diff --git a/global.json b/global.json
index 570baa6..cca5e9a 100644
--- a/global.json
+++ b/global.json
@@ -1,6 +1,6 @@
 {
   "sdk": {
-    "version": "10.0.102",
+    "version": "10.0.100",
     "rollForward": "latestPatch",
     "allowPrerelease": false
   }
diff --git a/src/PoVicTranslate.Web/Program.cs b/src/PoVicTranslate.Web/Program.cs
index 2e2ebcf..5cc9b55 100644
--- a/src/PoVicTranslate.Web/Program.cs
+++ b/src/PoVicTranslate.Web/Program.cs
@@ -116,20 +116,20 @@
 builder.Services.Configure<ApiSettings>(builder.Configuration.GetSection("ApiSettings"));
 
 // Register core services
-builder.Services.AddScoped<ITranslationService, TranslationService>();
-builder.Services.AddScoped<ILyricsService, LyricsService>();
+builder.Services.AddSingleton<ITranslationService, TranslationService>();
+builder.Services.AddSingleton<ILyricsService, LyricsService>();
 
 // Register validation services
 builder.Services.AddSingleton<ISpeechConfigValidator, SpeechConfigValidator>();
-builder.Services.AddScoped<IAudioSynthesisService, AudioSynthesisService>();
+builder.Services.AddSingleton<IAudioSynthesisService, AudioSynthesisService>();
 builder.Services.AddSingleton<IInputValidator, InputValidator>();
 
 // Register diagnostic validators
-builder.Services.AddScoped<IDiagnosticValidator, AzureOpenAIDiagnosticValidator>();
-builder.Services.AddScoped<IDiagnosticValidator, AzureSpeechDiagnosticValidator>();
-builder.Services.AddScoped<IDiagnosticValidator, InternetConnectivityDiagnosticValidator>();
-builder.Services.AddScoped<IConfigurationValidator, ConfigurationValidator>();
-builder.Services.AddScoped<IDiagnosticService, DiagnosticService>();
+builder.Services.AddSingleton<IDiagnosticValidator, AzureOpenAIDiagnosticValidator>();
+builder.Services.AddSingleton<IDiagnosticValidator, AzureSpeechDiagnosticValidator>();
+builder.Services.AddSingleton<IDiagnosticValidator, InternetConnectivityDiagnosticValidator>();
+builder.Services.AddSingleton<IConfigurationValidator, ConfigurationValidator>();
+builder.Services.AddSingleton<IDiagnosticService, DiagnosticService>();
 
 // Register utility services
 builder.Services.AddSingleton<ILyricsUtilityService, LyricsUtilityService>();
diff --git a/src/PoVicTranslate.Web/Services/TranslationService.cs b/src/PoVicTranslate.Web/Services/TranslationService.cs
index 8f7920e..e52a967 100644
--- a/src/PoVicTranslate.Web/Services/TranslationService.cs
+++ b/src/PoVicTranslate.Web/Services/TranslationService.cs
@@ -2,6 +2,7 @@
 using Azure.AI.OpenAI;
 using Microsoft.ApplicationInsights;
 using Microsoft.ApplicationInsights.DataContracts;
+using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Options;
 using OpenAI.Chat;
 using PoVicTranslate.Web.Configuration;
@@ -27,10 +28,20 @@ Maintain the sentiment and intent of the original text.
         Do not add any explanations, only provide the translated text.
         """;
 
+    [ActivatorUtilitiesConstructor]
     public TranslationService(
         IOptions<ApiSettings> apiSettings,
         TelemetryClient telemetryClient,
         ILogger<TranslationService> logger)
+        : this(apiSettings, telemetryClient, logger, null)
+    {
+    }
+
+    public TranslationService(
+        IOptions<ApiSettings> apiSettings,
+        TelemetryClient telemetryClient,
+        ILogger<TranslationService> logger,
+        ChatClient? chatClient)
     {
         ArgumentNullException.ThrowIfNull(apiSettings);
         _telemetryClient = telemetryClient;
@@ -39,6 +50,13 @@ public TranslationService(
         var settings = apiSettings.Value;
         _deploymentName = settings.AzureOpenAIDeploymentName;
 
+        if (chatClient is not null)
+        {
+            _chatClient = chatClient;
+            _logger.LogInformation("TranslationService initialized with injected ChatClient");
+            return;
+        }
+
         if (string.IsNullOrWhiteSpace(settings.AzureOpenAIApiKey) ||
             string.IsNullOrWhiteSpace(settings.AzureOpenAIEndpoint) ||
             string.IsNullOrWhiteSpace(settings.AzureOpenAIDeploymentName))