Checkout MCP and Cart MCP now support UCP buyer consent
Shopify developer change
MerchantDiff detected this entry in Shopify's official developer changelog on October 16, 2026.
This Shopify update is categorized as UCP, New.
What changed
Storefronts now list dev.ucp.shopping.buyer_consent in their discovery profiles at /.well-known/ucp. This extension applies to both cart and checkout. If your agent profile negotiates dev.ucp.shopping.buyer_consent on UCP 2026-08-25: Checkout MCP and Cart MCP responses include a buyer.consent object. buyer.consent lists each consent purpose that the shop supports, its current state, a description, and links to the shop’s policies. Shopify storefronts advertise at least these consent purposes: dev.ucp.consent.analytics dev.ucp.consent.preferences dev.ucp.consent.sale_or_sharing dev.ucp.consent.marketing, with email and sms segments You can send the buyer’s consent choices when you create, update, or complete a cart or checkout.
Who is affected
Platforms and agents that use Checkout MCP or Cart MCP with UCP 2026-08-25 and negotiate the dev.ucp.shopping.buyer_consent extension are affected. Integrations that don’t declare this extension, or that negotiate an earlier UCP version, aren’t affected.
What action may be needed
Declare the dev.ucp.shopping.buyer_consent extension at version 2026-08-25 in your agent profile. When you render cart or checkout, show each consent option to the buyer using the shop’s description and policy links from buyer.consent. When the buyer makes a choice, send that choice back on cart and checkout create, update, or complete calls, and set source: "platform" only for choices that the buyer actually made during your flow.
Use the official Shopify entry below as the source of truth for technical implementation details, affected APIs, migration instructions and deadlines.
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