UCP Checker
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Every UCP release, and what changed

4 releases so far, each named by its date. What each one changed in a store's profile, checked against the spec's own schemas at each release tag, and how many verified stores follow it today.

  1. 2026-08-2525 August 2026

    Shopping, payment and common

    Current
    • The spec splits into shopping, payment and common parts: 10 capability names become 17.
    • New: 3-D Secure authentication, split payments, payment terms, store location search and lookup, loyalty, and permalinks.
    • signing_keys becomes keys, a JWK Set beside ucp.
    • Each capability in a store's profile names its schema again.
    • AP2 mandates move to dev.ucp.common.payment.ap2_mandate.
    58% of verified stores
  2. 2026-04-088 April 2026

    The catalogue, and older versions

    Supported
    • Catalogue search and lookup arrive as capabilities.
    • supported_versions lets a store point agents on older releases to a profile for each.
    42% of verified stores
  3. 2026-01-2323 January 2026

    Store profiles and platform profiles

    Supported
    • Profiles split in two: a store's own, at /.well-known/ucp, and a platform's, which agents name in their requests.
    • Payment handlers move into ucp.payment_handlers and become required; capabilities become optional.
    • A store's profile no longer needs spec and schema links on its entries; platform profiles still do.
    <1% of verified stores
  4. 2026-01-1111 January 2026

    The first release

    Supported
    • A profile at /.well-known/ucp: ucp with version, services and capabilities, each capability with its spec and schema.
    • Payment handlers under payment.handlers, signing_keys at the root.
    • Four transports: REST, MCP, A2A and Embedded.
    <1% of verified stores

What a profile needs, release by release

2026-01-112026-01-232026-04-082026-08-25
required in ucpversion, services, capabilitiesversion, services, payment_handlerssamesame
payment handlerspayment.handlers, optionalucp.payment_handlers, requiredsamesame
signing keyssigning_keys, at the rootsamesamekeys, at the root
links on a store's entriesspec and schema on capabilitiesnone requirednone requiredschema on capabilities
older versions––supported_versionssupported_versions
transportsREST, MCP, A2A and Embedded in every release

Food and Lodging

Each now has its own technical council: Food since 16 July 2026, Lodging since 11 August 2026. Neither has published a capability yet, so stores and our checks still use the shopping capabilities. Verticals

Check a profile against any release

The UCP Validator reads the release a profile declares and applies its rules.

Open the UCP Validator

Shares are of verified stores in the directory, from each store's latest check. Read 18 October 2026.

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