Shopify opens checkout to browser-based AI agents

Shopify announced on September 28, 2026 that it is adding WebMCP support to checkout, including Shop Pay, allowing browser-based AI agents to complete purchases on merchant sites. The company had previously supported WebMCP for storefronts and carts, enabling agents to browse inventory, search products, and add items to a cart. With checkout support, agents can now read and update the checkout screen and submit the transaction after receiving buyer authorization, without relying on screenshots or scraping webpages.

The update introduces three tools — get_checkout, update_checkout, and complete_checkout — that let agents inspect a checkout, change details such as the customer's address or delivery option, and place an order once the buyer authorizes it. The feature is rolling out to all eligible Shopify merchants, according to Gil Greenberg, Shopify's staff product manager for agentic commerce.

WebMCP is a proposed standard designed for agents that operate inside the buyer's browser. Shopify already offers a hosted Model Context Protocol (MCP) server for server-to-server agent work, and both approaches leverage Shopify's Universal Commerce Protocol (UCP). Shopify also noted that AI agents such as Muse and Instinct already have direct partnerships with Shopify for agentic commerce, with the Instinct partnership announced the same day.