Verisoul provides a Flutter SDK that allows you to implement fraud prevention in your cross-platform mobile applications. This guide covers the installation, configuration, and usage of the Verisoul Flutter SDK.

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Installation

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1. Add Dependency

Add the Verisoul SDK to your pubspec.yaml file:

dependencies:
   flutter:
      sdk: flutter
   #  ...
   
   verisoul_sdk: 0.1.0

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2. Update the Android minimum minSdk to 24 in android/app/build.gradle

 defaultConfig {
    minSdk = 24
    //...
}

If an exception occurs during the build stating that the ai.verisoul:android package cannot be downloaded, add the following Maven repository inside your android/build.gradle file:

allprojects {
    repositories {
    // ...

     maven { url = uri("https://us-central1-maven.pkg.dev/verisoul/android") }

    }
 }

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Usage

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1. Initialization

import 'package:verisoul_sdk/verisoul.dart';

void main() {
   WidgetsFlutterBinding.ensureInitialized();
   VerisoulSdk.configure(projectId: "Project ID ", environment: VerisoulEnvironment.prod);
   runApp(const MyApp());
}

When this is called Verisoul library will be initialized, initial data together with session ID will be gathered and uploaded to Verisoul backend.

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2. Get Session ID

Once the minimum amount of data is gathered the session ID becomes available. The session ID is needed in order to request a risk assessment from Verisoul’s API. Note that session IDs are short lived and will expire after 24 hours. The application can obtain session ID by providing the callback as shown below:

final session = await VerisoulSdk.getSessionApi();

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3. Provide Touch Events

GestureDetector(
  onPanDown: (event) {
    VerisoulSdk.touchEvent(
      x: event.localPosition.dx,
      y: event.localPosition.dy,
      action: MotionAction.down);
  },
  onPanEnd: (event) {
    VerisoulSdk.touchEvent(
      x: event.localPosition.dx,
      y: event.localPosition.dy,
      action: MotionAction.up);
  },
  onPanUpdate: (event){
    VerisoulSdk.touchEvent(
      x: event.localPosition.dx,
      y: event.localPosition.dy,
      action: MotionAction.move);
  },
  child: //... ),

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Android

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1. Provide Touch Events (Android only)

In order to gather touch events and compare them to device accelerometer sensor data, the app will need to provide touch events to Verisoul. you need to Edit th MainActivity, to override dispatchTouchEvent function and pass the data to Verisoul like shown below.

import ai.verisoul.sdk.Verisoul
import android.view.MotionEvent


class MainActivity: FlutterActivity(){
   override fun onTouchEvent(event: MotionEvent?): Boolean {
      Verisoul.onTouchEvent(event)
      return super.onTouchEvent(event)
   }
}

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iOS

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Capabilities

To fully utilize VerisoulSDK, you must add the App Attest capability to your project. This capability allows the SDK to perform necessary checks and validations to ensure the integrity and security of your application.

Update your app’s entitlements file:

<key>com.apple.developer.devicecheck.appattest-environment</key>
<string>production/development (depending on your needs)</string>

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Update the privacy manifest file

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN"
  "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<!--
   PrivacyInfo.xcprivacy
   test

   Created by Raine Scott on 1/30/25.
   Copyright (c) 2025 ___ORGANIZATIONNAME___.
   All rights reserved.
-->
<plist version="1.0">
  <dict>
    <!-- Privacy manifest file for Verisoul Fraud Prevention SDK for iOS -->
    <key>NSPrivacyTracking</key>
    <false/>

    <!-- Privacy manifest file for Verisoul Fraud Prevention SDK for iOS -->
    <key>NSPrivacyTrackingDomains</key>
    <array/>

    <!-- Privacy manifest file for Verisoul Fraud Prevention SDK for iOS -->
    <key>NSPrivacyCollectedDataTypes</key>
    <array>
      <dict>
        <!-- The value provided by Apple for 'Device ID' data type -->
        <key>NSPrivacyCollectedDataType</key>
        <string>NSPrivacyCollectedDataTypeDeviceID</string>

        <!-- Verisoul Fraud Prevention SDK does not link the 'Device ID' with user's identity -->
        <key>NSPrivacyCollectedDataTypeLinked</key>
        <false/>

        <!-- Verisoul Fraud Prevention SDK does not use 'Device ID' for tracking -->
        <key>NSPrivacyCollectedDataTypeTracking</key>
        <false/>

        <!-- Verisoul Fraud Prevention SDK uses 'Device ID' for App Functionality
             (prevent fraud and implement security measures) -->
        <key>NSPrivacyCollectedDataTypePurposes</key>
        <array>
          <string>NSPrivacyCollectedDataTypePurposeAppFunctionality</string>
        </array>
      </dict>
    </array>

    <!-- Privacy manifest file for Verisoul Fraud Prevention SDK for iOS -->
    <key>NSPrivacyAccessedAPITypes</key>
    <array>
      <dict>
        <!-- The value provided by Apple for 'System boot time APIs' -->
        <key>NSPrivacyAccessedAPIType</key>
        <string>NSPrivacyAccessedAPICategorySystemBootTime</string>

        <!-- Verisoul Fraud Prevention SDK uses 'System boot time APIs' to measure the amount of
             time that has elapsed between events that occurred within the SDK -->
        <key>NSPrivacyAccessedAPITypeReasons</key>
        <array>
          <string>35F9.1</string>
        </array>
      </dict>
    </array>
  </dict>
</plist>

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Next Steps