UCP capability families declared

What we check

We sort the capabilities under ucp.capabilities into families: checkout (dev.ucp.shopping.checkout), cart, order, catalog (catalog.search and catalog.lookup), identity linking and location. An extension or a vendor capability counts toward the family of the capability it extends. The families are UCP Checker's grouping; we did not find the term in the UCP spec. We use the same grouping so the two results can be compared.

Why it matters

Capabilities tell an agent what it may do at your store. The checkout capability is the one that covers placing an order; catalog, cart and order cover finding products, the basket and the order after it is placed. The spec makes capabilities optional, but a useful commerce profile normally declares at least one.

How we check

Checkout is worth half the score. Catalog, cart and order share the other half equally. We report identity linking and location but do not require them, since a shop that sells only online has no reason to offer location search. A score of 80 or more is a PASS and 40 or more is a WARN. Checkout alone scores 50, a WARN, and so do catalog, cart and order without checkout. FAIL: no capability is in any family, including when there are no capabilities at all or the profile has no ucp.version. SKIPPED: there is no profile, we could not read it, or it is not JSON.

How to fix it

1. Declare dev.ucp.shopping.checkout under ucp.capabilities so agents can buy.
2. Declare the catalog, cart and order capabilities your platform supports, each with its version and spec URL.

What good looks like

"capabilities": {
  "dev.ucp.shopping.checkout": [{ "version": "2026-08-25", ... }],
  "dev.ucp.shopping.cart": [{ "version": "2026-08-25", ... }],
  "dev.ucp.shopping.order": [{ "version": "2026-08-25", ... }],
  "dev.ucp.shopping.catalog.search": [{ "version": "2026-08-25", ... }],
  "dev.ucp.shopping.catalog.lookup": [{ "version": "2026-08-25", ... }]
}

Sources

• UCP 2026-08-25 specification: overview
• UCP 2026-08-25 checkout capability
• UCP Checker: how we check

Read more

• UCP explained

  The Universal Commerce Protocol: the profile a store publishes at /.well-known/ucp, the capabilities it declares there, and the checkout flow from a new basket to a placed order.