AP2, the Agent Payments Protocol, is an open protocol from Google — developed with more than 60 payments and technology partners — for letting AI agents buy things on a user’s behalf safely. As shopping assistants and autonomous agents start initiating real transactions, AP2 defines how merchants, payment networks and users can verify that an agent is acting with genuine authorization. The specification and reference code live on GitHub, where the project has about 3,200 stars and is actively evolving in 2026.
AP2 builds on the Agent2Agent (A2A) protocol and the Model Context Protocol, adding a payments layer based on cryptographically signed mandates. An Intent Mandate captures what the user asked the agent to do, a Cart Mandate locks in the exact items and price the user approved, and a Payment Mandate carries the authorization to the payment network — creating an auditable chain from instruction to settlement. The design supports both human-present purchases, where the user confirms in real time, and delegated scenarios such as an agent buying the moment an item drops in price or restocks. It is payment-method agnostic, covering cards, bank transfers and even stablecoins through extensions, and it defines roles and accountability so disputes have clear evidence.
AP2 is an open standard: the specification and code are free and open source under the Apache-2.0 license, with no fees to implement or adopt it.
AP2 is for payment providers, merchants, agent platforms and developers building agentic commerce who need a shared, trustworthy way for AI agents to transact with provable user consent.