Agentic commerce is what happens when an AI agent buys things for you: it finds the product, weighs the options, and completes the purchase, within limits you set, instead of you clicking through a checkout yourself. In 2026 it stopped being a demo and started becoming plumbing, with real protocols and the card networks moving in. Here is the stack in plain terms, and the half that gets forgotten.
Commerce performed by an AI agent acting for a person: it finds the product, decides, and completes the purchase within limits the person set. In 2026 it runs on emerging protocols, ACP for the checkout handshake and AP2 for payment consent, and it has two sides, the agent that pays and the merchant that gets paid.
ACP, the Agentic Commerce Protocol, is an open standard from OpenAI and Stripe for connecting a buyer's agent to a merchant, the checkout handshake. AP2, the Agent Payments Protocol, is the payment-consent layer: the person authorizes an agent once within set limits, and a token proves that consent without exposing banking data. They are different layers, and a full purchase uses both.
A sale only completes if the merchant can receive the money, so the merchant needs a real merchant account and machine-readable ways to transact: an MCP server or API, an OpenAPI spec, clear docs. Many individuals and no-code builders do not have this yet, which is the gap paas.build fills.
Publish an llms.txt, add structured data, expose an API and ideally an MCP endpoint, and make sure an agent can read a checkout without a full browser. paas.build gives an AI-built app a real merchant account the same day (no company, UK/EU/US) plus an MCP server and OpenAPI, so an agent can create a checkout and the builder gets paid, at a flat 3.9%.