What is Agent Payments Protocol (AP2)?

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Agent Payments Protocol (AP2) is an open protocol for securing payments performed by AI agents on behalf of users. Its core problem is authorization: when an autonomous agent initiates a transaction, merchants and payment participants need verifiable evidence of what the user approved rather than relying on the agent’s interpretation of intent.

AP2 addresses this with signed mandates and receipts. A checkout mandate captures what is being purchased, while a linked payment mandate captures the user’s authorization to pay. These artifacts can be presented and verified across the transaction flow and can provide evidence later if a payment is disputed. The protocol is designed to work alongside broader agent and commerce protocols rather than define catalog or checkout APIs itself.

Key ideas in AP2 include:

• Verifiable user intent instead of inferred permission from a conversational prompt.

• Explicit roles and verification responsibilities for agents, merchants, credential providers, and payment processors.

• Support for both human-present and autonomous, human-not-present payment flows.

• Cryptographic auditability so authorization and transaction evidence can be checked after the fact.

For commerce teams, AP2 highlights a fundamental difference between ordinary automation and autonomous purchasing: payment authority must be explicit, bounded, and auditable. An agent may help choose what to buy, but the payment layer still needs deterministic controls that prove the user authorized the specific commercial action.

Example: An agent may find a product autonomously, but the payment can proceed only when the signed mandate proves the user authorized the specific checkout and payment conditions being presented.