An open protocol for securely initiating and completing payments that an AI agent makes on a user’s behalf. Google announced the Agent Payments Protocol (AP2) on September 16, 2025, with support from more than 60 payments and technology organizations. AP2 can be used as an extension of the Agent2Agent (A2A) protocol and the Model Context Protocol (MCP), and it is also compatible with the Universal Commerce Protocol (UCP). It is payment-agnostic, covering cards, real-time bank transfers, and emerging methods such as stablecoins.
Mandates and Verifiable Credentials
AP2 builds trust with mandates: tamper-proof, cryptographically signed digital contracts that serve as proof of a user’s instructions. Mandates are signed with verifiable credentials and create an audit trail from the original request through checkout and payment. That chain is designed to answer three questions that ordinary checkout flows assume a person is clicking buy: whether the user authorized the agent, whether the request matches the user’s intent, and who is accountable if a transaction is wrong or fraudulent.
- Intent mandate: Captures what the user asked the agent to do, including constraints such as price limits, timing, and other conditions.
- Cart or checkout mandate: Creates a secure, unchangeable record of the exact items and price once a cart is ready, or once pre-authorized conditions are met.
- Payment mandate: Links a payment method to that verified checkout so credential providers, networks, and merchant processors can confirm the agent is authorized to pay.
Human Present and Human Not Present Payments
When a person is present, the agent captures an intent mandate from the request, presents a cart, and the user approves a cart mandate before payment. When the user delegates a task, such as buying tickets the moment they go on sale, they sign a detailed intent mandate up front. The agent can then generate a cart mandate automatically once the stated conditions are met. In April 2026, Google released AP2 version 0.2 with updates for autonomous transactions, including Human Not Present payments, and donated the protocol to the FIDO Alliance so it can remain platform-agnostic and community-led. A related Verifiable Intent standard, developed with Mastercard and also donated to FIDO, creates a tamper-proof log of user-authorized agent actions.
Why AP2 Matters in Martech
Agentic commerce only works at scale if merchants, platforms, and payment providers can trust that an agent was allowed to buy. AP2 gives marketing and commerce teams a shared language for that consent, which helps reduce fragmentation across assistants and checkout surfaces. It also supports new buying patterns, such as monitoring price and availability and completing a purchase when conditions are met, while leaving a verifiable record for dispute and risk teams.
