UCP Checker & Validator /.well-known/ucp

Find out if a site speaks UCP.

Enter a domain and this tool requests its Universal Commerce Protocol manifest at /.well-known/ucp, then checks the response against the structure agents expect: services, capabilities, and payment handlers.

Enter a domain, like flowershop.example, or a full URL, like https://flowershop.example.

  • Free forever
  • Instant report
  • No account needed

How the check works

Three steps, run fresh every time you submit a domain. Nothing is cached from a prior check.

Step 1

Request the manifest

Our server sends a GET request to https://your-domain/.well-known/ucp and follows redirects, the same way an agent would.

Step 2

Parse and compare

The response is parsed as JSON and compared field by field against the manifest structure UCP defines for services, capabilities, and payment handlers.

Step 3

Report plainly

You get a line by line report: what was found, what is missing, and what is recommended but optional, with no jargon left unexplained.

What we check

Required checks must pass for a manifest to be marked valid. Recommended checks are reported as warnings and do not block a pass.

Required

ucp.version is present and matches a known spec version (currently 2026-04-08).

Required

ucp.services is an object keyed by service name, where each entry is an array of descriptors with a version and a transport of rest, mcp, a2a, or embedded. Endpoints and schemas are recommended.

Required

ucp.payment_handlers is an object keyed by handler namespace, where each descriptor declares an id and version.

Required

A root level signing_keys array is present. An empty array is valid if you are not signing payloads yet.

Required

The manifest is served as valid, parseable JSON at the well known path.

Recommended

ucp.capabilities is declared as an object keyed by capability name, where each entry is an array of versioned declarations. Optional, but agents use it to match your store to shopping intents.

Recommended

The manifest is served over HTTPS with a Content-Type of application/json.

Why this matters

UCP launched in January 2026. Here is what the people building it, and the analysts tracking it, have actually said.

$3–5 trillion

McKinsey research estimates AI agents could mediate $3 trillion to $5 trillion of global consumer commerce by 2030.

McKinsey & Company

“…the industry needs a protocol that works at global scale…”

Sundar Pichai, CEO of Google and Alphabet, on the rationale for UCP at the NRF 2026 keynote where it was announced.

NRF, coverage of the keynote

“…agentic commerce is no longer just a concept, it’s reality…”

Vidhya Srinivasan, VP and GM of Ads and Commerce at Google, writing on where agentic shopping stood as of February 2026.

PYMNTS

20+ launch partners

UCP was co-developed with Shopify, Etsy, Wayfair, Target, and Walmart, and is endorsed by more than 20 companies including Visa, Mastercard, Stripe, and The Home Depot.

Google Developers Blog

Frequently asked questions