Google’s AP2 protocol enables secure AI agent payments with cryptographic proof

Google introduced the Agent Payments Protocol (AP2) on Tuesday, a standardization framework designed to enable AI agents to authorize and complete purchases while maintaining accountability and audit trails. The protocol addresses a fundamental challenge in AI-driven commerce: proving that automated transactions carry the same legitimacy as human-initiated purchases, with backing from over 60 companies including American Express, Mastercard, PayPal, and Coinbase.

How it works: AP2 uses cryptographically signed “mandates” that create tamper-evident records for each transaction phase.

• An intent mandate captures when a user requests an item, followed by a cart mandate that approves the final purchase basket.
• A third payment mandate signals to networks that an AI agent executed the order, creating a non-repudiable trail for fraud investigations and dispute resolution.
• The system works across different scenarios, from monitoring price thresholds to coordinating complex travel bookings with preset budgets.

Beyond traditional payments: While initially focused on card networks, AP2 was built to be payment-agnostic and already includes cryptocurrency integration.

• Google released an extension linking the protocol to the x402 crypto standard, developed with Coinbase, MetaMask, and the Ethereum Foundation.
• Future iterations will include real-time bank transfers and stablecoin support, bridging traditional card networks with instant payment systems.
• Coinbase published an explainer positioning the integration as a way to unify AI commerce with decentralized payments.

The competitive landscape: Major payment companies are simultaneously developing their own AI commerce solutions, highlighting industry-wide momentum.

• Mastercard is rolling out Agent Pay globally as part of a toolkit for agent-ready checkout flows.
• Visa opened its MCP server and released a no-code Agent Acceptance Toolkit for developers to integrate agents with Visa APIs.
• PayPal partnered with Perplexity in May to power “Buy With Pro” service, embedding agent-led purchases directly in browsers.

Why this matters: AP2’s biggest contribution is shifting proof of purchase from inference to verifiable, signed intent, giving merchants and issuers uniform handling of agent-driven requests.

• Each mandate documents what users authorized, what merchants promised, and what networks processed, potentially reducing false disputes.
• For risk teams, the protocol provides accountability that could help cut fraud without adding friction to legitimate transactions.
• The approach eliminates the need for merchants to negotiate bespoke integrations with different AI platforms.

The adoption test: Success hinges on developer uptake and merchant economics, with regulatory acceptance as the final hurdle.

• Google released full specifications, sample flows, and reference code on GitHub to lower barriers for pilot programs.
• Merchants will adopt if AP2 reduces fraud losses, prevents false declines, or increases conversion rates through richer agent-to-agent interactions.
• If mandates gain recognition as sufficient proof of authority, AI-driven transactions can scale through existing payment infrastructure without requiring custom agreements.