Agent Payments Protocol (AP2) is an open protocol that enables AI agents to securely conduct payments on behalf of users, establishing trust between merchants, payment providers, and autonomous AI systems.
The Story Behind
When AI agents shop on behalf of users, merchants face a new problem: how do they verify the agent actually has permission to make a purchase? Payment systems were built around humans actively choosing to buy something. Autonomous agents operate differently, and existing infrastructure doesn’t account for that.
To solve this problem, Google introduced AP2 in September 2025 with over 60 partners, including Mastercard, PayPal, Coinbase, and Adyen. The AP2 works through cryptographically signed digital contracts called Mandates, which capture a user’s intent and authorization at each stage of a transaction. This gives merchants verifiable proof that an agent acted within the user’s permission.
AP2 is designed to work alongside existing agent communication standards, including Google’s own Agent2Agent (A2A) protocol and Anthropic’s Model Context Protocol (MCP), extending them specifically for payment scenarios. The framework supports multiple payment methods, from traditional credit cards to bank transfers and cryptocurrency transactions.
Benefits of AP2
Merchants get clearer accountability when something goes wrong, since AP2’s Mandates show exactly what was authorized. Payment providers can tell the difference between a human making a purchase and an AI agent doing it, which helps them assess risk more accurately. Users can trust their AI agents to stick to the rules they set, without worrying about overspending or unauthorized purchases.
For digital advertising specifically, AP2 changes how campaigns can connect to real purchases. As AI shopping agents become more common, advertisers need proof that a conversion was a real, authorized purchase, not a mistake or fraud. AP2 enables advertisers to verify those conversions. This also opens the door to new advertising ideas, for example: a user could set up rules letting an agent make repeat purchases on its own, which means brands could create offers built specifically for AI agents shopping on autopilot, not just one-time clicks.
Perspectives of Adoption
AP2 is still a young protocol, but it’s gaining traction fast. The ecosystem has already expanded to over 150 organizations integrating it into their systems. For the protocol to truly mature, seamless integration across different AI platforms, a wider network of financial institutions on board, and user understanding of cryptographically secured Mandates will be essential. If the current momentum continues, AP2 could become the standard for AI agent transactions.