SourceCited / Agentic commerce
Guide · Agentic commerce
Assistants are starting to buy, not just recommend. The ACP, AP2 and UCP protocols are young and shifting — but the prep work is concrete and serves you either way.
Two protocol families lead AI checkout: ACP (OpenAI/Stripe — product feed to chatgpt.com/merchants, Shared Payment Token, ~4% fee) and Google's AP2 + UCP (Merchant Center feed, signed mandates, native_commerce flag). Prep the shared layer now — complete Product/Offer schema, fresh dual feeds, extractable product pages — and treat every protocol detail as dated: this space restructured within months of launching.
AI assistants are beginning to complete checkouts inside the conversation. Two protocol families lead: OpenAI/Stripe's ACP behind ChatGPT checkout, and Google's AP2 + Universal Commerce Protocol (UCP) behind AI Mode, Gemini, and Shopping. In both stacks you remain the merchant of record — the assistant is the storefront, not the seller.
ACP (Agentic Commerce Protocol) is open (Apache-2.0), built by OpenAI with Stripe. You push a product feed (CSV/TSV/XML/JSON, refresh as often as every 15 minutes) to chatgpt.com/merchants; payment runs on a Shared Payment Token so the agent never touches the card; OpenAI charges roughly a 4% merchant fee plus normal payment processing.
Single-item Instant Checkout opened to all US users in February 2026, then was reportedly restructured within weeks amid thin merchant uptake. Build the feed anyway — it powers discovery either way — but date-stamp every assumption and re-verify terms before launch.
AP2 (announced Sept 16, 2025, with 60+ payment partners) is the authorization layer: signed Intent, Cart, and Payment mandates issued as verifiable credentials, with a stablecoin extension (x402). UCP (early 2026) is the commerce layer: it runs on your existing Google Merchant Center feed and, with the native_commerce flag, enables an in-surface Buy button across Search AI Mode, Gemini, and Shopping. The protocols are designed to interoperate.
| Prepare | Why |
|---|---|
| Complete Product/Offer schema — GTIN/MPN, price, availability, variants, returns | It is the data layer every AI shopping surface reads |
| Fresh feeds to Google Merchant Center and chatgpt.com/merchants | The protocols will coexist — prepare for both |
| Product pages with specs as text, not images | Agents cannot read a spec sheet trapped in a JPEG |
| Agent-friendly checkout (see the agent-ready guide) | Every extra step is a failure point for an automated buyer |
From this product page (HTML) and my current feed row: 1) generate spec-complete Product+Offer JSON-LD (GTIN/MPN, price, priceCurrency, availability, condition, shipping, returns); 2) flag every field missing or inconsistent across page, schema, and feed — those gaps block AI shopping surfaces; 3) output a corrected feed row.
Plan for both — they will likely coexist. The shared layer (complete Product/Offer schema, accurate high-frequency feeds, clean product pages) serves both; enable each surface as it stabilizes.
Under ACP, roughly a 4% merchant fee plus normal payment processing, per current terms. Terms are moving — re-verify before launch rather than trusting any article, including this one.
Partially and unevenly. It launched, expanded to all US ChatGPT users in February 2026, and was then reportedly restructured amid thin merchant uptake. Treat 2026 as the preparation window, not the harvest.