For shoppers, platforms & developers

Shop Three Rivers with an AI agent

This store speaks the Universal Commerce Protocol (UCP) through CartThrob AI. Agents prepare the order. You always review and pay on this website.

Discover
A shopping platform reads the store's business profile at /.well-known/ucp. The profile lists capabilities, the REST endpoint and the public keys for verifying signed responses and webhooks.
Search the catalog
The agent calls POST /ucp/v1/catalog/search and /catalog/product. Products, variants (size & grind), stock and prices come straight from CartThrob.
Build a cart & checkout
Signed requests create a cart, apply coupons such as WELCOME10, add a shipping address and pick a shipping method. CartThrob calculates discounts, shipping and Pennsylvania sales tax.
Hand off to you
Completing the checkout returns requires_escalation and a single-use continue_url. Following it loads the prepared cart into your browser and brings you to checkout.
Pay here
You review the order and pay through the store's normal CartThrob checkout. The agent never sees card details.
Order sync
The native order is linked back to the agent's checkout, which now reads completed. A signed order webhook is sent to the platform.

Endpoints

Discovery: https://nerdee.dev/.well-known/ucp
REST base: https://nerdee.dev/ucp/v1
Protocol version: 2026-08-25
Authentication: RFC 9421 signatures verified against the platform profile, or a registered platform key