The agentic commerce stack, reviewed

OpenAI launched Instant Checkout on 29 September 2025, and Stripe released the Agentic Commerce Protocol alongside it. In March 2026 Stripe expanded Shared Payment Tokens, which let AI agents initiate payments without exposing card credentials, to support Visa Intelligent Commerce, Mastercard Agent Pay, Affirm and Klarna through a single integration.

Shopify's Winter '26 Edition introduced Agentic Storefronts and Shopify Catalog, structured product data formatted for AI models, letting merchants toggle on ChatGPT, Perplexity and Microsoft Copilot as channels from the admin. Activation for all stores began in late March 2026, and products syndicate through the Catalog unless a merchant opts out.

The opt-out default is the part most merchants miss. From late March 2026 a Shopify catalogue syndicates to agent channels unless someone actively prevents it, which means the decision has already been made for most stores whether or not anyone reviewed it. That is worth an explicit check rather than an assumption, because it changes which surfaces carry your pricing and product data.

It also changes what the product data has to be. An agent reads structured catalogue fields rather than a landing page, so incomplete attributes, missing variants and thin descriptions degrade the listing in a channel nobody on the team is looking at. The same discipline that makes a page citable in an AI Overview, where click-through runs at 8 per cent, makes a product legible to a purchasing agent.

The honest position in September 2026 is that the rails are real and the volume is early. The case for acting is not forecast demand, it is that the cost of being correctly listed is close to zero once the catalogue is clean, while the cost of being absent is invisible and therefore never gets measured. With 68.01 per cent of United States searches already ending without a click, an acquisition plan that assumes every buyer arrives through a browser session is planning for a shrinking share of them.