Google AP2 Gives AI Purchases a Signed Paper Trail

Google introduced the Agent Payments Protocol, or AP2, on September 16 to address a basic problem in automated shopping: how can a merchant establish that an AI agent has permission to spend a customer’s money?

The announcement describes an open, payment-agnostic framework developed with more than 60 participating organizations. AP2 can work alongside Google’s Agent2Agent protocol and the Model Context Protocol. It is intended to connect a user’s instructions with the eventual shopping cart and payment.

What the customer actually approved

AP2 uses cryptographically signed records called mandates. An Intent Mandate captures the customer’s request and any spending conditions. A Cart Mandate records the specific purchase, including the items and price.

For a shopper who remains present, the agent can propose a cart and ask for approval before buying. In a delegated task, the user sets conditions in advance, such as a maximum price and an allowed purchase window. The agent may then create a cart within those conditions.

The useful distinction is between an agent’s interpretation of a request and evidence of permission. A conversational instruction can be ambiguous. A signed record gives the merchant and payment provider something more precise to check when accepting a transaction or investigating a dispute.

That record does not, by itself, resolve every disagreement about delivery, refunds or fraud. Google presents AP2 as a foundation that operates alongside payment rules and industry standards.

Cards and crypto share an authorization problem

The protocol is designed for several payment methods, including cards, real-time bank transfers and stablecoins. Google also announced an A2A x402 extension with organizations including Coinbase, the Ethereum Foundation and MetaMask for agent-based crypto payments.

Supporting multiple methods matters because permission to buy and movement of money are different parts of a transaction. An agent might have a valid instruction while still lacking an accepted payment method at the merchant.

For developers, the immediate deliverables are a public specification, documentation and reference implementations. Participation in the announcement does not mean every named company has deployed an AP2 checkout.