practical.stream
verified_user Multi-version UCP compliance, backward compatibility & transport audit
schedule Last scanned 5/4/2026
Conformance
49%Capability
100%Coverage
24%Backward Compat
0%Negative
44%Transport
100%Latency
99%Audit Details
Cache-Control max-age is within recommended bounds
Completed in 33ms
Profile response advertises cache headers
Completed in 74ms
Profile declares at least the checkout capability
Completed in 65ms
Capability version strings are valid ISO dates
Completed in 66ms
Profile response Content-Type is application/json
Completed in 74ms
Discovery endpoint exposes CORS headers
Discovery response is missing Access-Control-Allow-Origin header
Profile is served over HTTPS
Completed in 54ms
Two consecutive profile fetches return identical bodies
Completed in 104ms
Signing JWKs use only allowed kty/crv values
Profile declares no signing_keys array — the field is optional per the UCP spec, but agents cannot verify signed payloads from this merchant
No duplicate capability entries (same name + version)
Completed in 65ms
OpenAPI servers[] URL is reachable
Completed in 332ms
Business profile has a valid structure
Business profile failed schema validation
Merchant responses are signed with the published signing_keys
Profile declares no signing_keys; nothing to verify against. DISC-0002 tracks absence separately.
robots.txt allows AI agents to read the UCP profile
Completed in 108ms
All declared schema URLs use HTTPS
(bindings ?? []) is not iterable
Signing keys are importable via Web Crypto
Profile declares no signing_keys array — the field is optional per the UCP spec, but agents cannot verify signed payloads from this merchant
Profile advertises well-formed signing keys
Profile declares no signing_keys array — the field is optional per the UCP spec, but agents cannot verify signed payloads from this merchant
Service binding transports are in the allowed set
(bindings ?? []) is not iterable
Profile declares a ucp.version string
Completed in 66ms
Profile ucp.version is one the grader recognizes
Completed in 74ms
Profile is served at the canonical .well-known/ucp path
Completed in 113ms
Declared capabilities match operations in the OpenAPI
No OpenAPI operations available to cross-check
Capability JSON Schemas declare a modern $schema draft
Capability-level JSON Schemas are well-formed
OpenAPI components.schemas has no orphans
Service-level OpenAPI document is valid OpenAPI 3.x
OpenAPI document declares zero path operations
Every OpenAPI operation declares a 2xx JSON response schema
OpenAPI declares no operations
Every $ref referenced schema document is reachable
Completed in 1800ms
All declared schema URLs return 200
Cancel session response matches the OpenAPI schema
Could not create session: 405
Create session response matches the OpenAPI schema
Expected 2xx, got 405
Discovery profile matches the published JSON Schema
Completed in 64ms
Get session response matches the OpenAPI schema
Could not create session: 405
Update session response matches the OpenAPI schema
Could not create session: 405
Canceling a session twice with the same idempotency key is idempotent
createSession returned status=405
Cancel a checkout session
createSession returned 405
Create checkout session with defaults
createSession returned status=405
Repeated createSession with same idempotency key returns same session
First create failed: 405
Create session then set shipping address
createSession returned 405
Retrieve a checkout session by id
createSession returned 405
Reusing an Idempotency-Key with a different body must be rejected
First createSession returned status=405
update_checkout is idempotent on replay and rejects conflicting replays
createSession returned status=405
Select a shipping method on a checkout session
createSession returned 405
Catalog capability advertised for product lookup
Profile does not declare dev.ucp.shopping.catalog.lookup
Catalog capability is declared
Profile does not declare dev.ucp.shopping.catalog.search
Checkout capability is declared and reachable
Completed in 65ms
Fulfillment capability is declared
Profile does not declare dev.ucp.shopping.fulfillment