Agent Payments Protocol (AP2)
Definition
The Agent Payments Protocol, or AP2, is an open protocol developed by Google to solve a specific problem in agentic commerce: how does a merchant or a bank know that an AI agent genuinely has a person's permission to spend their money, and within what limits? AP2 defines signed mandates: structured, cryptographically verifiable records of what the person authorized, such as a maximum amount, a category of purchase, or a time window.
On April 28, 2026, Google donated AP2 to the FIDO Alliance jointly with Mastercard, moving it from a Google-led initiative to a vendor-neutral standard governed the same way as FIDO's existing passwordless authentication specifications. The goal is for AP2 to work across different AI platforms and payment networks rather than being tied to one company's ecosystem.
AP2 complements rather than replaces purchase-level protocols like ACP and UCP: those standardize how the purchase and checkout flow works, while AP2 standardizes the authorization step underneath it, the proof that the agent is allowed to pay at all. Payment networks implement compatible mechanisms, such as Agentic Tokens, to carry that authorization through to an actual transaction.
This authorization layer is also where European regulation becomes directly relevant: delegating payment authority to an agent raises questions under PSD2/PSD3 about strong customer authentication, which is why mandates and their verifiability matter as much to regulators as to merchants. See the Agentic Commerce entry for the wider context.
Examples
A person sets up a travel-booking agent with a mandate authorizing it to book flights up to 500 EUR without further confirmation, but requiring explicit approval above that amount. AP2 lets the airline's payment system verify that mandate before accepting the agent's payment.
A bank receives a payment request from an agent claiming to act for one of its customers. Because the request carries an AP2 mandate signed by the customer's own device, the bank can distinguish it from a fraudulent attempt to impersonate an agent.
Frequently Asked Questions
What problem does AP2 solve that ACP and UCP do not?
ACP and UCP standardize how a purchase and checkout flow between a merchant and an AI agent. AP2 standardizes the step before that: proving the agent actually has the person's authorization to pay, and under what limits.
Who governs AP2 today?
Google developed AP2, then donated it to the FIDO Alliance on April 28, 2026, jointly with Mastercard, making it a vendor-neutral standard rather than a Google-only initiative.
What is a mandate in AP2?
A mandate is a signed, verifiable record of what a person authorized an agent to do, such as a maximum amount, a category of purchase, or a time window, that a merchant or bank can check before accepting an agent-initiated payment.
How does AP2 relate to European payment regulation?
Delegating payment authority to an AI agent raises questions under PSD2/PSD3 around strong customer authentication. AP2's signed mandates are designed to give regulators and banks a verifiable trail of what the person actually authorized, which is central to that regulatory conversation.
