Agentic Commerce Protocol (ACP)
The Agentic Commerce Protocol (ACP) is the open standard from OpenAI and Stripe that lets AI agents such as ChatGPT read a merchant's product feed and run a checkout against the merchant's own systems. Today its biggest SEO impact is the product feed that drives shopping discovery in ChatGPT.
  • ACP is Apache 2.0 licensed, maintained by OpenAI and Stripe, still labelled beta, and versioned by date (latest stable 2026-04-17).
  • It has four parts: a product feed, five checkout session endpoints, signed order webhooks and a delegated payment token.
  • The feed is a file: JSONL in OpenAI's format, or a Google-compatible TSV or CSV, optionally gzipped.
  • ChatGPT Instant Checkout was scaled back in March 2026. ACP now mainly powers product discovery, with most purchases finishing on the merchant's own checkout.
  • Feed access is for approved partners, so apply at chatgpt.com/merchants or go through a platform such as Shopify, Stripe or Salesforce.

The Agentic Commerce Protocol (ACP) defines how an AI agent and a merchant exchange product data, run a checkout and pass a scoped payment credential. OpenAI launched it with Stripe on 29 September 2025 alongside Instant Checkout in ChatGPT. The spec is open source on GitHub, documented at agenticcommerce.dev and OpenAI's developer site, and the merchant stays the merchant of record throughout.

Why it matters

ChatGPT is one of the biggest places people now ask for product recommendations. Which products it can show, with what price and stock, depends heavily on the feed you supply through ACP. If you are not in the feed, you rely on what its crawlers and third-party pages say about you.

The four parts

1. The product feed (the file that matters most)

The feed tells the agent what you sell. OpenAI accepts JSONL in its own format or a Google-compatible delimited file (TSV or CSV, optionally gzipped). Required fields in the OpenAI format include item_id, title, description, url, brand, seller_name, image_url, availability and price. Titles are capped at 150 characters and descriptions at 5,000.

 {"item_id":"SKU-123-RED-9","group_id":"SKU-123","title":"Trail Runner waterproof shoe, red","brand":"Example","price":"120.00 GBP","availability":"in_stock","url":"https://www.example.com/p/trail-runner","image_url":"https://www.example.com/img/trail-runner-red.jpg","is_eligible_search":true}
  • Variants are flattened: one row per buyable item, linked by a shared group_id.
  • Flags control placement: is_eligible_search, is_eligible_checkout and is_ads_eligible.
  • Upload a full file daily and update price and stock far more often. A mismatch between quoted and charged price fails the checkout.
  • The 2026-04-17 version adds a push-style Feed API for upserting products.

2. Checkout endpoints

The merchant hosts five HTTPS endpoints: create, update, retrieve, complete and cancel a checkout session (POST /checkout_sessions and so on). Every response returns the full cart with tax, delivery options and totals.

3. Order webhooks

The merchant sends signed order_created and order_updated events back as orders ship or are refunded.

4. Delegated payment

The agent passes a single-use token, capped at the checkout total and tied to one merchant and session, instead of a card number. Stripe's Shared Payment Token was the first implementation, and PayPal supports it for Braintree merchants.

Where things stand

On 24 March 2026 OpenAI said Instant Checkout had not offered enough flexibility and shifted its focus to discovery, letting merchants use their own checkout. ACP was extended to carry feeds and promotions, and retailers including Target, Sephora, Best Buy and Wayfair are integrated for discovery. Shopify merchants appear in ChatGPT and complete purchases on their own store checkout in an in-app browser.

ACP vs UCP

  • ACP: OpenAI and Stripe, feed plus merchant-hosted checkout, payment via a delegated PSP token.
  • UCP: Google with major retailers, discovery via /.well-known/ucp, runs over REST, MCP or A2A, payment via Google Pay in Google's surfaces.

If you want to be bought in both ChatGPT and Gemini, expect to support both, or use a provider that translates for you.

Common mistakes

  • Feed prices and stock lagging the website.
  • Variants bundled into one row instead of flattened.
  • Product pages blocked to OAI-SearchBot or ChatGPT-User at the CDN.
  • Thin, keyword-stuffed titles copied from an old shopping feed.
  • Selling restricted categories (alcohol, nicotine, weapons and similar), which are not eligible.

The GEO angle

The ACP feed is effectively a shopping sitemap for ChatGPT. Treat it like your Merchant Center feed: accurate, rich attributes, real images and frequent updates. Pair it with server-rendered Product schema so crawlers and the feed tell the same story.

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