Agent Payments Protocol (AP2)
Google's open-source framework for building secure, interoperable AI-driven payment systems. Enables agent-to-agent transactions across platforms.
What is AP2?
The Agent Payments Protocol (AP2) is Google's open-source specification for enabling secure, AI-driven payment transactions. Released under the Apache 2.0 licence, AP2 provides a flexible, protocol-agnostic framework that allows AI agents to autonomously handle payments across diverse platforms and development environments.
Unlike traditional payment flows that require human intervention, AP2 enables agent-to-agent (A2A) transactions—where AI agents can negotiate, authorise, and complete payments on behalf of users without manual oversight at each step.
AP2 is designed with interoperability at its core, supporting integration with multiple AI development tools and not tying businesses to a specific technology stack. This makes it particularly suitable for enterprises building custom AI commerce solutions.
Key Features
Agent-to-Agent Transactions
Enables AI agents to transact directly with each other, automating complex multi-party commerce scenarios.
Protocol Agnostic
Not tied to specific development tools or frameworks—integrate with any AI platform or tech stack.
Interoperability First
Designed for cross-platform compatibility, allowing agents from different systems to transact seamlessly.
Flexible Authentication
Supports Google API Key (dev) and Vertex AI (production) authentication, with extensibility for other providers.
Python Native
Primary implementation in Python 3.10+ with comprehensive type definitions and modern tooling support.
Open Source
Apache 2.0 licensed with active GitHub repository, enabling community contributions and transparency.
Technical Requirements
Prerequisites
- Python3.10 or higher
- Package Manageruv (recommended)
- AuthenticationGoogle API Key or Vertex AI credentials
Authentication Options
Google API Key
Recommended for development and testing environments. Quick setup with environment variable configuration.
Vertex AI
Recommended for production deployments. Enterprise-grade authentication with full GCP integration.
How AP2 Transactions Work
AP2 enables autonomous payment flows between AI agents. Here's a typical transaction sequence:
Agent Discovery
User's AI agent identifies a merchant or service provider that supports AP2 transactions.
Transaction Initiation
The buyer agent communicates transaction intent to the seller agent, including product details and payment parameters.
Agent Negotiation
Agents exchange structured data about pricing, terms, delivery options—potentially adjusting based on programmatic rules.
User Authorisation
The buyer agent requests user confirmation for the transaction, presenting terms in a clear, understandable format.
Payment Execution
Upon approval, the buyer agent securely transmits payment credentials through AP2's secure channel to the seller agent.
Transaction Verification
The seller agent processes payment, confirms receipt, and provides transaction confirmation to the buyer agent.
Fulfilment & Tracking
Both agents coordinate fulfilment, with the buyer agent keeping the user informed about order status and delivery.
Use Cases for AP2
Multi-Agent Marketplaces
Enable platforms where multiple AI agents represent different vendors, negotiating and transacting autonomously on behalf of their users.
Enterprise Procurement
Automate B2B purchasing workflows where procurement agents negotiate with supplier agents based on pre-approved budgets and criteria.
Subscription Management
AI agents can autonomously manage recurring subscriptions, handling renewals, upgrades, and cancellations based on user preferences.
Dynamic Pricing Negotiations
Agents can engage in real-time price negotiations, adjusting based on inventory levels, demand, and customer loyalty.
Why Choose AP2
Platform Independence
Not locked to Google services—integrate with any AI platform or cloud provider.
Enterprise Ready
Built with production scalability and security in mind, suitable for high-volume commerce.
Advanced A2A Capability
Supports sophisticated multi-agent transaction scenarios beyond simple checkout flows.
Active Development
Backed by Google with ongoing improvements and community contributions.
Flexible Integration
Works with diverse AI development kits and frameworks, including ADK and Gemini.
Transparent Governance
Open-source with clear documentation and sample implementations on GitHub.
AP2 vs ACP
See how AP2 compares to OpenAI and Stripe's Agentic Commerce Protocol.
Ready to Implement AP2?
Get technical guidance on integrating the Agent Payments Protocol into your commerce platform.