feat(appcheck): appcheck recaptcha enterprise support

packages/firebase_app_check/firebase_app_check/android/build.gradle

@@ -7,13 +7,15 @@ apply from: file("local-config.gradle")
 buildscript {
   ext.kotlin_version = "2.0.0"
   repositories {
+    mavenLocal()
     google()
     mavenCentral()
   }
 }
 
 rootProject.allprojects {
   repositories {
+    mavenLocal()
     google()
     mavenCentral()
   }
@@ -78,6 +80,7 @@ android {
     implementation platform("com.google.firebase:firebase-bom:${getRootProjectExtOrCoreProperty("FirebaseSDKVersion", firebaseCoreProject)}")
     implementation 'com.google.firebase:firebase-appcheck-debug'
     implementation 'com.google.firebase:firebase-appcheck-playintegrity'
+    implementation 'com.google.firebase:firebase-appcheck-recaptcha:16.0.0-beta01'
     implementation 'androidx.annotation:annotation:1.7.0'
   }
 }

packages/firebase_app_check/firebase_app_check/android/src/main/kotlin/io/flutter/plugins/firebase/appcheck/FirebaseAppCheckPlugin.kt

@@ -11,6 +11,7 @@ import com.google.firebase.FirebaseApp
 import com.google.firebase.appcheck.FirebaseAppCheck
 import com.google.firebase.appcheck.debug.DebugAppCheckProviderFactory
 import com.google.firebase.appcheck.playintegrity.PlayIntegrityAppCheckProviderFactory
+import com.google.firebase.appcheck.recaptcha.RecaptchaAppCheckProviderFactory
 import io.flutter.embedding.engine.plugins.FlutterPlugin
 import io.flutter.embedding.engine.plugins.FlutterPlugin.FlutterPluginBinding
 import io.flutter.plugin.common.BinaryMessenger
@@ -62,6 +63,11 @@ class FirebaseAppCheckPlugin : FlutterFirebasePlugin, FlutterPlugin, FirebaseApp
           firebaseAppCheck.installAppCheckProviderFactory(
               DebugAppCheckProviderFactory.getInstance())
         }
+        "recaptcha" -> {
+          firebaseAppCheck.installAppCheckProviderFactory(
+            RecaptchaAppCheckProviderFactory.getInstance()
+          )
+        }
         else -> {
           firebaseAppCheck.installAppCheckProviderFactory(
               PlayIntegrityAppCheckProviderFactory.getInstance())

packages/firebase_app_check/firebase_app_check/android/src/main/kotlin/io/flutter/plugins/firebase/appcheck/GeneratedAndroidFirebaseAppCheck.g.kt

@@ -1,7 +1,7 @@
 // Copyright 2025, the Chromium project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-// Autogenerated from Pigeon (v25.3.2), do not edit directly.
+// Autogenerated from Pigeon (v26.3.4), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 @file:Suppress("UNCHECKED_CAST", "ArrayInDataClass")
 
@@ -40,12 +40,11 @@ private object GeneratedAndroidFirebaseAppCheckPigeonUtils {
  * @property message The error message.
  * @property details The error details. Must be a datatype supported by the api codec.
  */
-class FlutterError(
-    val code: String,
-    override val message: String? = null,
-    val details: Any? = null
-) : Throwable()
-
+class FlutterError (
+  val code: String,
+  override val message: String? = null,
+  val details: Any? = null
+) : RuntimeException()
 private open class GeneratedAndroidFirebaseAppCheckPigeonCodec : StandardMessageCodec() {
   override fun readValueOfType(type: Byte, buffer: ByteBuffer): Any? {
     return super.readValueOfType(type, buffer)

packages/firebase_app_check/firebase_app_check/example/android/build.gradle

@@ -1,5 +1,6 @@
 allprojects {
     repositories {
+        mavenLocal()
         google()
         mavenCentral()
     }

packages/firebase_app_check/firebase_app_check/example/android/settings.gradle

@@ -22,7 +22,7 @@ plugins {
     // START: FlutterFire Configuration
     id "com.google.gms.google-services" version "4.3.15" apply false
     // END: FlutterFire Configuration
-    id "org.jetbrains.kotlin.android" version "1.9.22" apply false
+    id "org.jetbrains.kotlin.android" version "2.1.0" apply false
 }
 
 include ":app"

packages/firebase_app_check/firebase_app_check/example/lib/main.dart

@@ -79,13 +79,21 @@ class _FirebaseAppCheck extends State<FirebaseAppCheckExample> {
   final appCheck = FirebaseAppCheck.instance;
   String _message = '';
   String _eventToken = 'not yet';
+  late final TextEditingController _webSiteKeyController;
 
   @override
   void initState() {
+    _webSiteKeyController = TextEditingController(text: kWebRecaptchaSiteKey);
     appCheck.onTokenChange.listen(setEventToken);
     super.initState();
   }
 
+  @override
+  void dispose() {
+    _webSiteKeyController.dispose();
+    super.dispose();
+  }
+
   void setMessage(String message) {
     setState(() {
       _message = message;
@@ -101,16 +109,25 @@ class _FirebaseAppCheck extends State<FirebaseAppCheckExample> {
   Future<void> _activate({
     AndroidAppCheckProvider? android,
     AppleAppCheckProvider? apple,
+    String? webProviderType,
     WindowsAppCheckProvider? windows,
   }) async {
     try {
+      dynamic providerWeb;
+      if (webProviderType == 'enterprise') {
+        providerWeb = ReCaptchaEnterpriseProvider(_webSiteKeyController.text);
+      } else if (webProviderType == 'v3') {
+        providerWeb = ReCaptchaV3Provider(_webSiteKeyController.text);
+      }
+
       await appCheck.activate(
         providerAndroid: android ?? const AndroidPlayIntegrityProvider(),
         providerApple: apple ?? const AppleDeviceCheckProvider(),
-        providerWeb: ReCaptchaV3Provider(kWebRecaptchaSiteKey),
+        providerWeb: providerWeb,
         providerWindows: windows ?? const WindowsDebugProvider(),
       );
       final providerName = windows?.runtimeType.toString() ??
+          webProviderType ??
           apple?.runtimeType.toString() ??
           android?.runtimeType.toString() ??
           'default';
@@ -136,40 +153,103 @@ class _FirebaseAppCheck extends State<FirebaseAppCheckExample> {
               style: TextStyle(fontSize: 18, fontWeight: FontWeight.bold),
             ),
             const SizedBox(height: 8),
-            ElevatedButton(
-              onPressed: () => _activate(
-                android: const AndroidDebugProvider(),
-                apple: const AppleDebugProvider(),
-                windows: WindowsDebugProvider(
-                  debugToken:
-                      kWindowsDebugToken.isNotEmpty ? kWindowsDebugToken : null,
+            if (kIsWeb) ...[
+              ElevatedButton(
+                onPressed: () => _activate(
+                  webProviderType: 'v3',
                 ),
+                child: const Text('activate(Web reCAPTCHA v3)'),
               ),
-              child: const Text('activate(Debug)'),
-            ),
-            ElevatedButton(
-              onPressed: () => _activate(
-                android: const AndroidPlayIntegrityProvider(),
-                apple: const AppleDeviceCheckProvider(),
+              const SizedBox(height: 8),
+              TextField(
+                controller: _webSiteKeyController,
+                decoration: const InputDecoration(
+                  labelText: 'Web reCAPTCHA Site Key',
+                  border: OutlineInputBorder(),
+                ),
+              ),
+              const SizedBox(height: 8),
+              ElevatedButton(
+                onPressed: () => _activate(
+                  webProviderType: 'enterprise',
+                ),
+                child: const Text('activate(Web reCAPTCHA Enterprise)'),
+              ),
+            ],
+            if (!kIsWeb && defaultTargetPlatform == TargetPlatform.android) ...[
+              ElevatedButton(
+                onPressed: () => _activate(
+                  android: const AndroidDebugProvider(),
+                ),
+                child: const Text('activate(Android Debug)'),
+              ),
+              ElevatedButton(
+                onPressed: () => _activate(
+                  android: const AndroidPlayIntegrityProvider(),
+                ),
+                child: const Text('activate(Android Play Integrity)'),
+              ),
+
+              const SizedBox(height: 8),
+              ElevatedButton(
+                onPressed: () => _activate(
+                  android: const AndroidReCaptchaProvider(),
+                ),
+                child: const Text('activate(Android reCAPTCHA)'),
+              ),
+            ],
+            if (!kIsWeb &&
+                (defaultTargetPlatform == TargetPlatform.iOS ||
+                    defaultTargetPlatform == TargetPlatform.macOS)) ...[
+              ElevatedButton(
+                onPressed: () => _activate(
+                  apple: const AppleDebugProvider(),
+                ),
+                child: const Text('activate(Apple Debug)'),
+              ),
+              ElevatedButton(
+                onPressed: () => _activate(
+                  apple: const AppleDeviceCheckProvider(),
+                ),
+                child: const Text('activate(Apple DeviceCheck)'),
               ),
-              child: const Text('activate(PlayIntegrity / DeviceCheck)'),
-            ),
-            if (!kIsWeb)
               ElevatedButton(
                 onPressed: () => _activate(
                   apple: const AppleAppAttestProvider(),
                 ),
-                child: const Text('activate(AppAttest)'),
+                child: const Text('activate(Apple AppAttest)'),
               ),
-            if (!kIsWeb)
               ElevatedButton(
                 onPressed: () => _activate(
                   apple: const AppleAppAttestWithDeviceCheckFallbackProvider(),
                 ),
                 child: const Text(
-                  'activate(AppAttest + DeviceCheck fallback)',
+                  'activate(Apple AppAttest + DeviceCheck fallback)',
+                ),
+              ),
+              if (defaultTargetPlatform == TargetPlatform.iOS) ...[
+
+                const SizedBox(height: 8),
+                ElevatedButton(
+                  onPressed: () => _activate(
+                    apple: const AppleReCaptchaProvider(),
+                  ),
+                  child: const Text('activate(Apple reCAPTCHA)'),
+                ),
+              ],
+            ],
+            if (!kIsWeb && defaultTargetPlatform == TargetPlatform.windows) ...[
+              ElevatedButton(
+                onPressed: () => _activate(
+                  windows: WindowsDebugProvider(
+                    debugToken: kWindowsDebugToken.isNotEmpty
+                        ? kWindowsDebugToken
+                        : null,
+                  ),
                 ),
+                child: const Text('activate(Windows Debug)'),
               ),
+            ],
             const SizedBox(height: 16),
             const Text(
               'Actions',
@@ -226,15 +306,15 @@ class _FirebaseAppCheck extends State<FirebaseAppCheckExample> {
               child: const Text('Test Firestore with App Check'),
             ),
             const SizedBox(height: 20),
-            Text(
+            SelectableText(
               _message,
               style: const TextStyle(
                 color: Color.fromRGBO(47, 79, 79, 1),
                 fontSize: 16,
               ),
             ),
             const SizedBox(height: 20),
-            Text(
+            SelectableText(
               'Token from onTokenChange: $_eventToken',
               style: const TextStyle(
                 color: Color.fromRGBO(128, 0, 128, 1),