not built for: did the buyer really authorise this agent to buy this?
Brand Design Ltd. in Varna has verified AP2 checkout mandates in its UCP checkout since 9 October 2026. Below is how AP2 works and exactly what we check.
What AP2 is
AP2 works through mandates: signed digital records of what the buyer allowed. A checkout mandate fixes what is being bought and for how much. A payment mandate travels with the payment and tells the payment side that an agent took part. Because the records are signed, the business, the bank and the buyer can check later who authorised what.
AP2 is available as an extension of A2A and UCP. Google has donated version 0.2 to the FIDO Alliance, which is developing standards for trusted interactions with AI agents.
How AP2 works in a purchase
The buyer authorises
The buyer confirms the purchase, and the confirmation is signed as a mandate that the agent carries.
The business checks before charging
Before it takes any money, the business checks the signatures and whether the amounts and lines match what the buyer approved.
The payment carries its own proof
A payment mandate can travel with the payment, so the bank also sees that an agent was involved.
AP2 at Brand Design Ltd.
Since 9 October 2026 our UCP checkout accepts AP2 checkout mandates. We sign the checkout, and before any charge we verify the mandate: the issuer’s signature, the holder’s signature and whether the amounts and lines match. The payment itself goes through Stripe.
Our UCP profile, which declares AP2
What this page does not claim
We verify the checkout mandate. Payment mandates and open mandates, which allow later purchases within set limits, are not accepted. Stripe processes our payments as usual and does not check AP2.
Official sources
Google Cloud’s announcement, 16 September 2025
Related pages
- UCP, ACP and AP2: the three protocols of agentic commerce
- The UCP protocol
- The ACP protocol
- Agentic commerce service
- B2A glossary: terms and protocols
- What is agentic commerce? A live test
Frequently asked questions
What is AP2?
AP2, the Agent Payments Protocol, is an open protocol for payments by AI agents, announced by Google Cloud. It uses signed mandates to prove what the buyer authorised.
What is an AP2 mandate?
A signed digital record of what the buyer allowed. The checkout mandate fixes the items and the amount; the payment mandate travels with the payment.
Is AP2 used in Bulgaria?
Yes. Brand Design Ltd. in Varna has verified AP2 checkout mandates in its UCP checkout since 9 October 2026.
Is AP2 the same as UCP?
No. UCP describes the purchase between the agent and the business. AP2 adds the proof of what the buyer authorised and works as an extension of UCP and A2A.