diff --git a/Jugenddienst Stunden/Infrastructure/HttpClientRegistration.cs b/Jugenddienst Stunden/Infrastructure/HttpClientRegistration.cs
new file mode 100644
index 0000000..45a5adf
--- /dev/null
+++ b/Jugenddienst Stunden/Infrastructure/HttpClientRegistration.cs	
@@ -0,0 +1,29 @@
+using Jugenddienst_Stunden.Interfaces;
+using Microsoft.Extensions.DependencyInjection;
+using System.Net.Http;
+
+namespace Jugenddienst_Stunden.Infrastructure;
+
+internal static class HttpClientRegistration {
+	/// <summary>
+	/// Registriert den ApiClient mit einem SocketsHttpHandler als primären MessageHandler.
+	/// Vermeidet den Android-spezifischen Cast-Fehler in Xamarin.Android.Net.AndroidMessageHandler.
+	///</summary>
+	public static IServiceCollection AddApiHttpClient(this IServiceCollection services, ApiOptions options) {
+		if (services is null)
+			throw new ArgumentNullException(nameof(services));
+		if (options is null)
+			throw new ArgumentNullException(nameof(options));
+
+		// ApiOptions als Singleton bereitstellen (kann nach Bedarf angepasst werden)
+		services.AddSingleton(options);
+
+		// HttpClient für ApiClient registrieren und einen SocketsHttpHandler verwenden.
+		// SocketsHttpHandler vermeidet das problematische Casting, das bei AndroidMessageHandler
+		// zur InvalidCastException (URLConnectionInvoker -> HttpURLConnection) führt.
+		services.AddHttpClient<IApiClient, ApiClient>()
+			.ConfigurePrimaryHttpMessageHandler(() => new SocketsHttpHandler());
+
+		return services;
+	}
+}
diff --git a/Jugenddienst Stunden/Jugenddienst Stunden.csproj b/Jugenddienst Stunden/Jugenddienst Stunden.csproj
index d024a71..cb55cc9 100644
--- a/Jugenddienst Stunden/Jugenddienst Stunden.csproj	
+++ b/Jugenddienst Stunden/Jugenddienst Stunden.csproj	
@@ -263,6 +263,7 @@
         </PackageReference>
         <PackageReference Include="Microsoft.Maui.Controls.Compatibility" Version="9.0.110" />
         <PackageReference Include="Microsoft.Extensions.Logging.Debug" Version="9.0.9" />
+        <PackageReference Include="Microsoft.Extensions.Http" Version="9.0.0" />
         <PackageReference Include="Microsoft.Maui.Graphics" Version="9.0.110" />
         <PackageReference Include="Microsoft.NET.Runtime.MonoAOTCompiler.Task" Version="9.0.9" />
         <PackageReference Include="Microsoft.NET.Runtime.WebAssembly.Wasi.Sdk" Version="9.0.9" />
diff --git a/Jugenddienst Stunden/MauiProgram.cs b/Jugenddienst Stunden/MauiProgram.cs
index 560f694..1803843 100644
--- a/Jugenddienst Stunden/MauiProgram.cs	
+++ b/Jugenddienst Stunden/MauiProgram.cs	
@@ -9,6 +9,7 @@ using Microsoft.Extensions.Logging;
 using ZXing.Net.Maui.Controls;
 using System.Net.Http;
 using Jugenddienst_Stunden.ViewModels;
+using System.Net;
 
 namespace Jugenddienst_Stunden;
 
@@ -32,7 +33,7 @@ public static class MauiProgram {
 		//#if DEBUG
 		//		if (string.IsNullOrWhiteSpace(GlobalVar.ApiKey)) {
 		//			GlobalVar.ApiKey = Preferences.Default.Get("apiKey",
-		//				"MTQxfHNkdFptQkNZTXlPT3ZyMHNBZDl0UnVxNExMRXxodHRwOi8vaG91cnMuZGF1bmkubWluZS5udTo4MS9hcHBhcGk=");
+		//				"MTQxfHNkdFptQkNZTXlPT3ZyMHxodHRwOi8vaG91cnMuZGF1bmkubWluZS5udTo4MS9hcHBhcGk=");
 		//			GlobalVar.Name = Preferences.Default.Get("name", "Testserver: Isabell");
 		//			GlobalVar.Surname = Preferences.Default.Get("surname", "Biasi");
 		//			GlobalVar.EmployeeId = Preferences.Default.Get("EmployeeId", 141);
@@ -42,6 +43,10 @@ public static class MauiProgram {
 		//		builder.Logging.AddDebug();
 		//#endif
 
+		// ApiClient registrieren: SocketsHttpHandler als Primary Handler (vermeidet AndroidMessageHandler-Castfehler)
+		var apiOptions = new Infrastructure.ApiOptions { BaseUrl = GlobalVar.ApiUrl, Timeout = TimeSpan.FromSeconds(15) };
+		builder.Services.AddApiHttpClient(apiOptions);
+
 		// DI: AlertService für globale Alerts (z. B. leere ApiUrl)
 		builder.Services.AddSingleton<IAlertService, AlertService>();
 
@@ -50,17 +55,23 @@ public static class MauiProgram {
 
 		// DI: ApiOptions IMMER aus aktuellen Settings erzeugen (nicht beim Start einfrieren)
 		builder.Services.AddTransient(sp => new ApiOptions {
-			BaseUrl = sp.GetRequiredService<IAppSettings>().ApiUrl, Timeout = TimeSpan.FromSeconds(15)
+			BaseUrl = sp.GetRequiredService<IAppSettings>().ApiUrl,
+			Timeout = TimeSpan.FromSeconds(15)
 		});
 
 		// Token Provider soll ebenfalls aus Settings/Preferences lesen
 		builder.Services.AddSingleton<ITokenProvider, SettingsTokenProvider>();
 
 		// HttpClient + ApiClient
-		// Configure HttpClient with RequestLoggingHandler and disable automatic redirects for diagnosis
+		// Configure HttpClient with SocketsHttpHandler (managed) and RequestLoggingHandler
 		builder.Services.AddTransient<RequestLoggingHandler>();
 		builder.Services.AddSingleton<HttpClient>(sp => {
-			var nativeHandler = new HttpClientHandler { AllowAutoRedirect = false };
+			var nativeHandler = new SocketsHttpHandler {
+				AllowAutoRedirect = false,
+				AutomaticDecompression = DecompressionMethods.GZip | DecompressionMethods.Deflate,
+				PooledConnectionLifetime = TimeSpan.FromMinutes(5),
+				ConnectTimeout = TimeSpan.FromSeconds(10)
+			};
 			var logging = sp.GetRequiredService<RequestLoggingHandler>();
 			logging.InnerHandler = nativeHandler;
 			// HttpClient.Timeout will be adjusted by ApiClient if needed
@@ -95,16 +106,16 @@ public static class MauiProgram {
 		// DI: Validatoren
 		builder.Services.AddSingleton<IHoursValidator, HoursValidator>();
 
-  // DI: Services & Repositories
-  builder.Services.AddSingleton<IHoursRepository, HoursRepository>();
-  builder.Services.AddSingleton<IHoursService, HoursService>();
-  builder.Services.AddSingleton<IAuthService, AuthService>();
+		// DI: Services & Repositories
+		builder.Services.AddSingleton<IHoursRepository, HoursRepository>();
+		builder.Services.AddSingleton<IHoursService, HoursService>();
+		builder.Services.AddSingleton<IAuthService, AuthService>();
 
-  // DI: Views/ViewModels
-  builder.Services.AddTransient<ViewModels.StundenViewModel>();
-  builder.Services.AddTransient<Views.StundenPage>();
-  builder.Services.AddTransient<ViewModels.LoginViewModel>();
-  builder.Services.AddTransient<Views.LoginPage>();
+		// DI: Views/ViewModels
+		builder.Services.AddTransient<ViewModels.StundenViewModel>();
+		builder.Services.AddTransient<Views.StundenPage>();
+		builder.Services.AddTransient<ViewModels.LoginViewModel>();
+		builder.Services.AddTransient<Views.LoginPage>();
 
 		return builder.Build();
 	}