diff --git a/.gitignore b/.gitignore
index 8153c72..35ac2be 100644
--- a/.gitignore
+++ b/.gitignore
@@ -230,6 +230,8 @@ Thumbs.db
 .idea/
 
 # custom
+# Ignore environment-specific appsettings, but allow .example files
 /**/**/appsettings.*.json
+!/**/**/appsettings.*.json.example
 
 **/**/deployment.yml
diff --git a/src/Nocr.TelegramListener.Host/Infrastructure/HostBuilderFactory.cs b/src/Nocr.TelegramListener.Host/Infrastructure/HostBuilderFactory.cs
index 89b00e5..9773409 100644
--- a/src/Nocr.TelegramListener.Host/Infrastructure/HostBuilderFactory.cs
+++ b/src/Nocr.TelegramListener.Host/Infrastructure/HostBuilderFactory.cs
@@ -8,12 +8,24 @@ public class HostBuilderFactory<TStartup> where TStartup : class
     {
         var builder = Microsoft.Extensions.Hosting.Host.CreateDefaultBuilder(args)
             .ConfigureWebHostDefaults(host => { host.UseStartup<TStartup>(); })
-            .ConfigureAppConfiguration((_, configurationBuilder) =>
+            .ConfigureAppConfiguration((context, configurationBuilder) =>
             {
                 if (!string.IsNullOrWhiteSpace(baseDirectory))
                     configurationBuilder.SetBasePath(baseDirectory);
 
-                configurationBuilder.AddJsonFile("appsettings.protected.json", optional: true, reloadOnChange: true);
+                // Configuration priority (low to high):
+                // 1. appsettings.json (already loaded by CreateDefaultBuilder)
+                // 2. appsettings.{Environment}.json (already loaded)
+                // 3. User Secrets (already loaded in Development)
+                // 4. Environment Variables (already loaded) ← highest priority
+
+                // Debug mode: log configuration on startup
+                if (Environment.GetEnvironmentVariable("NOCR_DEBUG_MODE") == "true")
+                {
+                    Console.WriteLine("[NOCR_DEBUG] Configuration debug mode enabled");
+                    Console.WriteLine($"[NOCR_DEBUG] Environment: {context.HostingEnvironment.EnvironmentName}");
+                    Console.WriteLine($"[NOCR_DEBUG] Base Path: {baseDirectory ?? configurationBuilder.Build().GetValue<string>("ContentRoot") ?? "default"}");
+                }
             })
             .UseSerilog((ctx, logBuilder) =>
             {
diff --git a/src/Nocr.TelegramListener.Host/Infrastructure/Startup.cs b/src/Nocr.TelegramListener.Host/Infrastructure/Startup.cs
index 10f1c57..247ff0b 100644
--- a/src/Nocr.TelegramListener.Host/Infrastructure/Startup.cs
+++ b/src/Nocr.TelegramListener.Host/Infrastructure/Startup.cs
@@ -1,5 +1,6 @@
 using Microsoft.Extensions.Options;
 using Nocr.TelegramListener.AppServices;
+using Nocr.TelegramListener.AppServices.UpdateListeners;
 using Nocr.TelegramListener.Async.Api.Contracts.Events;
 using Nocr.TelegramListener.Core.Dates;
 using Nocr.TelegramListener.Core.Options;
@@ -22,6 +23,12 @@ public class Startup
 
     public void ConfigureServices(IServiceCollection services)
     {
+        // Debug mode: log loaded configuration
+        if (Environment.GetEnvironmentVariable("NOCR_DEBUG_MODE") == "true")
+        {
+            LogConfigurationDebug();
+        }
+
         services.AddSingleton<ICurrentDateProvider, DefaultCurrentDateProvider>();
         services.AddAppServices(Configuration);
 
@@ -41,6 +48,41 @@ public class Startup
                 .Routing(r => r.TypeBased()));
     }
 
+    private void LogConfigurationDebug()
+    {
+        Console.WriteLine("=== [NOCR_DEBUG] Configuration Values ===");
+
+        var rebusOptions = Configuration.GetSection(nameof(RebusRabbitMqOptions));
+        Console.WriteLine($"[NOCR_DEBUG] RebusRabbitMqOptions:");
+        Console.WriteLine($"[NOCR_DEBUG]   ConnectionString: {MaskConnectionString(rebusOptions["ConnectionString"])}");
+        Console.WriteLine($"[NOCR_DEBUG]   InputQueueName: {rebusOptions["InputQueueName"]}");
+        Console.WriteLine($"[NOCR_DEBUG]   DirectExchangeName: {rebusOptions["DirectExchangeName"]}");
+        Console.WriteLine($"[NOCR_DEBUG]   TopicsExchangeName: {rebusOptions["TopicsExchangeName"]}");
+
+        var wtOptions = Configuration.GetSection(nameof(WTelegramClientOptions));
+        Console.WriteLine($"[NOCR_DEBUG] WTelegramClientOptions:");
+        Console.WriteLine($"[NOCR_DEBUG]   ApiId: {wtOptions["ApiId"]}");
+        Console.WriteLine($"[NOCR_DEBUG]   ApiHash: {MaskSecret(wtOptions["ApiHash"])}");
+        Console.WriteLine($"[NOCR_DEBUG]   PhoneNumber: {MaskSecret(wtOptions["PhoneNumber"])}");
+
+        Console.WriteLine("=== [NOCR_DEBUG] End Configuration ===");
+    }
+
+    private static string MaskConnectionString(string? value)
+    {
+        if (string.IsNullOrEmpty(value)) return "(empty)";
+        // Mask password in connection string: amqp://user:pass@host -> amqp://user:***@host
+        var masked = System.Text.RegularExpressions.Regex.Replace(value, @"(?<=://)([^:]+):([^@]+)(?=@)", m => $"{m.Groups[1].Value}:***");
+        return masked;
+    }
+
+    private static string MaskSecret(string? value)
+    {
+        if (string.IsNullOrEmpty(value)) return "(empty)";
+        if (value.Length <= 4) return "***";
+        return $"{value.Substring(0, 2)}...{value.Substring(value.Length - 2)}";
+    }
+
     public void Configure(IApplicationBuilder app)
     {
         var bus = app.ApplicationServices.GetRequiredService<IBus>();
diff --git a/src/Nocr.TelegramListener.Host/appsettings.Development.json.example b/src/Nocr.TelegramListener.Host/appsettings.Development.json.example
new file mode 100644
index 0000000..7b0ec54
--- /dev/null
+++ b/src/Nocr.TelegramListener.Host/appsettings.Development.json.example
@@ -0,0 +1,17 @@
+{
+  // This file provides an example configuration for local VS Code debugging.
+  // Copy this file to appsettings.Development.json and fill in your actual values.
+  // Alternatively, use environment variables or User Secrets for sensitive data.
+
+  "RebusRabbitMqOptions": {
+    // RabbitMQ connection string for local development
+    // Format: amqp://username:password@hostname:port/
+    "ConnectionString": "amqp://admin:admin@localhost:5672/"
+  },
+  "WTelegramClientOptions": {
+    // Telegram API credentials - obtain from https://my.telegram.org/apps
+    "ApiId": "YOUR_API_ID",
+    "ApiHash": "YOUR_API_HASH",
+    "PhoneNumber": "YOUR_PHONE_NUMBER"
+  }
+}
diff --git a/src/Nocr.TelegramListener.Host/appsettings.DockerCompose.json.example b/src/Nocr.TelegramListener.Host/appsettings.DockerCompose.json.example
new file mode 100644
index 0000000..52527b6
--- /dev/null
+++ b/src/Nocr.TelegramListener.Host/appsettings.DockerCompose.json.example
@@ -0,0 +1,11 @@
+{
+  // This file provides an example configuration for Docker Compose deployment.
+  // Copy this file to appsettings.DockerCompose.json (or use environment variables).
+
+  "RebusRabbitMqOptions": {
+    // RabbitMQ connection string - use service name from docker-compose.yml
+    "ConnectionString": "amqp://admin:admin@nocr-rabbitmq:5672/"
+  }
+  // Note: WTelegramClientOptions should be provided via environment variables
+  // See docker-compose.yml or use .env file
+}