ACP for Online Merchants

The Agentic Commerce Protocol opens a new sales channel for merchants: AI agents like ChatGPT become the storefront. This guide covers what online merchants need to know — from requirements through integration to the ACP readiness checklist.

Why Merchants Should Pay Attention to ACP

ChatGPT has over 700 million weekly users. More and more of these users are researching products via AI assistants instead of Google. With Instant Checkout in ChatGPT, they can also buy directly there — provided the merchant supports the protocol.

For merchants, ACP means:

• New sales channel: Products become visible where millions of users already are — in the chat
• No marketplace account needed: Unlike Amazon or eBay, a technical integration is sufficient
• Lower customer acquisition costs: The agent recommends based on relevance, not advertising spend
• First-mover advantage: Those who integrate now will already be visible when impressions from traditional channels decline

The flip side: those who don't integrate become invisible to AI agents. When a ChatGPT user asks "Find me running shoes under 120 euros," only ACP-compatible stores appear in the results.

Requirements for Integration

Not every store can use ACP immediately. The key requirements:

• Structured product data: Your products must be available in a machine-readable format — with prices, availability, variants, and descriptions
• API-capable backend: Your store must be able to accept orders via an API (not just via a web form)
• Payment integration: A payment provider that can process SharedPaymentTokens (Stripe, with more to come)
• HTTPS: Encrypted connection is mandatory

If your store runs on Shopify, BigCommerce, or another modern e-commerce system, these requirements are typically already met.

Preparing the Product Feed

The Product Feed is the data foundation for AI agents. It must contain the following information per product:

Field	Description	Required
product_id	Unique product ID	Yes
title	Product name	Yes
description	Description (machine-readable, precise)	Yes
price	Current price with currency	Yes
availability	Availability (in_stock, out_of_stock, preorder)	Yes
variants	Sizes, colors, other options	If applicable
images	Product images (URLs)	Recommended
categories	Product categories and tags	Recommended
checkout_enabled	Whether ACP checkout is possible	Yes

If you already maintain Google Shopping Feeds or Facebook Product Catalogs, the structure is familiar. The ACP Product Feed requires similar data, but in a specific JSON format.

Tip: Invest in the quality of your product descriptions. AI agents make recommendations based on this data — inaccurate or incomplete descriptions mean your products won't be recommended.

Implementing the Checkout API

Your backend must provide the four Checkout API endpoints. At its core, this means:

• CreateCheckout: Agent sends product IDs and quantities → your system creates a cart and calculates prices
• UpdateCheckout: Agent modifies the cart → your system recalculates
• CompleteCheckout: Agent sends payment token → your system processes the payment and creates the order
• CancelCheckout: Agent cancels → your system releases reserved inventory

Crucially: the logic for price calculation, tax, shipping costs, and availability checks remains in your system. The agent is merely a channel — like an additional marketplace that submits orders via your API.

Platform Integrations

Stripe Agentic Commerce Suite

For merchants already using Stripe as their payment provider, the Agentic Commerce Suite offers the fastest entry point. The suite handles the creation and management of SharedPaymentTokens and provides pre-built checkout endpoints. For many Stripe customers, integration is reduced to providing the Product Feed.

Shopify

Shopify merchants benefit from native support. Shopify provides an MCP server that makes the product catalog, checkout, and order management accessible to AI agents. Over one million merchants are in the pipeline for automatic activation.

BigCommerce

BigCommerce has announced a native ACP integration. Merchants on this platform will likely become ACP-compatible via a plugin or app store integration.

Headless Commerce as an Advantage

Stores with headless architecture — meaning a separation of frontend and backend — have a natural advantage with ACP integration. Why? Because the API infrastructure already exists.

A headless store typically already has REST or GraphQL endpoints for product queries, cart management, and checkout. ACP integration in many cases simply means wrapping these existing endpoints in the ACP format — no fundamental rebuild required.

For stores with traditional, monolithic architecture (e.g., WooCommerce, Magento without headless setup), the effort is higher, as the checkout logic is typically embedded in the HTML rendering pipeline and must first be extracted for API access.

ACP Readiness Checklist

Ten steps to ACP readiness:

1. Audit product data: Are all products stored with complete, machine-readable data (title, description, price, variants, availability)?
2. Create Product Feed: Provide product data in ACP-compliant JSON format
3. Check API capability: Can your backend accept orders via a REST API?
4. Implement checkout endpoints: Provide the four ACP endpoints (Create, Update, Complete, Cancel)
5. Set up payment integration: SharedPaymentToken processing via Stripe or a compatible provider
6. Set up authentication: Bearer tokens and HMAC signatures for API security
7. Activate test mode: Sandbox environment for integration without real transactions
8. Ensure error handling: Structured error messages for all edge cases (out of stock, address not serviceable, minimum order value)
9. Set up monitoring: Track ACP transactions, conversion rates, and error rates
10. Train the team: Customer service must be able to identify and process ACP orders

Cost and Effort

A realistic assessment:

Scenario	Effort	Cost
Shopify merchant	Minimal (configuration)	Included in Shopify plan
Stripe customer with API	1-5 days development	Stripe transaction fees
Custom backend (headless)	1-3 weeks	Development costs + payment fees
Monolithic store	3-6 weeks	Higher development costs, possibly architecture changes

The protocol itself is free and open source. Ongoing costs arise from payment transaction fees (as with any sales channel) and potentially hosting for the API endpoints.