LinkForty Flutter SDK

Native Flutter SDK for deep linking, mobile attribution, and conversion tracking.

Features

• Deferred Deep Linking: Match app installs to link clicks using privacy-compliant fingerprinting
• Universal Links & App Links: Full support for iOS Universal Links and Android App Links (HTTPS deep links)
• Custom URL Schemes: Handle custom app URL schemes
• Event Tracking: Track in-app events and conversions
• Offline Support: Queue events when offline with automatic retry
• Privacy-First: No IDFA/GAID collection by default, complies with privacy requirements
• Programmatic Link Creation: Create short links directly from your app
• Pure Dart/Flutter: 100% Dart, standard Future/Stream APIs

Requirements

• Flutter 3.10+
• Dart 3.0+
• iOS 12.0+
• Android API 21+

Installation

Add the following to your pubspec.yaml file:

dependencies:
  forty_link: ^0.0.1

Or run:

flutter pub add forty_link

Quick Start

1. Initialize the SDK

Initialize the SDK in your main.dart or early in your app lifecycle.

import 'package:forty_link/link_forty.dart';
import 'package:forty_link/models/link_forty_config.dart';

void main() async {
  WidgetsFlutterBinding.ensureInitialized();

  // Initialize LinkForty
  try {
    final config = LinkFortyConfig(
      baseURL: Uri.parse('https://go.yourdomain.com'),
      apiKey: 'your-api-key', // Optional for self-hosted
      debug: true, // Enable debug logging
      attributionWindowHours: 168, // 7 days
    );
    
    final response = await LinkForty.initialize(config: config);
    print('LinkForty initialized. Install ID: ${response.installId}');
    
  } catch (e) {
    print('LinkForty initialization failed: $e');
  }

  runApp(const MyApp());
}

2. Handle Deferred Deep Links (Install Attribution)

Register a callback to handle deferred deep links. This is triggered when the app is installed from a link.

// checking attribution status
LinkForty.instance.onDeferredDeepLink((deepLinkData) {
  if (deepLinkData != null) {
    // User installed from a link - navigate to content
    print("Install attributed to: ${deepLinkData.shortCode}");
    print("UTM Source: ${deepLinkData.utmParameters?.source ?? "none"}");

    // Navigate to the right content
    final productId = deepLinkData.customParameters?['productId'];
    if (productId != null) {
      navigatorKey.currentState?.pushNamed('/product', arguments: productId);
    }
  } else {
    // Organic install - no attribution
    print("Organic install");
  }
});

3. Handle Direct Deep Links (Universal Links / App Links)

The SDK uses app_links internally to handle incoming links. You just need to register a callback.

// Handle deep links when app is running or opened from background
LinkForty.instance.onDeepLink((uri, deepLinkData) {
  print("Deep link opened: $uri");
  
  if (deepLinkData != null) {
    print("Link data: $deepLinkData");
    // Navigate using deep link path (e.g., /products/123)
    if (deepLinkData.deepLinkPath != null) {
       navigatorKey.currentState?.pushNamed(deepLinkData.deepLinkPath!);
    }
  }
});

Server-side resolution: When the SDK is initialized, deep links are automatically resolved via the server to provide enriched data including deepLinkPath, appScheme, and linkId. If the server is unreachable, the SDK falls back to local URL parsing.

4. Track Events

// Track a simple event
await LinkForty.instance.trackEvent('button_clicked');

// Track event with properties
await LinkForty.instance.trackEvent(
  'purchase',
  {
    'product_id': '123',
    'amount': 29.99,
    'currency': 'USD',
  },
);

// Track revenue
await LinkForty.instance.trackRevenue(
  amount: 29.99,
  currency: 'USD',
  properties: {'product_id': '123'},
);

5. Create Links Programmatically

import 'package:forty_link/models/create_link_options.dart';
import 'package:forty_link/models/utm_parameters.dart';

// ...

final result = await LinkForty.instance.createLink(
  CreateLinkOptions(
    deepLinkParameters: {'route': 'VIDEO_VIEWER', 'id': 'vid123'},
    title: 'Check this out!',
    utmParameters: UTMParameters(source: 'app', campaign: 'share'),
  ),
);

print("Share this link: ${result.url}");
// e.g., "https://go.yourdomain.com/tmpl/abc123"

Note: Requires an API key in LinkFortyConfig.

Platform Setup

Android

1. AndroidManifest.xml: Add the intent filters for App Links (HTTPS) and Custom Schemes.

<activity ...>
    <!-- App Links (Standard HTTPS) -->
    <intent-filter android:autoVerify="true">
        <action android:name="android.intent.action.VIEW" />
        <category android:name="android.intent.category.DEFAULT" />
        <category android:name="android.intent.category.BROWSABLE" />
        <data android:scheme="https" android:host="go.yourdomain.com" />
    </intent-filter>

    <!-- Custom Scheme (Optional) -->
    <intent-filter>
        <action android:name="android.intent.action.VIEW" />
        <category android:name="android.intent.category.DEFAULT" />
        <category android:name="android.intent.category.BROWSABLE" />
        <data android:scheme="yourapp" />
    </intent-filter>
</activity>

2. Asset Links: Ensure your .well-known/assetlinks.json is hosted on your domain.

iOS

1. Universal Links: Add the Associated Domains capability in Xcode.
   • applinks:go.yourdomain.com
2. Custom URL Schemes: Add your scheme in Info.plist under URL Types.
3. AASA File: Ensure your .well-known/apple-app-site-association is hosted on your domain.

Advanced Usage

Self-Hosted LinkForty Core

If you're running your own LinkForty Core instance:

final config = LinkFortyConfig(
  baseURL: Uri.parse('https://links.yourcompany.com'),
  apiKey: null, // No API key needed for self-hosted
  debug: false,
);
await LinkForty.initialize(config: config);

Retrieve Install Data

final installData = LinkForty.instance.getInstallData();
if (installData != null) {
  print("Short code: ${installData.shortCode}");
  print("UTM source: ${installData.utmParameters?.source ?? "none"}");
}

final installId = LinkForty.instance.getInstallId();
if (installId != null) {
  print("Install ID: $installId");
}

Event Queue Management

// Check queued events count
final count = LinkForty.instance.queuedEventCount;

// Manually flush event queue
await LinkForty.instance.flushEvents();

// Clear event queue
LinkForty.instance.clearEventQueue();

Clear Data (for testing)

await LinkForty.instance.clearData();

// Reset SDK to uninitialized state (only for testing)
LinkForty.instance.reset();

Privacy & Security

Privacy-First Design

• No Persistent IDs: Uses probabilistic fingerprinting only.
• Data Minimization: Collects only necessary attribution data.
• User Control: Provides clearData() for user data deletion.

Data Collected (for attribution only)

• Device timezone
• Device language
• Screen resolution
• OS version (Android/iOS)
• App version
• User-Agent string

HTTPS Required

The SDK enforces HTTPS for all API endpoints (except localhost, 127.0.0.1, and 10.0.2.2 for development).

Support

• Documentation: https://docs.linkforty.com
• Issues: GitHub Issues

License

LinkForty Flutter SDK is available under the MIT license. See LICENSE for more info.