Maui.RevenueCat.InAppBilling

A .NET MAUI wrapper library for RevenueCat in-app purchases. Provides a unified C# API that abstracts away the need for you to use platform-specific code from Android and iOS native bindings.

Features

• Unified API for iOS, Android and Mac Catalyst in-app purchases
• Subscription and one-time purchase support
• User authentication (anonymous and identified users)
• Subscription status and entitlement checking
• Trial/intro discount eligibility
• Subscriber attributes management
• Test Store test_… keys work in Release builds on iOS - the shipped xcframework is built from source with BYPASS_SIMULATED_STORE_RELEASE_CHECK, so it does not force-close the app
• Stub implementation for Windows (for development convenience)

Installation

dotnet add package Kebechet.Maui.RevenueCat.InAppBilling

Quick Start

1. Register the service

In your MauiProgram.cs:

builder.Services.AddRevenueCatBilling();

2. Inject and initialize

In App.xaml.cs, inject IRevenueCatBilling and initialize in OnStart():

public partial class App : Application
{
    private readonly IRevenueCatBilling _revenueCat;

    public App(IRevenueCatBilling revenueCat)
    {
        InitializeComponent();
        _revenueCat = revenueCat;
    }

    protected override void OnStart()
    {
        var revenueCatApiKey = string.Empty;

#if __ANDROID__
        revenueCatApiKey = "<your-android-api-key>";
#elif __IOS__
        revenueCatApiKey = "<your-ios-api-key>";
#endif

        _revenueCat.Initialize(revenueCatApiKey);
        base.OnStart();
    }
}

Important: Initialize must be called in OnStart(), not in the constructor.

Test Store API keys

RevenueCat's Test Store lets you exercise the full purchase flow without configuring App Store Connect / Play Console products. Test Store keys start with test_.

This wrapper ships an iOS xcframework built from source with the BYPASS_SIMULATED_STORE_RELEASE_CHECK Swift compilation flag, so a test_… key works on iOS Release builds too — it does not force-close the app. No code changes are required on your side; just pass the test_… key to Initialize(...).

On Android no such rebuild is needed: the RevenueCat SDK ships as a normal AAR (Kotlin bytecode), so its test-key check runs against the consuming app's build at runtime rather than being compiled into the library — a prebuilt AAR doesn't carry the always-on guard the prebuilt iOS framework did. Test Store support does require RevenueCat Android SDK 9.9.0+; this binding ships upstream SDK 10.16.1 (binding package 10.16.1), so test_… keys work out of the box (see issue #95, resolved by that SDK bump). The same "don't ship a test_ key to production" guidance applies on both platforms.

See src/Maui.RevenueCat.iOS/README.md for the build-time details and issue #116 for context.

API Reference

Initialization & State

Method	Description
Initialize(string apiKey)	Initialize RevenueCat with your platform-specific API key
IsInitialized()	Check if the SDK has been initialized
IsAnonymous()	Check if current user is anonymous
GetAppUserId()	Get the current user ID

Offerings & Products

Method	Description
GetOfferings(bool forceRefresh = false)	Fetch available offerings and packages
CheckTrialOrIntroDiscountEligibility(List<string> identifiers)	Check eligibility for trials/intro pricing. Apple platforms only (iOS and Mac Catalyst); throws NotImplementedException on Android

Purchases

Method	Description
PurchaseProduct(PackageDto package)	Initiate a purchase flow
GetActiveSubscriptions()	Get list of active subscription identifiers
GetAllPurchasedIdentifiers()	Get all purchased product identifiers
GetPurchaseDateForProductIdentifier(string productSku)	Get purchase date for a specific product
RestoreTransactions()	Restore previous purchases

User Management

Method	Description
Login(string appUserId)	Log in an identified user
Logout()	Log out and create anonymous user
GetCustomerInfo()	Get current customer info and entitlements
GetManagementSubscriptionUrl()	Get URL for subscription management

Subscriber Attributes

Method	Description
SetEmail(string email)	Set user's email
SetDisplayName(string name)	Set user's display name
SetPhoneNumber(string phone)	Set user's phone number
SetAttributes(IDictionary<string, string> attributes)	Set custom attributes

Example: Complete Purchase Flow

public class PurchaseService
{
    private readonly IRevenueCatBilling _revenueCat;

    public PurchaseService(IRevenueCatBilling revenueCat)
    {
        _revenueCat = revenueCat;
    }

    public async Task<bool> PurchaseSubscription()
    {
        var offerings = await _revenueCat.GetOfferings();
        if (offerings.Count == 0)
            return false;

        var defaultOffering = offerings.FirstOrDefault(o => o.IsCurrent);
        var monthlyPackage = defaultOffering?.AvailablePackages
            .FirstOrDefault(p => p.Identifier == "monthly");

        if (monthlyPackage == null)
            return false;

        var result = await _revenueCat.PurchaseProduct(monthlyPackage);

        if (result.IsSuccess)
        {
            // Purchase successful
            return true;
        }

        if (result.ErrorStatus == PurchaseErrorStatus.PurchaseCancelledError)
        {
            // User cancelled - not an error
            return false;
        }

        // Handle other errors
        Console.WriteLine($"Purchase failed: {result.ErrorStatus}");
        return false;
    }

    public async Task<bool> HasActiveSubscription(string entitlementId)
    {
        var customerInfo = await _revenueCat.GetCustomerInfo();
        return customerInfo?.ActiveSubscriptions
            .Any(e => e == entitlementId) ?? false;
    }
}

Platform Support

Platform	Support
Android	Full implementation
iOS	Full implementation
Windows	Stub (returns defaults)
MacCatalyst	Full implementation (shares the iOS implementation)

Stub implementations return:

• true for boolean methods
• Empty collections for list methods
• string.Empty for string methods
• null for nullable types

This allows you to build and test on Windows/Mac without platform conditionals.

Error Handling

The library follows a non-throwing approach for runtime errors:

• Exceptions are thrown only for developer mistakes (e.g., calling methods before Initialize())
• Runtime errors (network issues, store problems, etc.) return:
  • ErrorStatus in result DTOs (e.g., PurchaseResultDto.ErrorStatus)
  • Empty collections for list returns
  • null for nullable types

This design ensures your app never crashes due to store-related issues.

Common Error Codes

Error	Description
PurchaseCancelledError	User cancelled the purchase
StoreProblemError	Issue with the app store
NetworkError	Network connectivity issue
ProductAlreadyPurchasedError	Product was already purchased
PaymentPendingError	Payment is pending (e.g., awaiting approval)

See PurchaseErrorStatus for the complete list.

Credits

• Native bindings for Android and iOS inspired by thisisthekap's Xamarin bindings
• Abstraction layer based on RevenueCatXamarin by BillFulton

Contributing

Feel free to create an issue or pull request. For major changes, please open an issue first to discuss your proposal - large PRs without prior discussion may be rejected.

License

This project is licensed under the MIT License.