UCP Readiness Checker - an open, API-first validator that grades any store A–F

[WeareprestaDev]

Hey all! 👋 We work on tools that help online stores get ready for AI shopping agents over UCP.

While building that, we wanted a quick way to answer "Is this store actually UCP-ready?" - and the checkers we found were mostly out of date, testing against older versions of the spec and having different flaws. Since the spec keeps moving, we built one that stays pinned to the current version.

With the UCP's open-source nature in mind, we've put it online for anyone to use. No signup, no login.

Try it right now - paste a store URL:

curl -X POST https://checker.ucphub.ai/check \
  -H 'content-type: application/json' \
  -d '{"url": "https://your-store.example"}'

You get back a simple grade (A-F), a score, and a list of what passed and what didn't. The /check probes /.well-known/ucp, robots.txt, llms.txt, and agents.md.

There's also a /validate endpoint if you just want to check a UCP document against the official schemas (handy while you're building - you can even run it before you commit).

curl -X POST https://checker.ucphub.ai/validate \
  -H 'content-type: application/json' \
  -d '{
    "document": { "id": "cod", "version": "2026-04-08", "config": { "title": "Cash on delivery" } },
    "type": "payment_handler"
  }'

Docs is available at https://docs.ucphub.ai/docs

The API is free to use under Apache-2.0 (attribution appreciated), and we're preparing the validator packages for public release.

We'd love this community's feedback - especially on spec fidelity.
Does the grading and schema validation match how you read the current spec? Anywhere we're too strict or too lenient? We're keeping it aligned to the latest UCP version and want to keep it that way, so gut-checks here are genuinely valuable.

[Ag1729]

Interesting will give it a try

…

On Fri, 31 Jul 2026 at 8:07 PM, Wearepresta ***@***.***> wrote: Hey all! 👋 We work on tools that help online stores get ready for AI shopping agents over UCP. While building that, we wanted a quick way to answer "Is this store actually UCP-ready?" - and the checkers we found were mostly out of date, testing against older versions of the spec and having different flaws. Since the spec keeps moving, we built one that stays pinned to the current version. With the UCP's open-source nature in mind, we've put it online for anyone to use. No signup, no login. *Try it right now* - paste a store URL: curl -X POST https://checker.ucphub.ai/check \ -H 'content-type: application/json' \ -d '{"url": "https://your-store.example"}' You get back a simple grade (A-F), a score, and a list of what passed and what didn't. The /check probes /.well-known/ucp, robots.txt, llms.txt, and agents.md. There's also a /validate endpoint if you just want to check a UCP document against the official schemas (handy while you're building - you can even run it before you commit). curl -X POST https://checker.ucphub.ai/validate \ -H 'content-type: application/json' \ -d '{ "document": { "id": "cod", "version": "2026-04-08", "config": { "title": "Cash on delivery" } }, "type": "payment_handler" }' Docs is available at https://docs.ucphub.ai/docs The API is free to use under Apache-2.0 (attribution appreciated), and we're preparing the validator packages for public release. We'd love this community's feedback - especially on spec fidelity. Does the grading and schema validation match how you read the current spec? Anywhere we're too strict or too lenient? We're keeping it aligned to the latest UCP version and want to keep it that way, so gut-checks here are genuinely valuable. — Reply to this email directly, view it on GitHub <#656?email_source=notifications&email_token=BK6DTBS2JTC6IECLG3LCQZL5HSVLZA5CNFSNUABBM5UWIORPF5TWS5BNNB2WEL2ENFZWG5LTONUW63RPGEYDKMZRGMYDTJTSMVQXG33OVJZXKYTTMNZGSYTFMSSWK5TFNZ2KYZTPN52GK4S7MNWGSY3L>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/BK6DTBTG33GQH2BAPEHXBT35HSVLZAVCNFSNUABJKJSXA33TNF2G64TZHMYTCMRVGU4TCOBUGE5UI2LTMN2XG43JN5XDWMJQGUZTCMZQHGQXMAQ> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[WeareprestaDev]

Thanks! Any feedback would be appreciated.

[zologic]

Why is your solution better than the https://ucpchecker.com?

[WeareprestaDev]

UCP Checker is excellent, especially the merchant directory and catalog-level checks. We're not trying to position ours as "better"; it comes from a different place.

This is the validation engine we built internally to onboard stores onto UCP through our own product, and we open-sourced it (Apache-2.0) rather than keeping it as a hosted-only service. A few things that fall out of that:

• It validates any UCP artifact (checkout sessions, carts, orders, payment handlers — not just the discovery profile) fully offline and stateless, so you can drop it into CI.
• It tracks the upstream draft spec, so you can validate against the next version before it ships.
• Because our own e2e suite and CI drift-guard run on the same code, it stays current with the spec by necessity, not by promise.

The ecosystem benefits from both — a hosted observatory like yours and an embeddable open validator complement each other.

Happy to chat if there's room to collaborate.