ACP: Agentic Commerce Protocol

What is ACP?

The Agentic Commerce Protocol (ACP) is the checkout standard behind shopping inside ChatGPT. OpenAI and Stripe maintain it together as “founding maintainers”. It defines how an agent and a merchant exchange a cart, an order and a payment credential, so a user can buy without leaving the conversation.

This page used to cover “OpenAI commerce” in general: Actions, function calling and Operator. It now covers ACP, the open checkout standard OpenAI maintains with Stripe.

How It Works

1. Product feed: the merchant publishes a structured catalog that agents can read.
2. Checkout session: the agent creates and updates a cart with the merchant through the ACP API.
3. Payment credential: the agent passes a payment credential, such as Stripe’s Shared Payment Token.
4. Order: the merchant creates the order and charges through its payment provider.

What Changed in 2026

• April 2026: a new stable spec added cart, product feed, orders, auth and MCP support.
• March 2026: OpenAI scaled back ChatGPT Instant Checkout and moved toward merchant-owned checkout and product discovery, according to industry reporting. ACP as a spec continues.

So if you sell through AI assistants, ACP matters less as a “buy button in ChatGPT” and more as a standard way to expose your catalog and checkout to agents. To see where your store stands today, run through our agent-ready checkout audit checklist for GCC merchants.

ACP vs the Other Protocols

ACP sits in the authorization and checkout layer next to AP2. Money still moves on card rails, or on newer rails such as MPP and x402. See the full protocol comparison.

Our ACP Services

• Catalog and checkout readiness: product feeds and checkout endpoints that agents can use
• Payment credential handling: payment tokens, limits and refunds
• Security audit: token scope, replay and order-integrity review

Last updated October 9, 2026