## What is AP2?
**Agent Payments Protocol (AP2) is an open protocol for the emerging Agent
Economy.** It's designed to enable secure, reliable, and interoperable agent
commerce for developers, merchants, and the payments industry. The protocol is
available as an extension for the open-source
[Agent2Agent (A2A) protocol](https://a2a-protocol.org/) and
[Universal Commerce Protocol](https://ucp.dev/documentation/ucp-and-ap2/) with more integrations
in progress.
!!! abstract ""
Build agents with
**[{class="twemoji lg middle"} ADK](https://google.github.io/adk-docs/)**
_(or any framework)_, equip with
**[{class="twemoji lg middle"} MCP](https://modelcontextprotocol.io)**
_(or any tool)_, collaborate via
**[{class="twemoji sm middle"} A2A](https://a2a-protocol.org)**, and use
**{class="twemoji sm middle"} AP2** to secure payments with gen AI agents.
- :material-play-circle:{ .lg .middle } **Video** Intro in <7 min
---
- :material-file-document-outline:{ .lg .middle } **Read the docs**
---
[:octicons-arrow-right-24: AP2 v0.2 Release and FIDO Alliance Donation](https://blog.google/products-and-platforms/platforms/google-pay/agent-payments-protocol-fido-alliance/)
[:octicons-arrow-right-24: FIDO Alliance to Develop Standards for Trusted AI Agent Interactions](https://fidoalliance.org/fido-alliance-to-develop-standards-for-trusted-ai-agent-interactions/)
[:octicons-arrow-right-24: Agent Payments Protocol Announcement (9/16/2025)](https://cloud.google.com/blog/products/ai-machine-learning/announcing-agents-to-payments-ap2-protocol)
**Explore the detailed technical definition of the AP2 protocol**
[:octicons-arrow-right-24: Agent Payments Protocol Specification](ap2/specification.md)
[:octicons-arrow-right-24: AP2 and UCP integration guide](https://ucp.dev/documentation/ucp-and-ap2/)
---
## Why an Agent Payments Protocol is Needed
Today’s payment systems assume a human is directly clicking "buy" on a trusted
website. When an autonomous agent initiates a payment, this core assumption is
broken, leading to critical questions that current systems cannot answer:
- **Authorization:** How can we verify that a user gave an agent specific
authority for a particular purchase?
- **Authenticity:** How can a merchant be sure an agent's request accurately
reflects the user's true intent, without errors or AI "hallucinations"?
- **Accountability:** If a fraudulent or incorrect transaction occurs, who is
accountable—the user, the agent's developer, the merchant, the issuer, the
PSP, or the orchestration layer?
This ambiguity creates a crisis of trust that could significantly limit
adoption. Without a common protocol, we risk a fragmented ecosystem of
proprietary payment solutions, which would be confusing for users, expensive for
merchants, and difficult for financial institutions to manage. AP2 aims to
create a common language for any compliant agent to transact securely with any
compliant merchant globally.
---
## Core Principles and Goals
The Agent Payments Protocol is built on fundamental principles designed to
create a secure and fair ecosystem:
- **Openness and Interoperability:** As a non-proprietary, open extension for
A2A and MCP, AP2 fosters a competitive environment for innovation, broad
merchant reach, and user choice.
- **User Control and Privacy:** The user must always be in control. The
protocol is designed with privacy at its core, using a role-based
architecture to protect sensitive payment details and personal information.
- **Verifiable Intent, Not Inferred Action:** Trust in payments is anchored to
deterministic, non-repudiable proof of intent from the user, directly
addressing the risk of agent error or hallucination.
- **Clear Transaction Accountability:** AP2 provides a non-repudiable,
cryptographic audit trail for every transaction, aiding in dispute
resolution and building confidence for all participants.
- **Global and Future-Proof:** Designed as a global foundation, the initial
version supports common "pull" payment methods like credit and debit cards.
The roadmap includes e-wallets, "push" payments such as real-time bank
transfers (e.g., UPI and PIX), and digital currencies, recognizing that
many countries do not have real-time banking systems.
---
## Key Concept: Verifiable Digital Credentials (VDCs)
The Agent Payments Protocol engineers trust into the system using **verifiable
digital credentials (VDCs)**. VDCs are tamper-evident, cryptographically signed
digital objects that serve as the building blocks of a transaction. There are
two primary types of mandates, each existing in two stages:
- **Checkout Mandate**: Captures the reference to the specific items and
purchase details negotiated between the agent and the merchant, and is
**shared with the merchant**.
- **Open**: Captures the user's constraints and goals for the transaction
before a specific cart is finalized for autonomous execution.
- **Closed**: Captures the user's (or agent's) authorization for a specific,
finalized checkout.
- **Payment Mandate**: Authorizes a payment against a specific payment
instrument, and is **shared with the Credential Provider, Networks and the
Merchant Payment Processor**.
- **Open**: Captures the user's constraints on payment (e.g., budget,
allowed instruments) for autonomous execution.
- **Closed**: Captures the authorization for a specific transaction amount
bound to a finalized checkout.
These VDCs operate within a defined role-based architecture and are chained
together to provide a complete, verifiable audit trail for both human-present
and human-not-present transactions.
See more in the sample [Flows](ap2/flows.md).
## See it in action
- **Human Not Present Cards**
---
A sample demonstrating an autonomous transaction where the agent acts without human presence, using traditional card payments.
[:octicons-arrow-right-24: Go to sample](https://github.com/google-agentic-commerce/AP2/tree/main/code/samples/python/scenarios/a2a/human-not-present/cards/)
- **Human Not Present x402**
---
A sample demonstrating an autonomous transaction where the agent acts without human presence, using the x402 protocol for payments.
[:octicons-arrow-right-24: Go to sample](https://github.com/google-agentic-commerce/AP2/tree/main/code/samples/python/scenarios/a2a/human-not-present/x402/)
- **Digital Payment Credentials Android**
---
A sample demonstrating the use of digital payment credentials on an Android device.
[:octicons-arrow-right-24: Go to sample](https://github.com/google-agentic-commerce/AP2/tree/main/code/samples/android/scenarios/digital-payment-credentials/)
- **Human Present Cards**
---
A sample demonstrating a human-present transaction using traditional card payments.
[:octicons-arrow-right-24: Go to sample](https://github.com/google-agentic-commerce/AP2/tree/main/code/samples/python/scenarios/a2a/human-present/cards/)
---
## Get Started and Build with Us
The Agent Payments Protocol provides a mechanism for secure payments, and it's
part of a larger picture to unlock the full potential of agent-enabled commerce.
We actively seek your feedback and contributions to help build the future of
commerce.
Our public GitHub repo hosts the lastest version of AP2 specification, documentation and SDK. Standardization of the specification will continue within the Agentic Authentication Technical and Payments Technical Working Groups in FIDO.
You can get started today by:
- Downloading and running our **code samples**.
- **Experimenting with the protocol** and its different agent roles.
- Contributing your feedback and **code** to the public repository.
[Visit the GitHub Repository](https://github.com/google-agentic-commerce/AP2)
