SubscriptionContractCalculation API now available in early access

The new SubscriptionContractCalculation object on the GraphQL Admin API is now available in early access on the 2026-10 release candidate API version. It’s the successor to the GraphQL Admin API’s SubscriptionDraft object for creating, updating, and editing subscription contracts, replacing the multi-step draft workflow with a stateless calculate → poll → commit lifecycle that runs through Shopify’s unified checkout engine. Moving contract edits onto the unified checkout engine keeps calculations consistent with checkout, one calculate mutation replaces 12+ draft mutations, and new checkout ca