Agent Payments Protocol (AP2)
A standard defining how an AI agent proves it has permission to pay, and how it executes that payment.
What is Agent Payments Protocol (AP2)?
AP2 is a standard defining how an AI agent proves it has a human's real permission to spend money, and how it then carries out that payment, on the person's behalf. In practice, it works like a cryptographically signed permission slip: before an agent can pay for something, it needs a tamper-proof record showing exactly what the user authorized, so a bank, card network, or merchant can later verify the payment was genuinely approved and not the agent acting on its own. This matters because payment networks need a reliable way to tell an authorized purchase from a rogue or hacked agent.
Why it matters
Google announced AP2 on September 16, 2025, as an open protocol built as an extension of the Agent2Agent (A2A) protocol, developed with more than 60 payments and technology partners including Mastercard, American Express, PayPal, Coinbase, Adyen, Salesforce, and Etsy. AP2's core mechanism is the "mandate": a cryptographically signed, non-repudiable digital contract, structured as an Intent Mandate (what the user wants) and a Cart Mandate (the specific items and final price), that creates a verifiable audit trail for every agent-initiated transaction. It is payment-method agnostic, with extensions published for card payments and for stablecoin/crypto payments (the latter developed with Coinbase and the Ethereum Foundation), and Google has positioned it as the payment-authorization layer underneath its broader Universal Commerce Protocol (UCP).