From d67327c1ef5b4aaaf1f61c086064b21ca21d52d5 Mon Sep 17 00:00:00 2001
From: Jean-Emmanuel BAILLAT <baillatjean-emmanuel@hotmail.com>
Date: Sun, 19 Jul 2026 19:50:57 +0200
Subject: [PATCH] fix: expose monthly equivalent display text

---
 README.md                                     |  1 +
 .../KapuschStoreKit2Interop/Interop.swift     | 20 ++++++++++++++++++-
 .../StoreKit2BillingClient.cs                 |  3 ++-
 .../StoreKitNativeInterop.iOS.cs              |  6 +++++-
 .../nuget-readme.md                           |  1 +
 5 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/README.md b/README.md
index fe5d81a..2a053b0 100644
--- a/README.md
+++ b/README.md
@@ -10,6 +10,7 @@ Public OSS repository that packages a StoreKit 2 iOS interop wrapper into a cons
 
 A NuGet package that:
 - provides a minimal managed API for StoreKit 2 purchase and restore flows;
+- exposes store-formatted subscription prices plus an optional annual-to-monthly equivalent formatted with StoreKit's native price style;
 - redistributes the native wrapper `xcframework` inside the `.nupkg`;
 - injects the wrapper into consuming apps through `buildTransitive` `NativeReference`.
 
diff --git a/src/Kapusch.StoreKit2ApisForiOSComponents/Native/iOS/KapuschStoreKit2Interop/Sources/KapuschStoreKit2Interop/Interop.swift b/src/Kapusch.StoreKit2ApisForiOSComponents/Native/iOS/KapuschStoreKit2Interop/Sources/KapuschStoreKit2Interop/Interop.swift
index 59915d1..a76f9e3 100644
--- a/src/Kapusch.StoreKit2ApisForiOSComponents/Native/iOS/KapuschStoreKit2Interop/Sources/KapuschStoreKit2Interop/Interop.swift
+++ b/src/Kapusch.StoreKit2ApisForiOSComponents/Native/iOS/KapuschStoreKit2Interop/Sources/KapuschStoreKit2Interop/Interop.swift
@@ -51,6 +51,7 @@ private struct OfferMetadataPayload: Codable {
   let introOfferDays: Int?
   let currentPrice: Decimal
   let currentPriceDisplayText: String
+  let monthlyEquivalentPriceDisplayText: String?
 }
 
 private final class PurchaseCallbackContext: @unchecked Sendable {
@@ -226,6 +227,19 @@ private func totalDays(for offer: Product.SubscriptionOffer?) -> Int? {
   return unitValue * max(offer.periodCount, 1)
 }
 
+private func monthlyEquivalentPriceDisplayText(
+  for product: Product,
+  subscription: Product.SubscriptionInfo
+) -> String? {
+  guard subscription.subscriptionPeriod.unit == .year,
+    subscription.subscriptionPeriod.value == 1 else {
+    return nil
+  }
+
+  let monthlyPrice = product.price / Decimal(12)
+  return monthlyPrice.formatted(product.priceFormatStyle)
+}
+
 private struct PromotionalOfferInput {
   let offerId: String
   let keyId: String
@@ -652,7 +666,11 @@ public func kstorekit2_offer_metadata_start(
             isEligibleForIntroOffer: isEligibleForIntroOffer,
             introOfferDays: introOfferDays,
             currentPrice: product.price,
-            currentPriceDisplayText: product.displayPrice
+            currentPriceDisplayText: product.displayPrice,
+            monthlyEquivalentPriceDisplayText: monthlyEquivalentPriceDisplayText(
+              for: product,
+              subscription: subscription
+            )
           )
         )
       }
diff --git a/src/Kapusch.StoreKit2ApisForiOSComponents/StoreKit2BillingClient.cs b/src/Kapusch.StoreKit2ApisForiOSComponents/StoreKit2BillingClient.cs
index 849458b..3dbc61e 100644
--- a/src/Kapusch.StoreKit2ApisForiOSComponents/StoreKit2BillingClient.cs
+++ b/src/Kapusch.StoreKit2ApisForiOSComponents/StoreKit2BillingClient.cs
@@ -17,7 +17,8 @@ public sealed record StoreKitOfferMetadata(
   bool IsEligibleForIntroOffer,
   int? IntroOfferDays,
   decimal? CurrentPrice,
-  string? CurrentPriceDisplayText
+  string? CurrentPriceDisplayText,
+  string? MonthlyEquivalentPriceDisplayText = null
 );
 
 /// <summary>
diff --git a/src/Kapusch.StoreKit2ApisForiOSComponents/StoreKitNativeInterop.iOS.cs b/src/Kapusch.StoreKit2ApisForiOSComponents/StoreKitNativeInterop.iOS.cs
index c82c086..ffdfc04 100644
--- a/src/Kapusch.StoreKit2ApisForiOSComponents/StoreKitNativeInterop.iOS.cs
+++ b/src/Kapusch.StoreKit2ApisForiOSComponents/StoreKitNativeInterop.iOS.cs
@@ -33,6 +33,9 @@ internal sealed class StoreKitOfferMetadataPayload
 
 	[JsonPropertyName("currentPriceDisplayText")]
 	public string? CurrentPriceDisplayText { get; init; }
+
+	[JsonPropertyName("monthlyEquivalentPriceDisplayText")]
+	public string? MonthlyEquivalentPriceDisplayText { get; init; }
 }
 
 internal static unsafe partial class StoreKitNativeInterop
@@ -622,7 +625,8 @@ private static IReadOnlyList<StoreKitOfferMetadata> ParseOfferMetadata(string? p
 					item.IsEligibleForIntroOffer,
 					item.IntroOfferDays,
 					item.CurrentPrice,
-					item.CurrentPriceDisplayText
+					item.CurrentPriceDisplayText,
+					item.MonthlyEquivalentPriceDisplayText
 				))
 				.ToArray();
 		}
diff --git a/src/Kapusch.StoreKit2ApisForiOSComponents/nuget-readme.md b/src/Kapusch.StoreKit2ApisForiOSComponents/nuget-readme.md
index 94e6b31..856f7db 100644
--- a/src/Kapusch.StoreKit2ApisForiOSComponents/nuget-readme.md
+++ b/src/Kapusch.StoreKit2ApisForiOSComponents/nuget-readme.md
@@ -5,3 +5,4 @@
 - Target framework: `net10.0-ios`
 - Native wrapper: `kstorekit2.xcframework`
 - Native injection: `buildTransitive` `NativeReference`
+- Offer metadata: store-formatted current price and optional monthly equivalent for one-year subscriptions