ACP: The Commerce Layer for AI Agents

Part 1 of our three-part series on the agentic commerce stack, written for the directors of businesses that sell online and need to know what changes when the customer is an AI agent. This instalment covers ACP, the checkout layer. Part 2 covers AP2, the authorisation layer. Part 3 covers x402, the settlement layer.

In one paragraph

Since September 2025, people have been buying products inside ChatGPT conversations. The Agentic Commerce Protocol (ACP), an open standard co-developed by Stripe and OpenAI, is what makes that possible: it lets an AI agent run a checkout with a merchant while the merchant stays merchant of record, keeps its customer relationship, and never hands card details to the agent. For a retailer or marketplace, ACP is a new sales channel that can be switched on with modest engineering, and a channel that McKinsey forecasts could carry $3–5 trillion of global retail revenue by 2030.

Why checkout had to change

Online checkout was designed for a person with a browser: pages, forms, card fields in secure frames, redirects. An AI agent cannot click through that. It has no browser session, it does not retain form context, and it must never be handed raw card numbers.

The gap is commercial as much as technical. Bain estimates that 15–25% of US ecommerce will flow through AI agents by 2030. Merchants need a way to sell through agents without rebuilding their commerce stack, and agents need a programmatic checkout that keeps credentials out of their hands. ACP is that interface.

How it works, for a non-engineer

ACP defines four participants and keeps their responsibilities separate:

• The buyer talks to an AI agent, reviews options and authorises the purchase. They never give the agent their card. Instead their payment provider issues a scoped token.
• The agent finds products, opens a checkout with the merchant, shows totals and delivery options, collects the buyer's authorisation and completes the purchase. It never becomes the merchant of record.
• The merchant keeps full control. In Stripe's words: "you maintain your customer relationships as the merchant of record, retaining control over which products can be sold, how they're presented, how transactions are processed, and how orders are fulfilled." Pricing, stock, fraud decisions and fulfilment stay with you.
• The payment provider (initially Stripe) issues a SharedPaymentToken: a token limited to one merchant, one maximum amount and a short time window, used once. It contains no real card data. Stripe's fraud tooling still scores the transaction, so an agent-originated order gets the same accept or decline decision as any other.

The checkout itself runs over a handful of standard web endpoints (create, update, complete, cancel) specified by the protocol, with order updates sent back to the agent afterwards so the buyer can be told when the parcel ships.

What it costs to adopt

For a merchant already on Stripe, agentic checkout can be enabled with minimal code changes. For everyone else, ACP is an open specification: the checkout endpoints can be implemented on any stack, or exposed as a Model Context Protocol (MCP) server for AI-native architectures. Payment providers beyond Stripe can participate through the Delegated Payment Specification; direct integration requires PCI DSS Level 1 or the use of network tokens.

The larger cost is usually not the endpoints. It is product data. An agent can only sell what it can read: accurate titles, attributes, availability, delivery options and returns terms. Businesses whose catalogue lives in several systems that disagree will find that the integration work is the prerequisite.

Who is already doing it

ACP launched on 29 September 2025 with Instant Checkout in ChatGPT for US users, starting with Etsy merchants and expanding to Shopify. Payment details are, as OpenAI puts it, "processed securely by trusted payments partners, and not stored by OpenAI."

Direct early adopters include URBN (Anthropologie, Free People, Urban Outfitters), Coach, Kate Spade, Revolve and Ashley Furniture. Platform partners include Etsy, Shopify, Wix, WooCommerce, BigCommerce, Squarespace and commercetools. PwC has a consulting partnership to help larger enterprises structure product data and pilot integrations.

Where ACP sits in the stack

ACP is the commerce layer of three complementary protocols. As Orium's analysis puts it, "ACP, AP2, and x402 are not direct competitors so much as layers in an emerging agentic commerce stack."

ACP is deliberately the path of least resistance: it adapts existing card infrastructure rather than replacing it, which is why it was deployable to Stripe's merchants on day one.

What this means for your business

• A new channel with measurable attribution. Orders arriving through an agent are tagged as such, so you can see what the channel is worth before investing further.
• Control stays with you. Which products, at what price, on what terms, with your fraud rules. Nothing about ACP obliges you to discount or to hand the customer relationship to a platform.
• Product data becomes a revenue asset. Businesses with clean, complete catalogue data will be recommended by agents; those without will be invisible to them.
• Payment risk does not increase. Scoped tokens and existing fraud scoring mean an agent order carries no more credential exposure than a web order.

What to do now

1. Ask your platform or payment provider when agentic checkout is available to you and what it requires.
2. Audit your product data for completeness and consistency across every system that holds it.
3. Decide the commercial terms for the channel: which ranges, which prices, which delivery options.
4. Instrument attribution so agent-originated orders are visible in your reporting from the first one.

How Hexploits helps

We build the integrations that give an agent one truthful view of stock, price and order status, and the agentic workflows and governance that keep an automated channel under control. For ecommerce and retail businesses we have written up the pressures we see most often on our sector page.

Request a proposal or talk to an engineer. You will have a written scope and an indicative price within two working days.

Continue to Part 2: AP2, the authorisation layer, or Part 3: x402, the settlement layer.