Tracking: Apple 12-month commitment (`:monthly`) billing plans unavailable in KMP — bundled `libRevenueCat.a` is built with Swift 6.1.2

[danego61]

• I have updated Purchases SDK to the latest version

• I have read the Contribution Guidelines

• I have searched the Community

• I have read docs.revenuecat.com

• I have searched for existing GitHub issues

  Describe the bug

  Apple's new "Monthly Subscriptions with a 12-Month Commitment" billing plans (<product_id>:monthly products, docs) never appear in offerings
  on iOS when using purchases-kmp. Offerings only return the standard packages (e.g. $rc_annual, $rc_weekly); the package configured with the :monthly product is silently dropped.

  I'm aware the docs say "Available in the native iOS SDK in versions 5.76.0+, support in the hybrid SDKs is coming soon" — purchases-kmp 3.3.0 already bundles purchases-ios 5.80.3 (which satisfies 5.76+), so I dug into why
  it still doesn't work and am filing this as a tracking issue with the root cause identified, since I couldn't find an existing one.

  Root cause: the installment/billing-plan code path in purchases-ios is gated behind a compile-time check, and the pre-compiled static library shipped inside the KMP klibs is built with an older Swift toolchain, so that code
  path is compiled out entirely:

  1. The code gate. In purchases-ios (ProductsFetcherSK2.swift, also InstallmentsInfoFactory.swift), all billing-plan handling is wrapped in:

     // Billing plans were introduced with Xcode 26.5, which shipped with Swift version 6.3.2.
     #if compiler(>=6.3.2)

  2. The shipped binary. The libRevenueCat.a inside purchases-kmp-kn-core-iosarm64-3.3.0-cinterop-RevenueCat.klib (verified against Maven Central's published checksum, sha256
     eaaf9204869cffb554f39207456557f9417ecae69fdedeabc34202d86d6cfdc6) is stamped with Apple Swift version 6.1.2 (464 occurrences via strings, no other version). A symbol lookup via nm confirms there are zero references to
     StoreKit's Product.SubscriptionInfo.PricingTerms — the gated code physically doesn't exist in the binary. (RevenueCat's own ungated RCInstallmentsInfo / RCBillingPlanType types are present, so the cinterop API surface
     exists but can never be populated on the Apple side.)

  3. The CI configuration. .circleci/config.yml builds and publishes the KMP artifacts with the xcode16 executor (xcode: 16.4.0 → Swift 6.1.2), including the publish job.

  Since 6.1.2 < 6.3.2, populateSK2CompoundProductsIfSupported compiles to a no-op, the :monthly StoreKit product is never created, and OfferingsFactory.createOffering silently drops the package via compactMap. Using Xcode
  26.5 locally does not help, because the consuming app links the pre-compiled .klib artifact from Maven Central.

  I do realize the Xcode 16.4.0 pin is deliberate — the comment above the xcode16 executor explains it (consuming-app minimum Xcode version / RevenueCatUI in 3.0.1 references private SwiftUI symbols and SwiftUICore; iOS host link fails with "not an allowed client of SwiftUICore" + undefined SwiftUI internal symbols #859, Kotlin/Native's supported Xcode versions, and CircleCI's image retention policy).
  So this is likely non-trivial to fix and may need to wait for Kotlin/Native to support Xcode 26.5, or a dual-artifact strategy. Filing this so there's a tracking issue for KMP users, since this feature cannot be worked around on
  the app side.

  Environment

  1. Platform: iOS (Kotlin Multiplatform)
  2. SDK version: purchases-kmp 3.3.0 (bundles purchases-ios 5.80.3)
  3. OS version: iOS 26.4+
  4. IDE: Android Studio & Xcode
  5. Xcode version (local): 26.5
  6. Device and/or emulator/simulator:
     • Device
     • Emulator/simulator
  7. Environment:
     • Sandbox
     • TestFlight
     • Production
  8. How widespread is the issue: 100% of KMP iOS apps trying to use Apple installment/commitment billing plans.

  Steps to reproduce, with expected vs. actual behavior

  1. In App Store Connect, add a "Monthly with 12-Month Commitment" billing plan to an annual subscription product.
  2. In the RevenueCat dashboard, create the :monthly product (12-months-commitment option enabled) and attach it to a package in the current offering.
  3. In a KMP app on an iOS 26.4+ device, call Purchases.sharedInstance.awaitOfferings() (or getOfferings).

  Expected: the offering contains the package with the :monthly installment product, with populated installments info.

  Actual: the package is missing from availablePackages; only the base packages are returned.

  Suggested fix

  Build and publish the KMP iOS artifacts (the static Swift library embedded in the Kotlin/Native klibs) with Xcode 26.5+ / Swift 6.3.2+, once the constraints above allow it. Happy to provide any additional info or test a snapshot
  build.

[fire-at-will]

Hey @danego61, thanks for reporting! We'll take a look at this and let you know when support for 12-monthly commitment billing plans in the KMP SDK is ready!