Agent Payments Protocol (AP2) – Agentic payments, trust, and the EU perspective

Journalist view: the five W's

Who: AI agent developers, merchants and retailers, payment providers and networks, consumers, and standards bodies (FIDO Alliance).

What: An open, community-driven protocol that standardizes how AI agents securely initiate and execute payments on behalf of users — covering authorization, authenticity, and accountability through cryptographic mandates and verifiable digital credentials.

When: Originally announced by Google in September 2025. Version 0.2 released April 2026, with donation to the FIDO Alliance for ongoing community governance and standardization.

Where: Designed as a global protocol. Works as an extension of the Agent2Agent (A2A) protocol and Model Context Protocol (MCP). Standardization continues within FIDO Alliance working groups.

Why: Today's payment systems assume a human clicks "buy." When autonomous agents initiate payments, core assumptions about authorization, authenticity, and accountability break — AP2 provides the trust framework to bridge that gap.

Status & availability (Europe)

As of May 2026, AP2 has been donated to the FIDO Alliance for open, community-led governance. Two new FIDO working groups — the Agentic Authentication Technical Working Group (chaired by CVS Health, Google, OpenAI; vice-chaired by Amazon, Google, Okta) and the Payments Technical Working Group (chaired by Mastercard and Visa) — are developing interoperable standards based on AP2 and Mastercard's Verifiable Intent framework.

The protocol is global by design. Specific implementations and availability in EU markets will depend on integration by payment providers and merchants operating in the region. AP2 v0.2 added "Human Not Present" payments for autonomous agent transactions and supports multiple payment types including cards, stablecoins, and real-time bank transfers.

Updated: 2026-05-18 · Source-first: official AP2 docs, FIDO Alliance, Google blog

How AP2 works: mandates and verifiable credentials

AP2 engineers trust into the system using Verifiable Digital Credentials (VDCs) — tamper-proof, cryptographically signed digital objects that serve as building blocks for every transaction. The protocol defines two primary mandate types:

Checkout Mandate

Captures the reference to specific items and purchase details negotiated between the agent and the merchant. Exists in two stages:

Open: captures the user's constraints and goals before a specific cart is finalized.
Closed: captures authorization for a specific, finalized checkout.

Payment Mandate

Authorizes payment against a specific instrument. Also exists in open and closed stages — from budget constraints to specific transaction amount bound to a finalized checkout.

These VDCs chain together to create a non-repudiable audit trail answering the three critical questions: authorization (did the user grant authority?), authenticity (does the request reflect true intent?), and accountability (who's responsible if something goes wrong?).

Two transaction modes

Human present: the user is in the loop — e.g. "Find me white running shoes." The agent searches, presents a cart, and the user signs a closed Cart Mandate before payment.

Human not present: the user delegates with conditions — e.g. "Buy concert tickets the moment they go on sale, max €120." The agent acts autonomously within the pre-signed Intent Mandate constraints.

Ecosystem: who benefits and how

For merchants & retailers

Keep your business logic and remain Merchant of Record. AP2 supports embedded checkout to preserve your custom experience while opening new agent-driven demand channels.

For AI platforms

Standardized APIs simplify onboarding. Choose your preferred agent frameworks and transports (A2A, MCP, custom APIs) while maintaining payment interoperability.

For payment providers

Open, modular payment handler design. Support for cards, stablecoins, real-time bank transfers, and digital currencies. Cryptographic proof of user consent built in.

For developers

Open-source SDK (Python, Go, Android), reference implementations, and code samples. Build integrations, contribute to the spec, implement extensions for complex patterns.

For consumers

Always in control. Privacy-first role-based architecture protects sensitive payment details. Verifiable intent ensures what you authorize is what gets executed.

For the EU ecosystem

AP2's roadmap includes real-time bank transfers (PSD2 context), push payments, and digital currencies — aligning with European payment infrastructure and regulation priorities.

Supporting organizations (60+)

A growing coalition of payment networks, technology companies, and financial institutions contributing to AP2's development:

Mastercard Visa PayPal American Express Adyen Revolut Coinbase Salesforce ServiceNow Intuit Shopee Etsy Adobe Dell 1Password Okta JCB Nexi Worldpay Checkout.com Airwallex DLocal Stripe (x402) MetaMask Deloitte PwC Accenture Forter Payoneer EBANX + many more

Where AP2 sits in the agentic commerce stack

AP2 doesn't operate in isolation. It's designed as an extension within a broader ecosystem of open standards for AI-agent interoperability:

A2A Protocol

Agent-to-Agent communication. Open standard (now Linux Foundation) for agents to discover, communicate, and delegate tasks across platforms.

a2a-protocol.org ↗

MCP

Model Context Protocol. Standardizes how agents connect to tools, APIs, and data sources. AP2 can be used as an MCP extension.

modelcontextprotocol.io ↗

UCP

Universal Commerce Protocol. End-to-end open commerce standard from discovery to purchase. AP2 integrates as the payments layer.

ucp.dev ↗

Verifiable Intent

Co-developed by Mastercard and Google. Tamper-proof log of user-authorized agent actions. Donated to FIDO alongside AP2.

Primary resources

What does AP2 mean for European commerce?

For payment service providers

AP2's modular payment handler design means PSPs can plug into agent-mediated commerce without rebuilding infrastructure. The protocol supports PSD2-compatible real-time bank transfers on its roadmap, alongside cards and digital currencies. European PSPs like Adyen, Nexi, and Worldpay are already contributing to the standard. The FIDO Alliance governance model aligns with the EU's preference for open, interoperable standards.

For e-commerce and retail

When purchasing can happen inside AI interfaces, conversion funnels compress. Merchants who prepare for AP2-compatible agent checkout can capture demand that begins in conversational AI surfaces — where much of the evaluative work may already be done before a consumer reaches a traditional storefront. AP2 preserves the Merchant of Record model, so brands retain control.

For developers and integrators

Start with the open-source SDK (Python and Go available now), run the reference scenarios, and experiment with both human-present and human-not-present flows. The protocol is designed to work with existing commerce infrastructure — treat it as an integration layer, not a platform replacement.

FAQ

Is AP2 only for Google?

No. AP2 was originally developed by Google but has been donated to the FIDO Alliance for community-led governance. It's designed as an open, vendor-agnostic protocol. Over 60 organizations — including Mastercard, Visa, PayPal, Adyen, Coinbase, Salesforce, and many others — are contributing to its development.

How does AP2 relate to A2A and MCP?

AP2 is designed as an extension of both the A2A protocol (agent-to-agent communication) and MCP (agent-to-tool connectivity). A2A handles how agents discover and talk to each other; MCP handles how agents access tools and data; AP2 handles the payments layer — how agents securely transact on behalf of users.

What payment types does AP2 support?

Currently, AP2 supports credit/debit cards and stablecoins/cryptocurrency (via the x402 extension with Coinbase). The roadmap includes e-wallets, real-time bank transfers (including European systems), and additional digital currency integrations.

When will AP2 be fully available in Europe?

AP2 is a protocol specification, not a deployed product — availability depends on adoption by payment providers and merchants operating in EU markets. European companies like Adyen, Nexi, Worldpay, and Revolut are already contributing partners. The FIDO Alliance's standardization process is underway.

Do I need to change my payment infrastructure?

Not necessarily. AP2 is designed to work with existing payment rails and infrastructure. It adds a trust and authorization layer for agent-initiated transactions rather than replacing existing systems. Think of it as an integration layer on top of your current setup.

What about PSD2 and European regulation?

AP2's design principles — user control, verifiable intent, accountability — align with PSD2's emphasis on strong customer authentication and transparent payment authorization. Specific regulatory compliance will be addressed as the FIDO Alliance standardization process progresses and European implementations emerge.

Contact

Want to discuss AP2 integration, agentic commerce strategy, or the European landscape? Send a message.