Some retailers—Amazon and Adidas among them—have decided to prevent AI agents from completing purchases on behalf of users on their platforms. Shopify, however, has taken the opposite approach. On Monday, the e-commerce company revealed that browser-based AI agents are now able to finalize purchases on Shopify merchants' sites, expanding what they can do beyond simply searching for products and adding them to shopping carts.

Previously, Shopify had supported WebMCP for its storefronts and carts, which let browser-based AI agents browse a Shopify retailer's inventory, search for products, and place them into a cart. With the new WebMCP support for checkout—including Shop Pay—these agents can now read the checkout screen, make updates to it, and submit the transaction once the buyer authorizes it, all without needing to rely on screenshots or scraping webpages, according to the company.

This update brings three new tools—get_checkout, update_checkout, and complete_checkout—which enable agents to examine a checkout, modify details such as the customer's address or delivery option, and then place an order after the buyer gives authorization. The feature is being rolled out to all eligible Shopify merchants, according to Gil Greenberg, a staff product manager focused on agentic commerce at Shopify, who shared the news in a post on X.

Shopify already provides a hosted Model Context Protocol (MCP) server, which lets agents operate server-to-server. The proposed WebMCP standard, on the other hand, is built for agents that function within the buyer's browser. Both make use of Shopify's Universal Commerce Protocol (UCP), which offers a shared method for searching and discovering products, building carts, and checking out. Leading AI agents such as Muse and Instinct already have direct partnerships with Shopify for agentic commerce, with the Instinct partnership being announced today.

"If your agent is operating in the buyer's browser, use WebMCP tools provided on storefront and checkout to efficiently complete order placement, instead of navigating HTML built for humans," Greenberg wrote on X. "These WebMCP tools provide structured and efficient APIs, purposely designed - via UCP - to ensure accurate commerce facts, required disclosures, and handoff requirements."