Agentic Commerce Protocol (ACP)

The Agentic Commerce Protocol is an open-source standard developed by Stripe and OpenAI that enables AI agents to complete purchases on behalf of consumers through a structured checkout flow.

ACP defines the interaction model between three participants: the buyer, their AI agent (such as ChatGPT), and the merchant's commerce system. Released under the Apache 2.0 license in September 2025, ACP powers ChatGPT's Instant Checkout feature -- the "Buy" button that lets consumers purchase products directly inside a conversation without visiting the merchant's website.

Before ACP, every AI shopping integration required custom development. A merchant wanting to sell through ChatGPT needed one integration, selling through Copilot needed another, and each new AI platform meant more engineering work. ACP standardizes this: merchants implement the protocol once, and any ACP-compatible AI agent can initiate a purchase.

The protocol specification is maintained on GitHub by OpenAI and Stripe, with community contributions welcome. As of February 2026, ACP is in beta but already processing live transactions for Etsy and expanding to over 1 million Shopify merchants, Walmart, and dozens of other retailers (OpenAI, 2026).

ACP is the protocol behind the fastest-growing AI shopping channel in the world. ChatGPT processes 50 million shopping queries daily and has 800 million weekly active users (OpenAI, 2026). When a consumer clicks "Buy" on a product recommendation inside ChatGPT, ACP is what makes that transaction happen.

The financial impact is already measurable. During Cyber Week 2025, retailers with AI agent integration (largely via ACP) saw roughly 7x better sales growth than those without (Salesforce data, Dec 2025). Adobe Analytics reported that AI-referred visitors show a 38% higher purchase completion rate than traditional search visitors.

For merchants, ACP integration means access to this revenue stream. OpenAI charges a 4% fee on completed Instant Checkout transactions -- a cost structure comparable to marketplace fees. The critical decision is not whether to support ACP, but how quickly you can make your product catalog ACP-compliant.

Stripe's Agentic Commerce Suite, launched December 2025, simplifies adoption. Retailers using Stripe for payments can enable ACP support with minimal development work. The suite includes product discovery optimization, checkout flow simplification, and agentic payment processing. Launch partners include URBN (Anthropologie, Free People, Urban Outfitters), Coach, Kate Spade, Revolve, and Ashley Furniture (Stripe, Dec 2025).

ACP structures the checkout flow into a defined sequence of interactions:

1. Product Discovery. The AI agent presents product options to the consumer based on their stated intent. Products are sourced from merchant catalogs formatted according to OpenAI's commerce feed specification.

2. Product Selection. The consumer selects a product. The agent requests detailed product information from the merchant -- price, variants, availability, shipping options.

3. Checkout Initiation. The agent initiates checkout on behalf of the consumer, sharing payment credentials securely through Stripe's infrastructure. The consumer's actual card details are never exposed to the merchant or the AI agent directly.

4. Order Confirmation. The merchant confirms the order, and the agent relays confirmation details (order number, expected delivery, tracking information) back to the consumer within the conversation.

ACP is designed to be payment-processor flexible -- while Stripe is the primary implementation partner, the protocol specification allows other payment providers. The protocol handles authentication, authorization, and fraud detection through established payment rails.

ACP focuses narrowly on the transaction -- how the agent completes a purchase. UCP covers the entire commerce journey, from discovery to returns. MCP is the data layer that lets agents access product information in real time. Most retailers will need all three over time.

• ACP is the open standard powering ChatGPT's Instant Checkout -- the highest-traffic AI shopping channel
• Over 1 million merchants are already live on ACP through Shopify's auto-enrollment
• OpenAI charges 4% on completed transactions, comparable to marketplace fees
• ACP is complementary to UCP and MCP, not a replacement -- each protocol serves a different function
• Retailers using Stripe can enable ACP support with minimal engineering through the Agentic Commerce Suite