SubscriptionContractCalculation API now available in early access
Shopify developer change
MerchantDiff detected this entry in Shopify's official developer changelog on July 27, 2026.
This Shopify update is categorized as API, New, GraphQL Admin API, 2026-10.
What changed
Contract edits now run through the same C1 checkout engine that powers Checkout, Draft Orders, and subscription billing attempts, instead of the bespoke SubscriptionDraft engine that ran in parallel to checkout. The previous workflow required a dozen-plus stateful mutations across the draft lifecycle to edit a single contract (create draft → add line → update line → remove line → add discount → apply code → update delivery → commit). The new API consolidates this into three calculate operations plus a shared commit: Calculate: submit the desired contract state in a single mutation: subscriptionContractCreateCalculate, subscriptionContractUpdateCalculate, or subscriptionBillingCycleContractEditCalculate. Poll: the calculate mutation returns a SubscriptionContractCalculationPending response.
Who is affected
This applies to any app that creates, updates, or edits subscription contracts using the SubscriptionDraft object. Apps that only read contracts or manage contract status (through subscriptionContractActivate, subscriptionContractPause, and similar mutations) are unaffected. Status is still set through those dedicated mutations, not the calculation input.
What action may be needed
Action is required to adopt the new capabilities. The SubscriptionDraft object will be deprecated once the new API reaches general availability on 2026-10; it will remain available but won't support the new capabilities. Don't build production integrations until 2026-10 is stable. We've written a full migration guide to support your move to the new API.
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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