Definition
The Agentic Commerce Protocol (ACP) is an open standard, introduced by OpenAI and Stripe, that defines how AI agents and merchants exchange the information needed to complete a purchase inside a conversational surface. It powers experiences like in-ChatGPT checkout, where a user can buy from a merchant without leaving the chat, while payment and order details flow through a standardized, secure interface.
ACP is one of several protocols forming the plumbing of agentic commerce. It sits alongside the Model Context Protocol (MCP), which gives agents secure access to business data and tools, and broader efforts such as Google's Universal Commerce Protocol and the Agent Payments Protocol (AP2) for verifiable, user-authorized settlement. Together these standards aim to let agents discover products, build a cart, and complete a delegated checkout with explicit user consent.
The protocol matters because it turns AI shopping from recommendation into transaction. Rather than sending a user to a merchant's site, a compliant agent can pass structured order and payment data to the merchant and confirm the purchase in-context. For merchants, supporting ACP means exposing machine-readable product and checkout data and integrating with the payment flow.
For GEO and ecommerce teams, ACP is the transactional endpoint of an agent experience optimization strategy: being cited and recommended is necessary, but protocol support is what lets an agent actually buy from you. As adoption grows, protocol compatibility and clean structured data become competitive requirements rather than experiments. Our ChatGPT shopping usage data shows how quickly in-chat checkout is scaling.
Examples of Agentic Commerce Protocol (ACP)
- A shopper completes a purchase from a merchant directly inside ChatGPT, with order and payment data passed through ACP rather than a redirect to the store.
- A retailer integrates ACP and Stripe so AI agents can finalize checkout in-conversation while the merchant retains the order relationship.
- A platform team evaluates ACP, MCP, and AP2 together to support discovery, data access, and authorized payment for agent-driven transactions.
- A GEO team tests agentic commerce protocol support by confirming whether AI shopping agents can actually complete a delegated checkout with their products, not just recommend them.
