Shopify has begun allowing browser-based AI agents to complete purchases on users’ behalf in stores on the platform. The company made the announcement on Monday, September 28, 2026. Agents could previously search for products and add them to the cart; with WebMCP and Shop Pay support, they can now read and update the checkout and submit the transaction with the buyer’s approval.
The update offers three new tools for managing the checkout process:
- get_checkout: Allows checkout information to be reviewed.
- update_checkout: Enables information such as the customer’s address or delivery option to be changed.
- complete_checkout: Completes the order after the buyer’s approval.
The feature is being rolled out to all eligible Shopify stores. Unlike Shopify’s server-to-server hosted Model Context Protocol (MCP) server, the proposed WebMCP is designed for agents that run inside the buyer’s browser. Both systems use the Universal Commerce Protocol (UCP), which provides a common structure for product search, cart creation, and checkout.
Muse and Instinct AI agents have direct agentic commerce partnerships with Shopify; the Instinct partnership was announced on the same day. Shopify said that WebMCP tools offer a more structured and efficient checkout process instead of navigating HTML pages designed for humans.
Why it matters
This step moves AI agents beyond product discovery and cart preparation to agents that can complete a commercial transaction with the user’s approval. The main impact of the change is that the shopping experience can be conducted through structured tools inside the browser instead of by navigating human-designed pages one by one; this concerns both stores and the teams developing these agents. The distinction between WebMCP and the server-side MCP approach brings the question of where the agent runs and how it connects to the payment flow to the forefront. Although using UCP as a common structure facilitates the connection, how consistently address, delivery, and approval steps will work across different stores remains an open question.
Term: agent
An AI agent is software that calls tools and carries out multistep tasks to achieve a goal instead of producing a single response.