The Agentic Commerce Protocol (ACP) and the Model Context Protocol (MCP) solve different problems, so comparing them is mostly a question of layers. MCP is a general way for an AI app to connect to outside tools and data. ACP defines how an AI agent and a merchant run a checkout and pass a payment credential. A merchant can even publish an ACP checkout through MCP.

The confusion is understandable. Both are open specifications, both show up in announcements about AI shopping, and payment companies now ship MCP servers of their own. A third name, Google’s Agent Payments Protocol (AP2), often appears in the same sentence. This guide sets out what each one standardizes, where they overlap, and what that means if you shop through an AI assistant or sell to one.

ACP, MCP and AP2 side by side

Agentic Commerce Protocol (ACP) Model Context Protocol (MCP) Agent Payments Protocol (AP2)
What it standardizes Checkout between a buyer’s AI agent, a business and its payment provider Connections between AI applications and external tools, data and workflows Proof that a user authorized an agent’s purchase
Who started it Stripe and OpenAI Anthropic, open-sourced November 25, 2024 Google, announced September 16, 2025
Payment-specific? Yes No Yes
How it is published Open source, Apache 2.0 license; the specification repository labels it beta Open-source standard with public documentation Open protocol; the AP2 site lists a v0.2 release and a donation to the FIDO Alliance
Relation to the others Checkout can be published through a traditional API or through MCP Can carry tools from any domain, including commerce Built as an extension for Agent2Agent (A2A) and Google’s Universal Commerce Protocol

The table describes what each project’s own documentation says. It is not a ranking: a merchant or AI platform can use more than one of them at once.

What MCP does

The MCP documentation describes it as an open-source standard for connecting AI applications to external systems, such as data sources, tools and workflows. It compares MCP to a USB-C port: one shared connector instead of a custom integration for every pair of app and service. Anthropic introduced and open-sourced MCP on November 25, 2024.

Nothing in that design is specific to money. An MCP server can expose a calendar, a code repository, a bank-data connector or a payment provider’s refund tool. That is why payment companies appear in MCP news. Our report on the Checkout.com MCP server covers one example aimed at developers, and our guide to Claude for personal finance lists connectors that read financial data.

What MCP does not do on its own is define a shopping cart, an order status, a merchant-of-record relationship or a way to hand a card credential to a seller. Those rules have to come from somewhere else. For checkout, that is the job ACP and similar commerce protocols take on.

What the Agentic Commerce Protocol does

The ACP site calls it an open standard for programmatic commerce flows between buyers, AI agents and businesses. Stripe and OpenAI developed it, and it is published under the Apache 2.0 license.

Four points from the ACP documentation matter most:

  • The business stays the merchant of record. It keeps control over which products can be sold, how they are presented and how orders are fulfilled.
  • The payment credential is passed as a token. ACP describes passing payment credentials from buyers to agents without exposing the underlying credentials. Stripe is the first compatible payment provider, with its Shared Payment Token.
  • It covers more than one-off physical orders. The site lists physical and digital goods, subscriptions and asynchronous purchases.
  • Implementing it does not list you automatically. OpenAI is the first AI platform to implement ACP, in ChatGPT, and each AI platform runs its own process for which businesses can take part.

OpenAI’s commerce documentation splits the work into an Agentic Checkout specification, a Delegated Payment specification and product feeds. The specification repository uses dated versions, starting with 2025-09-29; its April 17, 2026 version covers cart, feed, orders, authentication and MCP. How ChatGPT itself sells products has changed since launch, so check our ChatGPT Instant Checkout guide for the current buyer experience.

Where ACP and MCP meet

The overlap is deliberate. The ACP site says a business can publish its checkout configuration “with a traditional API or MCP.” In that setup, MCP is the connection between the AI app and the merchant’s systems, and ACP supplies the commerce rules that travel over it: what a checkout session contains, how it is updated and how payment is delegated.

So the two are not rivals for the same job. A merchant could expose an MCP server with no ACP checkout at all, for example to answer stock or order-status questions. A merchant could also implement ACP over a regular REST API without MCP. Choosing one does not rule out the other.

Where AP2 fits

AP2 addresses a different question: how a merchant, payment provider or bank can tell that the person really authorized what the agent is buying. Its documentation names three gaps when an agent starts a payment: authorization, authenticity and accountability. AP2 answers them with verifiable digital credentials, described in the specification as a Checkout Mandate and a Payment Mandate.

The AP2 site lays out the layers in a single line: build agents with any framework, “equip with MCP (or any tool),” collaborate through A2A, and use AP2 to secure payments. Its checkout counterpart is Google’s Universal Commerce Protocol rather than ACP. Our guides to what AP2 is and ACP vs UCP cover those pairings, and the agentic commerce protocols list tracks who supports what, including card-network programs and x402.

What this means if you shop through an AI assistant

You will not choose a protocol. You choose an app, a payment method and the limits you set. The protocols still shape a few things you can check:

  • Who sold you the item. Under ACP the business remains the merchant of record, so returns and order problems normally go to that business. Our guide on who pays when an AI agent buys the wrong thing covers refunds and chargebacks.
  • Whether an app can read or can pay. Connecting a bank or budgeting service through an MCP connector gives an assistant access to data. That is a different permission from letting an agent complete a purchase. Review both separately, and see our AI finance app privacy guide.
  • What limits apply. Spending controls sit in the AI app, the wallet and the card. Our AI agent spending limit guide lists them layer by layer.

What this means for a small business

If your store runs on a commerce platform, the platform may handle agent checkout for you; our Shopify agentic storefronts guide shows one example. If you build your own checkout, ACP is a specification your developers or payment provider implement, and the ACP site directs Stripe businesses to Stripe’s own agentic commerce documentation.

Publishing an MCP server does not, by itself, make products buyable inside ChatGPT or any other assistant. Each platform decides who can sell through it. Our no-code overview of AI agent payments for small shops compares the routes that exist today.

Questions about the Agentic Commerce Protocol and MCP

Is the Agentic Commerce Protocol built on MCP?

No. The Agentic Commerce Protocol is its own specification. Its site says a business can publish an ACP checkout through a traditional API or through MCP, so MCP is one way to carry ACP rather than its foundation.

Is MCP a payment protocol?

No. MCP connects AI applications to external tools and data in any field. Payment companies can offer MCP servers, but MCP itself does not define checkout, merchant-of-record roles or payment authorization.

What is the difference between the Agentic Commerce Protocol and AP2?

The Agentic Commerce Protocol coordinates a checkout between an agent and a business and passes a payment token. AP2 focuses on proving that the user authorized the purchase, using signed mandates, and is built as an extension for A2A and Google’s Universal Commerce Protocol.

Do shoppers need to set up ACP, MCP or AP2?

No. These protocols are implemented by businesses, payment providers and AI platforms. A shopper’s choices are the app, the payment method, the linked accounts and the spending limits.

How we checked this

This comparison uses the public ACP site and specification repository, OpenAI’s commerce documentation, the MCP documentation, Anthropic’s MCP announcement and the AP2 documentation. Facts checked October 10, 2026. It reports what the specifications and their publishers say; it is not a test of any implementation.

Sources

See the Agentic payments guides for related explainers.