The Agentic Commerce Protocol (ACP) is an open standard developed by OpenAI that defines the APIs and data flows for completing a purchase within a conversational AI agent like ChatGPT. 

Agentic Commerce Protocol specifies how an agent discovers your products, builds a cart, and securely hands off payment information for you to process. This allows you to accept orders from millions of AI users while keeping your existing order and payment infrastructure.

How Agentic Commerce Protocol works: the three core specifications

ACP is built around three distinct specifications that govern different parts of the purchase journey.

• The Product Feed Spec: This defines how you tell an AI agent what you have for sale. For an agent to accurately recommend your products, it needs structured, up-to-date information. It is typically a regularly refreshed data file (e.g., JSON, CSV) that you provide via a secure HTTPS endpoint, containing key product details like IDs, descriptions, pricing, inventory, and images.
• The Agentic Checkout Spec: This is the core of ACP, defining the REST APIs that allow you to render a complete checkout experience directly within the ChatGPT user interface. While the checkout is delivered within the agent experience, your system remains in complete control. The agent collects the user's information (like a shipping address) and passes it to your API, which then performs your standard business logic: validating the address, calculating taxes and shipping, and running fraud checks.
• The Delegated Payment Spec: This specification outlines how payment details are handled securely, ensuring that the AI agent never touches or stores raw payment credentials. The agent helps the user select a payment method stored in their account (currently, only cards are supported), setting the maximum authorized amount and validity period based on the selected purchase. It then makes a request to a compliant Payment Service Provider (PSP), which returns a single-use payment token. This token is passed to you, and you use it with your payment APIs to complete the charge, just as you would in a typical e-commerce flow.

The end-to-end Agentic Commerce Protocol flow

Here is a simplified, step-by-step look at how a transaction works using ACP.

1. You provide a product feed so the agent knows what you sell.
2. A consumer in ChatGPT decides to buy one of your products.
3. ChatGPT calls your Agentic Checkout API to create a checkout session.
4. Your system validates the request, calculates shipping and taxes, and returns the available options.
5. The consumer confirms the details and provides payment information through a stored payment method within ChatGPT.
6. ChatGPT securely sends the payment details to a compliant PSP, requesting a payment token according to the Delegated Payment Spec.
7. The PSP provides a secure, single-use payment token to OpenAI.
8. OpenAI sends this payment token to your Agentic Checkout API to complete the order.
9. You use this token with your PSP's payment APIs to charge the consumer.
10. You confirm the order is complete and send a confirmation back to OpenAI.

Why is this important for you?

ACP is important because it provides a practical framework for integrating your existing commerce systems into conversational AI, balancing a seamless user experience with your need for control and security.

• It creates a seamless user experience: An accurate product feed ensures the agent shows correct pricing and availability, while the Agentic Checkout Spec allows the entire checkout to happen within the conversational UI. This prevents consumer frustration and reduces cart abandonment by eliminating the need to visit an external website.
• You remain in control: Although the checkout is rendered in the agent's interface, all critical business logic, validation, and final decision-making (accepting or declining an order) happen on your servers. You don't have to change your existing order management processes.
• It simplifies security and compliance: The Delegated Payment Spec is designed to help keep your integration out of complex PCI scope. The agent facilitates the payment without handling sensitive data, and you process the transaction using a secure token - a process you are already familiar with.

Get Started

To begin integrating with ACP, the official OpenAI Commerce developer documentation is your primary resource. It contains the complete technical specifications, implementation guides, and all the information required to get started.