The Agent Payment Protocol Stack: Why Nobody Is Winning — And Everyone Is
The agent economy is developing a layered protocol stack rather than a single dominant player, with four key layers: Discovery (MCP), Identity (AP2/TAP), Checkout (ACP), and Settlement (x402/MPP). These protocols are designed to work together, enabling agents to discover services, authenticate spending, negotiate transactions, and settle payments seamlessly. Builders are advised to adopt these layers incrementally, starting with settlement and discovery, to cater to the evolving needs of agentic commerce. AI
IMPACT Explains the foundational infrastructure enabling agentic commerce and automated transactions.