AP2, A2A, and MCP
The Agent Payments Protocol (AP2) is designed to be an extension of the Agent-to-Agent (A2A) protocol and work in concert with Model-Context Protocol (MCP).
!!! abstract "Communication disambiguation"
- MCP: Agents communicate with data (APIs)
- A2A: Agents communicate with other Agents (tasks and messages)
- AP2: Agents communicate about payments (mandates)
AP2 + A2A for Inter-Agent Communication for Payments
The Agent Payments Protocol (AP2) is designed as an optional extension for open-source protocols like A2A and MCP, allowing developers to build upon existing work to create a secure and reliable framework for AI-driven payments.
- AP2 is required to standardize the communication payments details like mandates.
- A2A is required to standardize intra-agent communication, as soon as you have more than one agent you need A2A.
AP2 directly extends the Agent-to-Agent (A2A) protocol for multi-agent payments transactions between actors like Shopping Agents, Merchants, and Credentials Providers.
AP2 + MCP for External Resource Interaction
MCP is a protocol that standardizes how AI models and agents connect to and interact with external resources like tools, APIs, and data sources.
Developers can implement their own tools to integrate with providers.
We are working on MCP servers for AP2.
In essence, A2A and MCP provide the foundational communication and interaction layers for AI agents, enabling them to connect and perform tasks. AP2 builds upon these layers by adding a specialized, secure payments extension, addressing the unique challenges of authorization, authenticity, and accountability in AI-driven payments. This allows agents to confidently browse, negotiate, buy, and sell on behalf of users by establishing verifiable proof of intent and clear accountability within transactions.