Understanding the Universal Commerce Protocol (UCP) Profile
What is a UCP Profile?
While an llms.txt file is designed to give AI agents a broad overview of your site's structure, the Universal Commerce Protocol (UCP) Profile is specifically designed for transactions. It is a strictly structured JSON file that maps exactly which commerce actions your site supports and where the API endpoints for those actions are located.
By hosting a ucp.json file, you are explicitly telling an AI assistant (like a shopping bot in ChatGPT) exactly how to search your catalog, how to add an item to a cart on behalf of a user, and how to hand off the user to a secure checkout flow.
How AI Agents Use Your Profile
When an AI agent is tasked with finding and purchasing a product, it will look for the /.well-known/ucp endpoint on your domain. If it finds a valid profile, it reads the services array. If it sees that you support product.search and cart.add, it can interact with your store programmatically without ever parsing your HTML or executing your frontend JavaScript.
This creates a frictionless shopping experience. The user stays inside their AI chat interface to browse and select products, and is only redirected to your site for the final, secure checkout step.
Where to Host the File
The UCP specification requires that this JSON profile be hosted at the Well-Known URI location on your primary domain. You do not need the `.json` extension in the URL route, but the server must return it with an application/json content type.
Required Location: https://yourstore.com/.well-known/ucp