> This page is for Applications Protection. > For clean Markdown of any page, append .md to the page URL. > For a complete documentation index, see https://docs.humansecurity.com/llms.txt. # Flutter Integration ## Intro The SDK can be integrated into a [Flutter](https://flutter.dev/) project. If the app loads a HUMAN-protected site in `webview_flutter`, set `hybridAppPolicy.webRootDomains` and `hybridAppPolicy.supportExternalWebViews = true` in native start. There is no HUMAN Flutter package that turns that flag on for you. Automatic interceptor is not supported in Flutter. See [WebView container support](/applications/webview-container-support) for more information. ## How to start the SDK * The most important thing is to start the SDK as soon as possible in your app flow. The reason for that is when your app will send an URL request to your server before the SDK was started, the request will not include the SDK's HTTP headers. As a result, HUMAN's Enforcer could block the request and the SDK will not be able to present a challenge to the user. The best place to start the SDK is in the: * `Application`'s `onCreate` function on Android. * `AppDelegate`'s `didFinishLaunchingWithOptions` function on iOS. * You should start the SDK on the **main thread**. * Create a `HumanManager` object that will handle calls from Flutter side. * On Android, register the `HumanManager` in the `FlutterEngine`. * On iOS, setup the channel. Here is an example of how it should be: ### **Android** Kotlin / MainApplication.kt: ```kotlin import android.app.Application class MainApplication: Application() { override fun onCreate() { super.onCreate() HumanManager.start(this) } } ``` Kotlin / HumanManager.kt: ```kotlin import android.app.Application import com.humansecurity.mobile_sdk.HumanSecurity import com.humansecurity.mobile_sdk.main.policy.HSPolicy import com.humansecurity.mobile_sdk.main.policy.HSAutomaticInterceptorType import com.humansecurity.mobile_sdk.main.HSBotDefenderChallengeResult import io.flutter.plugin.common.MethodCall import io.flutter.plugin.common.MethodChannel import org.json.JSONObject class HumanManager { companion object { fun start(application: Application) { try { val policy = HSPolicy() policy.automaticInterceptorPolicy.interceptorType = HSAutomaticInterceptorType.NONE HumanSecurity.start(application, "", policy) } catch (exception: Exception) { println("Exception: ${exception.message}") } } fun handleEvent(call: MethodCall, result: MethodChannel.Result) { if (call.method == "humanGetHeaders") { val json = JSONObject((HumanSecurity.BD.headersForURLRequest("") as Map<*, *>?)) result.success(json.toString()) } else if (call.method == "humanHandleResponse") { val handled = HumanSecurity.BD.handleResponse(call.arguments!! as String) { challengeResult: HSBotDefenderChallengeResult -> result.success(if (challengeResult == HSBotDefenderChallengeResult.SOLVED) "solved" else "cancelled") null } if (!handled) { result.success("false") } } else { result.notImplemented() } } } } ``` Kotlin / MainActivity.kt: ```kotlin import androidx.annotation.NonNull import io.flutter.embedding.android.FlutterActivity import io.flutter.embedding.engine.FlutterEngine import io.flutter.plugin.common.MethodChannel class MainActivity: FlutterActivity() { override fun configureFlutterEngine(@NonNull flutterEngine: FlutterEngine) { super.configureFlutterEngine(flutterEngine) MethodChannel(flutterEngine.dartExecutor.binaryMessenger, "com.humansecurity/sdk").setMethodCallHandler { call, result -> HumanManager.handleEvent(call, result) } } } ``` ### **iOS** Swift / HumanManager.swift: ```swift import Foundation import Flutter import HUMAN class HumanManager { static let shared = HumanManager() func start() { do { let policy = HSPolicy() policy.automaticInterceptorPolicy.interceptorType = .none try HumanSecurity.start(appId: "", policy: policy) } catch { print("Error: \(error)") } } func setupChannel(with controller: FlutterViewController) { let humanChannel = FlutterMethodChannel(name: "com.humansecurity/sdk", binaryMessenger: controller.binaryMessenger) humanChannel.setMethodCallHandler({(call: FlutterMethodCall, result: @escaping FlutterResult) -> Void in if call.method == "humanGetHeaders" { var json: String? do { let headers = HumanSecurity.BD.headersForURLRequest(forAppId: "") let data = try JSONSerialization.data(withJSONObject: headers) json = String(data: data, encoding: .utf8) } catch { print("Error: \(error)") } result(json) } else if call.method == "humanHandleResponse" { if let response = call.arguments as? String, let data = response.data(using: .utf8), let httpURLResponse = HTTPURLResponse(url: URL(string: "https://example.com")!, statusCode: 403, httpVersion: nil, headerFields: nil) { let handled = HumanSecurity.BD.handleResponse(response: httpURLResponse, data: data) { challengeResult in result(challengeResult == .solved ? "solved" : "cancelled") } if handled { return } } result("false") } else { result("") } }) } } ``` Swift / AppDelegate.swift: ```swift import UIKit import Flutter @UIApplicationMain @objc class AppDelegate: FlutterAppDelegate { override func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool { GeneratedPluginRegistrant.register(with: self) HumanManager.shared.start() let controller : FlutterViewController = window?.rootViewController as! FlutterViewController HumanManager.shared.setupChannel(with: controller) return super.application(application, didFinishLaunchingWithOptions: launchOptions) } } ``` Let's talk about what we have in the code here: 1. We start the SDK as soon as possible and on the main thread. 2. We create a `HSPolicy` instance. This object is used to configure the SDK's behavior. Here, we set the `HSAutomaticInterceptorPolicy/interceptorType` property to `HSAutomaticInterceptorType/none`. This means that the *Automatic Interception* feature of the SDK is disabled. In short, this feature allows the SDK to manipulate URL requests and handle their responses by itself. However, this feature is not supported in Flutter. 3. We call the `HumanSecurity/start(appId:policy:)` function of the SDK. We provide the following parameters: * The `Application` instance (Android only). * Your AppID. * The policy object that we configured. Note: If your app communicates with several servers that have different AppID, you can call the `HumanSecurity/start(appIds:policy:)` function which allow you to pass an array of AppIDs. You should specify the relevant AppID for each API call in the SDK. ## How to add HTTP headers and handle block response In your Dart code, you should do the following: 1. Crate a `MethodChannel`. 2. Add The SDK's HTTP headers to your URL requests. 3. When a request is blocked, send the block response to the SDK. 4. Handle the challenge's result. Here is an example of how it should be: Dart: ```dart import 'package:flutter/material.dart'; import 'package:flutter/services.dart'; import '../settings/settings_view.dart'; import 'dart:async'; import 'dart:convert'; import 'package:http/http.dart' as http; class MyView extends StatelessWidget { static const humanPlatform = MethodChannel('com.humansecurity/sdk'); Future sendUrlRequest() async { try { final String humanHeaders = await humanPlatform.invokeMethod('humanGetHeaders'); final Map humanHeadersMap = Map.from(json.decode(humanHeaders)); var url = Uri.https('example.com', '/action'); var response = await http.get(url, headers: humanHeadersMap); if (response.statusCode == 403) { final String result = await humanPlatform.invokeMethod('humanHandleResponse', response.body); if (result == 'solved') { print("Challenge was solved"); } else if (result == 'false') { print("Request was not blocked by HUMAN"); } else if (result == 'cancelled') { print("Challenge was cancelled"); } } } on PlatformException catch (exception) { print("Exception: '${exception.message}'"); } } } ``` \ ## Understanding the block response 1. The HUMAN's Enforcer, when it decides to block a request, returns a JSON string in the response's body. The HTTP status code is 403. Here is an example of the response: ```json { "vid": "928d7ab3-9cf1-11ee-a624-b802520f369f", "uuid": "fd01e6d6-9cf2-11ee-808c-acde48001122", "page": "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"appId": "PXj9y4Q8Em", "action": "captcha", "collectorUrl": "https://collector-pxj9y4q8em.perimeterx.net" } ``` \ 2. The JSON contains metadata for the SDK. 3. Your app should pass the whole JSON to the SDK via the `HSBotDefender/handleResponse(response:data:callback:)` function. Otherwise, the SDK won't present a challenge to the user.