flutter_windows_iap

Flutter plugin for Microsoft Store in-app purchases on Windows. Wraps Windows.Services.Store.StoreContext via a C++/WinRT platform channel — no third-party dependencies, no server-side validation required for non-consumables.

Platform	Supported
Windows	✅
Android / iOS / macOS / Linux / Web	❌

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Features

Method	Description
queryProducts(skuIds)	Fetch product metadata (title, description, price) for one or more Store SKU IDs
purchase(skuId)	Open the native Microsoft Store purchase dialog for a single SKU
restorePurchases()	Return all owned non-consumable SKU IDs for the current Microsoft account

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Requirements

• Windows 10 version 1607 (build 14393) or later — minimum for Windows.Services.Store
• App must be packaged as MSIX and distributed through the Microsoft Store

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Installation

dependencies:
  flutter_windows_iap: ^0.1.0

This plugin only activates on Windows; it is safe to include in a multi-platform pubspec.yaml as long as your code guards IAP calls with a platform check.

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Usage

1. Guard platform calls

import 'dart:io' show Platform;
import 'package:flutter_windows_iap/flutter_windows_iap.dart';

final iap = Platform.isWindows ? FlutterWindowsIap.instance : null;

2. Query product details

Call this on the paywall screen to display localised titles and prices. Unknown SKU IDs are silently omitted by the Store.

final products = await iap!.queryProducts(['rm_ads', 'pu_custom']);
for (final p in products) {
  print('${p.title}  ${p.formattedPrice}  (${p.currencyCode})');
}

3. Purchase

final result = await iap!.purchase('rm_ads');

switch (result.status) {
  case WinIapPurchaseStatus.succeeded:
    // SKU is now owned — grant the entitlement.
    break;
  case WinIapPurchaseStatus.alreadyPurchased:
    // User already owns this — grant entitlement silently.
    break;
  case WinIapPurchaseStatus.userCancelled:
    // User dismissed the Store dialog — no action needed.
    break;
  case WinIapPurchaseStatus.failed:
    final code = result.extendedError?.toRadixString(16) ?? '?';
    print('Purchase failed: HRESULT 0x$code');
    break;
}

4. Restore on launch

Always call this at app startup to reinstate entitlements for users who reinstall or switch devices.

final owned = await iap!.restorePurchases();
// owned is a List<String> of SKU IDs the current account has purchased.
if (owned.contains('rm_ads')) {
  removeAds();
}

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Models

WinIapProduct

Field	Type	Description
skuId	String	Microsoft Store product ID
title	String	Localised product title
description	String	Localised product description
formattedPrice	String	Localised price string, e.g. "$0.99"
currencyCode	String	ISO 4217 code, e.g. "USD"

WinIapPurchaseResult

Field	Type	Description
skuId	String	The SKU that was purchased
status	WinIapPurchaseStatus	succeeded, alreadyPurchased, userCancelled, or failed
extendedError	int?	HRESULT from RequestPurchaseAsync when status is failed

WinIapPurchaseStatus

Value	Meaning
succeeded	Purchase completed; SKU is now owned
alreadyPurchased	Non-consumable was already owned by this account
userCancelled	User closed the Store dialog without purchasing
failed	Store returned an error; check extendedError for the HRESULT

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Error handling

All three methods throw a PlatformException if the Store layer itself fails (e.g. the Store service is unavailable, or IInitializeWithWindow fails).

try {
  final result = await iap!.purchase('rm_ads');
  // ...
} on PlatformException catch (e) {
  // e.code    == 'STORE_ERROR'
  // e.message == WinRT error message
  // e.details == HRESULT as int (when available)
}

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Microsoft Store setup

1. In Partner Center, open your app submission.
2. Under In-app products, create a Durable add-on for each SKU.
3. Note the Store ID (e.g. 9NBLGGH4TNMP) — this is the skuId you pass to the plugin.
4. During development, use the Store testing guide to test purchases without real charges.

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Limitations

• Non-consumables (Durable add-ons) only. Consumable and subscription add-ons are not yet supported; calling purchase on one will return failed.
• Requires MSIX packaging. Windows.Services.Store is unavailable in unpackaged Win32 apps.
• No offline license verification. License state is always fetched live from the Store; there is no local cache.

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License

MIT — see LICENSE.