iOS `subscriptionGroupId` is only present on `subscriptionInfoIOS`, which is deprecated

[lucaslcode]

iOS subscriptionGroupId is only present on subscriptionInfoIOS, which is deprecated.

This is required for isEligibleForIntroOfferIOS.

Workaround: use the deprecated field. This is fine, but will be a problem if it is removed in a later version.

[hyochan]

Thanks for pointing this out.

subscriptionInfoIOS was deprecated intentionally when OpenIAP introduced the standardized subscriptionOffers field. That migration path is meant to replace the old platform-specific offer structures (introductoryOffer, promotionalOffers, discountsIOS) with a cross-platform offer model.

subscriptionGroupId is a bit different: it is subscription-level iOS metadata, and it is also useful as the input for isEligibleForIntroOfferIOS. For now, the supported workaround is to keep reading product.subscriptionInfoIOS?.subscriptionGroupId even though the containing field is deprecated.

I do not think we should un-deprecate subscriptionInfoIOS or move back toward the old platform-specific offer model. If we expose a non-deprecated path, it should probably be a separate iOS subscription product field such as subscriptionGroupIdIOS, followed by the normal GQL type generation and SDK sync.

Leaving this open as an API design / feature tracking issue rather than treating it as a bug.

[hyochan]

One clarification before deciding whether to close this:

subscriptionGroupId does not have to come from subscriptionInfoIOS. isEligibleForIntroOfferIOS(groupID) accepts the App Store subscription group ID directly, so apps can pass a known group ID from App Store Connect or app configuration.

Because subscriptionInfoIOS was intentionally deprecated as part of the migration to the standardized subscriptionOffers model, I am leaning toward not adding a replacement product field unless there is a concrete use case where the group ID must be derived from fetched product data.

Does passing/storing the subscription group ID directly work for your use case, or do you specifically need it exposed on fetched products? If you need it on the product object, can you share the reason so we can evaluate whether a non-deprecated subscriptionGroupIdIOS field is worth adding?

[lucaslcode]

Sorry for the slow response.

I simply don't think it's a good idea to hard-code sub group ids. We get subscription SKUs from our backend, and they are different in dev and staging environments, for example. We could of course also store the subscription group ids, but it's more manual reconciliation with app store when the data is available via api.

[hyochan]

PR #165 has been merged. ProductSubscriptionIOS.subscriptionGroupIdIOS will be included in the next release, so apps can read the App Store subscription group ID directly without relying on deprecated subscriptionInfoIOS.subscriptionGroupId.