UCP status report

yugicardcenter.store

Q: What is a UCP profile?

The JSON file a store publishes at /.well-known/ucp to tell UCP agents which services it offers, how to call them and how it takes payment. The spec calls it the business profile. yugicardcenter.store's is 3.3 KB, written for UCP 2026-08-25. What goes in a UCP profile.

Q: How was yugicardcenter.store checked?

With public requests on 28 Oct 2026: we read /.well-known/ucp and robots.txt, validated the profile against UCP 2026-08-25, checked that its spec and schema links resolve, and called its REST and MCP service. No sign-in and no purchase. How we check.

Verified

yugicardcenter.store publishes a valid UCP profile. The checks below list what is still worth adding.

BoutirREST, MCPHTTP 200 in 275 msrelease 2026-08-25

UCP Score 96/100 grade A · ready for UCP agents To fix 1 nothing breaks the spec

Passed 18 checks

Checked 28 Oct 03:04 UTC · signed public requests

Findings

18 passed · 1 to fix

Discovery

HTTPS

https

Profile URL uses https://

https

UCP profile reachable

/.well-known/ucp

HTTP 200

/.well-known/ucp

AI bot access

robots.txt

robots.txt allows /.well-known/ucp

robots.txt

UCP profile

To fix

Cryptographic message signing is not yet enabled

keys

Your UCP profile lists no public keys, so cryptographic message signing is not yet enabled for this store. HTTPS already confirms your store's identity; signing adds a further layer for checkout, payment and webhook messages. How to fix →

keys

Profile passes schema validation

ucp

No structural errors

ucp

Protocol version present and well-formed

ucp.version

Version: 2026-08-25

ucp.version

No validation warnings

ucp

No outstanding validation issues

ucp

Spec & schema URLs resolve (11)

spec, schema

All 11 URLs resolved.

spec, schema

Services

Capabilities declared

capabilities

3 of 6 capability families detected: Checkout, Cart Management, Catalog. A family counts once however many namespaces or extensions declare it.

capabilities

Checkout capability

shopping.checkout

dev.ucp.shopping.checkout detected

shopping.checkout

Transports declared

services

REST, MCP

services

Payment handlers

payment_handlers

1 handler registered

payment_handlers

REST transport reachable

transport: rest

Reachable in 196ms (HTTP 200)

transport: rest

MCP transport reachable

transport: mcp

tools/list returned a JSON-RPC response in 890ms

transport: mcp

Outside UCP

llms.txt

/llms.txt

Found at /llms.txt

/llms.txt

sitemap.xml

/sitemap.xml

Found at /sitemap.xml

/sitemap.xml

Open Graph tags

og: meta

og:title and og:type/url present

og: meta

Organization schema (JSON-LD)

JSON-LD

Organization-typed JSON-LD detected

JSON-LD

Mobile viewport meta

meta viewport

meta viewport

Check trace

How yugicardcenter.store answered our check

The five ways an agent can reach this store, what each one met, and every request we made.

2 of 5 open
6 requests · 5.62 s at the store · signed requests

01Hosting ↗

Finding the profile

Open
02Identity Linking ↗

Acting for the buyer

Not offered
03Embedded ↗

In the buyer's browser

Not offered
04Services ↗

Calling its services

Open
05continue_url ↗

Sending the buyer to the website

Not declared

UCP CheckerUCPCheckerBot/1.0

Signed · Web Bot Auth
key K_DlV2MybP…

How to verify us ↗

Finding the profile/.well-known/ucp · 200
1. GET /robots.txt200 OK82 ms
2. GET /.well-known/ucp200 OK270 ms
3. GET www.yugicardcenter.store/.well-known/ucp200 OK1,850 ms
read from profileActing for the buyernot declared
read from profileIn the buyer's browsernot declared
2 requestsCalling its servicesREST, MCP · answered · 10 tools
read from profileSending to the websitenot declared
Outside UCPhomepage · /llms.txt
1. GET /200 OK421 ms
2. GET /llms.txt200 OK872 ms
3. GET /sitemap.xml200 OK3,375 ms

Open

01 · Finding the profile3 requests

Served at /.well-known/ucp with 200 OK, 3.3 KB. robots.txt allows /.well-known/ucp.

Not offered

02 · Acting for the buyerread from profile

The profile doesn't declare identity linking, so an agent can't act for a signed-in buyer.

Not offered

03 · In the buyer's browserread from profile

No Embedded service is declared.

Open

04 · Calling its services2 requests

The REST service answered transport reachable with a UCP response. The MCP service answered tools/list in 890 ms, 10 tools.

Not declared

05 · Sending the buyer to the websiteread from profile

No permalink declared. Whether error replies carry a continue_url shows only in an agent run.

01 · Finding the profile3 requests · 3 × 200 OK2,219 ms

GET /robots.txt 200 OK 520 B · text/plain 82 ms

Answered.

DNS 0 ms
Connect 1 ms
TLS 61 ms
Wait 19 ms
Download 0 ms

URL: https://yugicardcenter.store/robots.txt
Server: 172.67.222.176
Sent user-agent: UCPCheckerBot/1.0 (+https://ucpchecker.com/methodology)
Sent accept: text/plain
Sent signature-agent: "https://ucpchecker.com"
Sent signature: Web Bot Auth (RFC 9421)
Got server: cloudflare
Got content-type: text/plain
Got cache-control: public, max-age=86400
Got cf-ray: a516b684ec62efa9-EWR

GET /.well-known/ucp 200 OK 3.3 KB · application/json 270 ms

Answered.

DNS 0 ms
Connect 1 ms
TLS 70 ms
Wait 198 ms
Download 0 ms

URL: https://yugicardcenter.store/.well-known/ucp
Server: 172.67.222.176
Sent user-agent: UCPCheckerBot/1.0 (+https://ucpchecker.com/methodology)
Sent accept: application/json
Sent signature-agent: "https://ucpchecker.com"
Sent signature: Web Bot Auth (RFC 9421)
Got server: cloudflare
Got content-type: application/json
Got cache-control: public, max-age=3600
Got cf-ray: a516b6858d61ffb2-EWR

GET www.yugicardcenter.store/.well-known/ucp 200 OK 3.3 KB · application/json 1,850 ms

Answered.

DNS 0 ms
Connect 1 ms
TLS 60 ms
Wait 1,788 ms
Download 0 ms

URL: https://www.yugicardcenter.store/.well-known/ucp
Server: 104.21.17.57
Sent user-agent: UCPCheckerBot/1.0 (+https://ucpchecker.com/methodology)
Sent accept: application/json
Sent signature-agent: "https://ucpchecker.com"
Sent signature: Web Bot Auth (RFC 9421)
Got server: cloudflare
Got content-type: application/json
Got cache-control: public, max-age=3600
Got cf-ray: a516b6873f4657b0-EWR

Outside UCP · its other files3 requests · 3 × 200 OK3,375 ms

GET / 200 OK 434.7 KB · text/html 421 ms

Answered.

DNS 0 ms
Connect 1 ms
TLS 314 ms
Wait 73 ms
Download 32 ms

URL: https://yugicardcenter.store/
Server: 172.67.222.176
Sent user-agent: UCPCheckerBot/1.0 (+https://ucpchecker.com/methodology)
Sent signature-agent: "https://ucpchecker.com"
Sent signature: Web Bot Auth (RFC 9421)
Got server: cloudflare
Got content-type: text/html; charset=utf-8
Got cache-control: public, max-age=6, stale-while-revalidate=86400
Got cf-ray: a516b6948c494210-EWR

GET /llms.txt 200 OK 960 B · text/plain 872 ms

Answered.

DNS 0 ms
Connect 124 ms
TLS 196 ms
Wait 551 ms
Download 0 ms

URL: https://yugicardcenter.store/llms.txt
Server: 172.67.222.176
Sent user-agent: UCPCheckerBot/1.0 (+https://ucpchecker.com/methodology)
Sent accept: text/plain
Sent signature-agent: "https://ucpchecker.com"
Sent signature: Web Bot Auth (RFC 9421)
Got server: cloudflare
Got content-type: text/plain; charset=utf-8
Got cache-control: public,max-age=3600
Got cf-ray: a516b6948dcc8dd6-EWR

GET /sitemap.xml 200 OK 1,628.1 KB · text/xml 3,375 ms

Answered.

DNS 0 ms
Connect 178 ms
TLS 146 ms
Wait 2,915 ms
Download 135 ms

URL: https://yugicardcenter.store/sitemap.xml
Server: 172.67.222.176
Sent user-agent: UCPCheckerBot/1.0 (+https://ucpchecker.com/methodology)
Sent accept: application/xml,text/xml
Sent signature-agent: "https://ucpchecker.com"
Sent signature: Web Bot Auth (RFC 9421)
Got server: cloudflare
Got content-type: text/xml; charset=utf-8
Got cache-control: no-store, no-cache, must-revalidate, max-age=0, private
Got cf-ray: a516b6949c3642b2-EWR

01 PROFILEValid against the 2026-08-25 schema; keys publishedlocal

How agents reach this store. yugicardcenter.store's UCP profile (2026-08-25) declares two transports for dev.ucp.shopping: REST and MCP. One panel per transport, in the spec's words.

Capabilities

8 declared · all at 2026-08-25

Cart dev.ucp.shopping.cart

RESTMCP

Checkout dev.ucp.shopping.checkout

RESTMCP

Discountextension dev.ucp.shopping.discount

RESTMCP

Fulfillmentextension dev.ucp.shopping.fulfillment

RESTMCP

Location Lookup dev.ucp.common.location.lookup

RESTMCP

Location Search dev.ucp.common.location.search

RESTMCP

Catalog Lookup dev.ucp.shopping.catalog.lookup

RESTMCP

Catalog Search dev.ucp.shopping.catalog.search

RESTMCP

Payment handlers

1 declared

Paylink dev.boutir.payment.paylink

REST

14 operations the spec defines · 0 called

Endpointhttps://yugicardcenter.store/apis/ucp

The operations the UCP spec defines for each capability in the profile, appended to the endpoint. REST has no list call, so we can only say what our check called.

Catalog searchdev.ucp.shopping.catalog.search

POST/catalog/searchDeclared, not called

Catalog lookupdev.ucp.shopping.catalog.lookup

Not part of our public check.

POST/catalog/lookupDeclared, not called

POST/catalog/productDeclared, not called

Cartdev.ucp.shopping.cart

We don't call these: they change state.

POST/cartsDeclared, not called

GET/carts/{id}Declared, not called

PUT/carts/{id}Declared, not called

POST/carts/{id}/cancelDeclared, not called

Checkoutdev.ucp.shopping.checkout

We don't call these: they change state.

POST/checkout-sessionsDeclared, not called

GET/checkout-sessions/{id}Declared, not called

PUT/checkout-sessions/{id}Declared, not called

POST/checkout-sessions/{id}/completeDeclared, not called

POST/checkout-sessions/{id}/cancelDeclared, not called

Location searchdev.ucp.common.location.search

POST/locations/searchDeclared, not called

Location lookupdev.ucp.common.location.lookup

Not part of our public check.

POST/locations/lookupDeclared, not called

Also declared, with no operations of their own

Discountdev.ucp.shopping.discount

Extends cart and checkout. No operations of its own.

Fulfillmentdev.ucp.shopping.fulfillment

Extends catalog search and catalog lookup and checkout. No operations of its own.

MCP

10 listed · 10 of 14 the spec expects

Endpointhttps://yugicardcenter.store/apis/ucp/mcp

The tools the UCP spec defines for each capability in the profile, checked against what the store's MCP service listed when we asked (tools/list). Struck through: expected but not listed.

Catalog searchdev.ucp.shopping.catalog.search

search_catalog

Catalog lookupdev.ucp.shopping.catalog.lookup

lookup_catalogget_product

Cartdev.ucp.shopping.cart

create_cartget_cartupdate_cartcancel_cart

Checkoutdev.ucp.shopping.checkout

create_checkoutget_checkoutupdate_checkoutcomplete_checkoutcancel_checkout

Location searchdev.ucp.common.location.search

search_locations

Location lookupdev.ucp.common.location.lookup

lookup_locations

Also declared, with no operations of their own

Discountdev.ucp.shopping.discount

Extends cart and checkout. No operations of its own.

Fulfillmentdev.ucp.shopping.fulfillment

Extends catalog search and catalog lookup and checkout. No operations of its own.

No Embedded Checkout declared: checkout continues by redirect to the checkout's continue_url.

UCP profile as served 5.6 KB · 130 lines

{
    "ucp": {
        "keys": [],
        "status": "success",
        "version": "2026-08-25",
        "services": {
            "dev.ucp.common": [
                {
                    "spec": "https://ucp.dev/2026-08-25/specification/overview",
                    "schema": "https://ucp.dev/2026-08-25/services/common/rest.openapi.json",
                    "version": "2026-08-25",
                    "endpoint": "https://yugicardcenter.store/apis/ucp",
                    "transport": "rest"
                },
                {
                    "spec": "https://ucp.dev/2026-08-25/specification/overview",
                    "schema": "https://ucp.dev/2026-08-25/services/common/mcp.openrpc.json",
                    "version": "2026-08-25",
                    "endpoint": "https://yugicardcenter.store/apis/ucp/mcp",
                    "transport": "mcp"
                }
            ],
            "dev.ucp.shopping": [
                {
                    "spec": "https://ucp.dev/2026-08-25/specification/overview",
                    "schema": "https://ucp.dev/2026-08-25/services/shopping/rest.openapi.json",
                    "version": "2026-08-25",
                    "endpoint": "https://yugicardcenter.store/apis/ucp",
                    "transport": "rest"
                },
                {
                    "spec": "https://ucp.dev/2026-08-25/specification/overview",
                    "schema": "https://ucp.dev/2026-08-25/services/shopping/mcp.openrpc.json",
                    "version": "2026-08-25",
                    "endpoint": "https://yugicardcenter.store/apis/ucp/mcp",
                    "transport": "mcp"
                }
            ]
        },
        "capabilities": {
            "dev.ucp.shopping.cart": [
                {
                    "spec": "https://ucp.dev/2026-08-25/specification/cart",
                    "schema": "https://ucp.dev/2026-08-25/schemas/shopping/cart.json",
                    "version": "2026-08-25"
                }
            ],
            "dev.ucp.shopping.checkout": [
                {
                    "spec": "https://ucp.dev/2026-08-25/specification/checkout",
                    "schema": "https://ucp.dev/2026-08-25/schemas/shopping/checkout.json",
                    "version": "2026-08-25"
                }
            ],
            "dev.ucp.shopping.discount": [
                {
                    "spec": "https://ucp.dev/2026-08-25/specification/discount",
                    "schema": "https://ucp.dev/2026-08-25/schemas/shopping/discount.json",
                    "extends": [
                        "dev.ucp.shopping.cart",
                        "dev.ucp.shopping.checkout"
                    ],
                    "version": "2026-08-25"
                }
            ],
            "dev.ucp.shopping.fulfillment": [
                {
                    "spec": "https://ucp.dev/2026-08-25/specification/shopping/extensions/fulfillment/",
                    "schema": "https://ucp.dev/2026-08-25/schemas/shopping/fulfillment.json",
                    "extends": [
                        "dev.ucp.shopping.catalog.search",
                        "dev.ucp.shopping.catalog.lookup",
                        "dev.ucp.shopping.checkout"
                    ],
                    "version": "2026-08-25"
                }
            ],
            "dev.ucp.common.location.lookup": [
                {
                    "spec": "https://ucp.dev/2026-08-25/specification/common/location/lookup/",
                    "schema": "https://ucp.dev/2026-08-25/schemas/common/location_lookup.json",
                    "version": "2026-08-25"
                }
            ],
            "dev.ucp.common.location.search": [
                {
                    "spec": "https://ucp.dev/2026-08-25/specification/common/location/search/",
                    "schema": "https://ucp.dev/2026-08-25/schemas/common/location_search.json",
                    "version": "2026-08-25"
                }
            ],
            "dev.ucp.shopping.catalog.lookup": [
                {
                    "spec": "https://ucp.dev/2026-08-25/specification/catalog/lookup/",
                    "schema": "https://ucp.dev/2026-08-25/schemas/shopping/catalog_lookup.json",
                    "version": "2026-08-25"
                }
            ],
            "dev.ucp.shopping.catalog.search": [
                {
                    "spec": "https://ucp.dev/2026-08-25/specification/catalog/search/",
                    "schema": "https://ucp.dev/2026-08-25/schemas/shopping/catalog_search.json",
                    "version": "2026-08-25"
                }
            ]
        },
        "payment_handlers": {
            "dev.boutir.payment.paylink": [
                {
                    "id": "dev.boutir.payment.paylink",
                    "spec": "https://yugicardcenter.store/.well-known/ucp/payment-handler/spec",
                    "config": {
                        "description": "Create an unpaid payment link for the order. The shopper can pay through the returned payment URL."
                    },
                    "schema": "https://yugicardcenter.store/.well-known/ucp/payment-handler/schema.json",
                    "version": "2026-08-25",
                    "available_instruments": [
                        {
                            "type": "paylink"
                        }
                    ]
                }
            ]
        },
        "supported_versions": {
            "2026-04-08": "https://yugicardcenter.store/.well-known/ucp/2026-04-08",
            "2026-08-25": "https://yugicardcenter.store/.well-known/ucp/2026-08-25"
        }
    }
}

What goes in a UCP profile →Check your JSON in the Validator →Guides by store platform →

/llms.txt as served 959 B · mentions UCP

# llms.txt
# Public brief for AI agents about YuGiCard Center

# About
YuGiCard Center online store.

# Product Categories
- 5等分花嫁 TCG
- 5等分花嫁 TCG > 卡組
- 5等分花嫁 TCG > 擴充包
- 5等分花嫁 TCG > 散卡
- 5等分花嫁 TCG > 週邊
- BF BUDDY FIGHT
- Battle Spirits
- Battle Spirits > 卡組
- Battle Spirits > 擴充包
- Battle Spirits > 擴充包 > 26RBS
- Battle Spirits > 擴充包 > 26RCB
- Battle Spirits > 擴充包 > 26RDB
- Battle Spirits > 擴充包 > BSC系列
- Battle Spirits > 擴充包 > CB系列
- Battle Spirits > 擴充包 > 正篇系列
- Battle Spirits > 散卡
- Battle Spirits > 散卡 > Bs52
- Battle Spirits > 福袋
- Battle Spirits > 禮盒
- Battle Spirits > 週邊

# Policies
- Return policy: https://yugicardcenter.store/returnpolicy
- Terms: https://yugicardcenter.store/terms
- Privacy: https://yugicardcenter.store/privacy

# UCP
- Discovery profile: https://yugicardcenter.store/.well-known/ucp

Is yugicardcenter.store your store?

Claim it with one DNS record.

Claim this store Send an agent to shop here ↗

Status badge

Markdown ·

[![UCP Status](https://ucpchecker.com/badge/yugicardcenter.store)](https://ucpchecker.com/status/yugicardcenter.store)

Questions

Can UCP agents buy from yugicardcenter.store?

Through its REST and MCP services, an agent can search the catalogue, build a cart and start a checkout. The service answered our check. This is what the store declares and what our check reached; an observed agent run shows how far an agent actually gets.

Is yugicardcenter.store ready for UCP agents?

yugicardcenter.store publishes a valid UCP profile and scores 96/100 (grade A). 1 thing to fix: cryptographic message signing is not yet enabled.

What is a UCP profile?

The JSON file a store publishes at /.well-known/ucp to tell UCP agents which services it offers, how to call them and how it takes payment. The spec calls it the business profile. yugicardcenter.store's is 3.3 KB, written for UCP 2026-08-25. What goes in a UCP profile.

How was yugicardcenter.store checked?

With public requests on 28 Oct 2026: we read /.well-known/ucp and robots.txt, validated the profile against UCP 2026-08-25, checked that its spec and schema links resolve, and called its REST and MCP service. No sign-in and no purchase. How we check.