How do I tell whether my store already supports agent checkout?

The two requests

Neither needs a key, a sandbox or a partner agreement, and both are safe to run against your own production storefront — they read a discovery document and list capabilities. Nothing is created and no order is placed.

Run them against the domain customers actually type. That detail matters more than it sounds: a headless front-end at your customer domain may not proxy the paths your commerce backend serves, so checking the backend host can tell you the opposite of what an agent arriving at your brand domain would find.

• GET https://yourdomain.com/.well-known/ucp — a JSON profile means discovery is live.
• POST a JSON-RPC tools/list request to the MCP endpoint that profile names — the response lists the commerce tools an agent may call.
• Read the content-type on both. A 200 that returns text/html is your catch-all page, not a document.

Reading the result honestly

A successful discovery response is not proof that an agent can buy from you. In every store we tested, listing the tools was open while calling them required the calling agent to present its own resolvable identity — so an anonymous script gets a refusal even where a genuine agent would not.

A 404 is equally not proof of absence. It tells you nothing is served at that path on that host today. Several stores we checked run the same commerce platform as the 70 that answered, and returned 404 anyway, which points at the front-end rather than at the platform.

What the check does settle is the question worth settling: whether the surface exists without anybody at your company deciding it should.

What to do if the answer is yes

Treat it as a live channel that arrived without a launch. The operational assumptions behind it are the same ones behind any other sales channel, and none of them have been reviewed for this one.

The questions worth asking in the first week are unglamorous and all answerable internally.

• Is inventory accurate enough to be quoted by a machine that will not re-check before committing?
• Which payment methods are registered, and did anyone choose them with agents in mind?
• Who handles a refund or a support request for an order nobody browsed for?
• Does your analytics distinguish these orders at all, or are they landing in an existing bucket unlabelled?

What the file at /llms.txt does not tell you

It is tempting to audit this from llms.txt, because it is the file everyone talks about. It is a poor proxy. Twelve of the 70 stores that answered a discovery request published an llms.txt that never mentions the endpoints, and seven of those served no llms.txt at all.

So a store can be fully agent-transactable and score zero on an llms.txt audit. Check the discovery path directly.