influto (Flutter)

Influencer attribution + store-direct purchase validation for Flutter. Pure Dart — only http + shared_preferences. Mirrors the InfluTo React Native SDK and the canonical contract.

Prerequisites

You need a free InfluTo account — sign up at https://influ.to, create your app in the dashboard, and copy your API key (it starts with it_). For store-direct purchase validation / auto-capture, also add your Apple/Google store credentials to the app in the dashboard.

Install

dependencies:
  influto: ^1.0.0

Quick start

import 'package:influto/influto.dart';

await InfluTo.instance.initialize(const InfluToConfig(
  apiKey: 'it_live_...',
  debug: true,
  // OPTIONAL: wire RevenueCat (no hard dependency). The SDK calls it with
  // {influto_code, influto_referral:"true"} on attribution / setReferralCode.
  // revenueCatHook: (attrs) => Purchases.setAttributes(attrs),
));

final attr = await InfluTo.instance.checkAttribution();
if (attr.attributed) print('Referred by ${attr.referralCode}');

await InfluTo.instance.identifyUser('user_123');
await InfluTo.instance.trackEvent(
  const TrackEventOptions(eventType: 'paywall_viewed', appUserId: 'user_123'),
);

// Manual promo-code entry
final res = await InfluTo.instance.applyCode('FITGURU30', appUserId: 'user_123');

// Store-direct purchase (only if NOT using RevenueCat). The host obtains the proof
// from its own IAP layer (in_app_purchase / purchases_flutter) and passes it in:
//   iOS:     signedTransaction = details.verificationData.serverVerificationData      // StoreKit2 JWS
//   Android: purchaseToken     = (details as GooglePlayPurchaseDetails)
//                                  .billingClientPurchase.purchaseToken               // raw Play token
await InfluTo.instance.reportPurchase(platform: 'android', purchaseToken: token);

reportPurchase defaults referralCode to the SDK-stored influto_code, so the first transaction binds to the referral. For renewals/refunds to attribute, also set StoreKit2 appAccountToken (iOS) / Play obfuscatedAccountId (Android) at purchase time. For Android one-time / consumable products, also pass productId (+ price/currency from ProductDetails) so the purchase routes to one-time validation.

Premium access (checkAccess)

checkAccess is a server-authoritative premium-access check that works for both RevenueCat and store-direct apps. It powers platform-independent comp — e.g. a free-access code that grants entitlement without a purchase. Gate premium on the OR of your store entitlement and this:

final access = await InfluTo.instance.checkAccess(appUserId: 'user_123'); // appUserId optional
final isPremium = rcEntitlementActive || access.hasAccess;
// access also exposes: source, entitlement, expiresAt, code

Positive results are cached (in memory and persisted across cold starts, ~5-min TTL).

Automatic purchase capture (store-direct)

For store-direct apps (not RevenueCat), add the companion influto_iap package and the SDK reports purchases for you — no manual reportPurchase. It self-gates on store-direct, so RevenueCat apps stay silent.

# pubspec.yaml
dependencies:
  influto_iap: ^1.0.0   # companion; depends on in_app_purchase

final observer = InfluToPurchaseObserver(
  // Android one-time / consumable SKUs (omit if you only sell subscriptions; iOS needs none).
  oneTimeProductIds: {'coins_100', 'remove_ads'},
);
await observer.enable();   // listens to in_app_purchase + back-syncs existing purchases

Build & test

# Static gates + unit tests (run on Windows or WSL2):
dart analyze
dart format --set-exit-if-changed .
flutter test                       # the MockClient-backed contract tests

# Run the example on a device / AVD (Android builds on your Windows host):
cd example
flutter create --platforms=android .   # one-time: generate the android/ runner
flutter pub get
# Pass your API key at build/run time via --dart-define (never committed; the example
# defaults to a harmless "it_TEST_KEY" the backend rejects with 401). Get the key from
# the dashboard → your app → API key:
flutter run -d <android-device-id> --dart-define=INFLUTO_API_KEY=it_live_your_real_key

iOS builds require macOS + Xcode (Flutter-iOS can't be compiled on Windows/WSL2). The pure-Dart logic is fully unit-tested on any host with flutter test; only the on-device iOS smoke test (and reportPurchase with a real StoreKit2 JWS) needs a Mac.

Verify on the backend

After a sample run, GET /api/apps/{id}/events/recent:

• sdk_events[] shows each trackEvent once (dedup) with the right referral_code + platform;
• webhooks[] shows the purchase with "attributed": true + the matching referral_code.

Publish (pub.dev)

dart pub publish --dry-run    # check pub points / layout
dart pub publish              # or via GitHub Actions OIDC (no long-lived token)