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.

  • Freeno account needed
  • Server sidefetched from our servers, not your browser
  • Spec alignedchecks the fields defined at ucp.dev

We will check https://your-domain/.well-known/ucp.

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 as a string.

Required

ucp.services lists at least one service with a version and a transport binding, such as rest, mcp, or a2a.

Required

ucp.capabilities is an array where each entry declares a name, version, spec, and schema.

Required

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

Recommended

payment.handlers lists at least one handler with an id, name, and config_schema.

Recommended

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

Frequently asked questions

What is the Universal Commerce Protocol?
UCP is an open source standard developed by Google with partners including Shopify, Etsy, Wayfair, Target, and Walmart. It gives AI agents a common way to discover a business's products, run checkout, and apply discounts, replacing one off integrations built per platform.
Where does a UCP manifest live on a website?
At the well known path /.well-known/ucp. It is a JSON document listing the services and capabilities a business supports, along with accepted payment handlers.
What does this checker actually validate?
It confirms the manifest exists, is valid JSON, and contains the required ucp.version, ucp.services, and ucp.capabilities fields in the shape the protocol expects. It also flags common but non required fields, such as payment handlers.
Is this an official Google or ucp.dev tool?
No. This is an independent checker built against the publicly documented manifest structure. For the authoritative specification, see ucp.dev and the UCP GitHub repository.