What Is the Agentic Commerce Protocol (ACP)?

The Agentic Commerce Protocol (ACP) is an open, machine-readable standard that enables AI agents to shop on behalf of their users. Developed by OpenAI and Stripe, ACP creates the technical foundation for a ChatGPT conversation to end directly in a completed purchase — without a browser, without a checkout form, without any media break.

Background and Origins

ACP was jointly introduced by OpenAI and Stripe in September 2025. The launch was accompanied by a blog post from Stripe and an announcement on the OpenAI Developer Portal. The motivation was clear: ChatGPT already had over 700 million weekly users who were increasingly preparing purchase decisions via chat — but the actual purchase had to be completed on external websites.

This media break — from chat to browser, from agent to manual input — was inefficient and contradicted the promise of autonomous AI assistants. ACP closes this gap by defining a standardized way for an AI agent to handle the entire purchase process on behalf of the user.

The name "Agentic Commerce Protocol" directly references the overarching concept: Agentic Commerce — a commerce model in which AI agents shop autonomously.

The Vision: Commerce in Conversations

The central vision behind ACP is a paradigm shift: Commerce takes place where the user already is — in the chat, in the voice assistant, in the AI application. Instead of sending the user to a website, ACP brings the store to the user.

This fundamentally distinguishes ACP from previous approaches like affiliate links or chatbot recommendations, which ultimately always redirect to an external website. With ACP, the user stays in the chat. The agent takes on the role of the browser, the cart system, and the checkout form — but programmatically, via standardized APIs.

This vision has far-reaching implications for e-commerce as a whole: when the purchase process no longer takes place on a merchant's website, SEO strategies, conversion optimization, and the entire customer journey change fundamentally. Instead of user experience, agent experience becomes the success factor.

The Three Pillars in Detail

ACP defines three clearly separated layers that together cover the complete purchase process:

Product Feed Spec — The Data Foundation

The Product Feed Specification defines a standardized format in which merchants provide their products for AI agents. Unlike HTML pages designed for human eyes, the Product Feed is purely machine-readable. It contains structured fields for product name, description, prices, variants, availability, images, and checkout capability.

For merchants who already use Google Shopping Feeds, Facebook Catalogs, or other product data feeds, the structure is familiar. ACP merely standardizes which fields an AI agent needs and how they must be formatted.

Checkout API — The Transaction

The Checkout API is the heart of the protocol. Through four REST endpoints (CreateCheckout, UpdateCheckout, CompleteCheckout, CancelCheckout), an agent can programmatically create, modify, pay for, or cancel a cart. The merchant retains full control over prices, shipping costs, and order logic — the agent only displays to the user what the merchant's backend calculates.

Delegated Payment — The Payment

Payment processing is handled via tokenized credentials. The user stores their payment method once with the agent (e.g., in ChatGPT settings). During a purchase, the agent creates a SharedPaymentToken — a temporary, purpose-bound token that authorizes the payment without revealing the actual card data. The merchant redeems this token through their payment provider.

Merchant of Record: Merchants Retain Control

A crucial design principle of ACP: The merchant remains the Merchant of Record. This means:

• The merchant determines prices, not the agent
• The merchant calculates shipping costs and taxes
• The merchant handles fulfillment and customer service
• The order appears in the merchant's system like any other order

The agent is merely a channel — comparable to a marketplace or a social media shopping integration. The business relationship exists between merchant and customer, not between agent and customer.

Open Source and Governance

ACP is licensed under the Apache 2.0 License — one of the most permissive open-source licenses. This means:

• Anyone can implement the protocol, including commercially
• No license fees, no approval required
• Changes do not need to be contributed back (unlike GPL)
• The protocol can be embedded in proprietary software

Development takes place publicly on GitHub. Changes and extensions are proposed and discussed via RFCs (Request for Comments). Current governance lies with OpenAI and Stripe as Founding Maintainers, with the stated goal of transferring stewardship to a broader community in the long term.

Potential for Confusion: Other ACPs

The abbreviation "ACP" is used multiple times in the tech industry. To avoid confusion:

• Agentic Commerce Protocol (OpenAI/Stripe): Open standard for AI-powered commerce. This is the ACP discussed here.
• Agent Connect Protocol (Cisco): A protocol for contact centers that connects human service agents with software systems. No relation to AI agents or commerce.
• Agent Communication Protocol (IBM): A historical protocol for multi-agent systems in AI research. Not commerce-related.

In the context of Agentic Commerce and e-commerce, "ACP" always refers to the Agentic Commerce Protocol by OpenAI and Stripe.