diff --git a/src/c#/GeneralUpdate.Core/Configuration/AbstractBootstrap.cs b/src/c#/GeneralUpdate.Core/Configuration/AbstractBootstrap.cs
index 53b49b61..4e64cedc 100644
--- a/src/c#/GeneralUpdate.Core/Configuration/AbstractBootstrap.cs
+++ b/src/c#/GeneralUpdate.Core/Configuration/AbstractBootstrap.cs
@@ -1,4 +1,6 @@
+using System;
 using System.Collections.Concurrent;
+using System.Collections.Generic;
 using System.Diagnostics;
 using System.Threading.Tasks;
 using GeneralUpdate.Core.Strategy;
@@ -13,38 +15,42 @@ public abstract class AbstractBootstrap<TBootstrap, TStrategy>
     {
         private readonly ConcurrentDictionary<UpdateOption, UpdateOptionValue> _options;
 
-        protected internal AbstractBootstrap() => 
+        /// <summary>User-registered extension types for lazy instantiation.</summary>
+        private readonly Dictionary<Type, Type> _extensions = new();
+
+        protected internal AbstractBootstrap()
+        {
             _options = new ConcurrentDictionary<UpdateOption, UpdateOptionValue>();
+            PopulateDefaults();
+        }
 
         /// <summary>
-        /// Launch async udpate.
+        /// Populate all UpdateOptions with their best-practice defaults.
+        /// Subclasses can override to customize.
         /// </summary>
-        /// <returns></returns>
-        public abstract Task<TBootstrap> LaunchAsync();
+        protected virtual void PopulateDefaults()
+        {
+            Option(UpdateOptions.MaxConcurrency, 3);
+            Option(UpdateOptions.RetryCount, 3);
+            Option(UpdateOptions.EnableResume, true);
+            Option(UpdateOptions.VerifyChecksum, true);
+            Option(UpdateOptions.SilentAutoInstall, false);
+        }
 
+        public abstract Task<TBootstrap> LaunchAsync();
         protected abstract void ExecuteStrategy();
-        
         protected abstract Task ExecuteStrategyAsync();
-
         protected abstract TBootstrap StrategyFactory();
 
         /// <summary>
         /// Setting update configuration.
         /// </summary>
-        /// <typeparam name="T"></typeparam>
-        /// <param name="option">Configuration Action Enumeration.</param>
-        /// <param name="value">Value</param>
-        /// <returns></returns>
         public TBootstrap Option<T>(UpdateOption<T> option, T value)
         {
             if (value == null)
-            {
                 _options.TryRemove(option, out _);
-            }
             else
-            {
                 _options[option] = new UpdateOptionValue<T>(option, value);
-            }
             return (TBootstrap)this;
         }
 
@@ -62,5 +68,19 @@ public TBootstrap Option<T>(UpdateOption<T> option, T value)
                 return default;
             }
         }
+
+        // ═══════════ Extension point registration ═══════════
+
+        /// <summary>Register a custom update strategy.</summary>
+        public TBootstrap Strategy<T>() where T : IStrategy, new()
+        { _extensions[typeof(IStrategy)] = typeof(T); return (TBootstrap)this; }
+
+        /// <summary>Resolve a registered extension type, or null if not registered.</summary>
+        protected TExtension? ResolveExtension<TExtension>() where TExtension : class
+        {
+            if (_extensions.TryGetValue(typeof(TExtension), out var t))
+                return Activator.CreateInstance(t) as TExtension;
+            return null;
+        }
     }
-}
\ No newline at end of file
+}
diff --git a/src/c#/GeneralUpdate.Core/Configuration/UpdateOptions.cs b/src/c#/GeneralUpdate.Core/Configuration/UpdateOptions.cs
new file mode 100644
index 00000000..77b05d32
--- /dev/null
+++ b/src/c#/GeneralUpdate.Core/Configuration/UpdateOptions.cs
@@ -0,0 +1,49 @@
+using System;
+using System.Diagnostics;
+using System.Reflection;
+using System.Runtime.InteropServices;
+using System.Text;
+
+namespace GeneralUpdate.Core.Configuration
+{
+    /// <summary>
+    /// Convenience accessor for UpdateOption constants.
+    /// Maps to the underlying UpdateOption singleton constants.
+    /// New code should use UpdateOptions.X instead of UpdateOption.X.
+    /// </summary>
+    public static class UpdateOptions
+    {
+        // ═══ Core ═══
+        public static UpdateOption<int> AppType => UpdateOption.ValueOf<int>("APPTYPE");
+
+        // ═══ Existing options (backward-compatible) ═══
+        public static UpdateOption<Encoding> Encoding => UpdateOption.Encoding;
+        public static UpdateOption<string> Format => UpdateOption.Format;
+        public static UpdateOption<int?> DownloadTimeout => UpdateOption.DownloadTimeOut;
+        public static UpdateOption<bool?> DriveEnabled => UpdateOption.Drive;
+        public static UpdateOption<bool?> PatchEnabled => UpdateOption.Patch;
+        public static UpdateOption<bool?> BackupEnabled => UpdateOption.BackUp;
+        public static UpdateOption<UpdateMode?> Mode => UpdateOption.Mode;
+        public static UpdateOption<bool> Silent => UpdateOption.EnableSilentUpdate;
+
+        // ═══ New options ═══
+        public static readonly UpdateOption<string?> UpdateUrl = UpdateOption.ValueOf<string?>("UPDATEURL");
+        public static readonly UpdateOption<string> AppSecretKey = UpdateOption.ValueOf<string>("APPSECRETKEY");
+        public static readonly UpdateOption<string> AppName = UpdateOption.ValueOf<string>("APPNAME");
+        public static readonly UpdateOption<string> MainAppName = UpdateOption.ValueOf<string>("MAINAPPNAME");
+        public static readonly UpdateOption<string> InstallPath = UpdateOption.ValueOf<string>("INSTALLPATH");
+        public static readonly UpdateOption<string> ClientVersion = UpdateOption.ValueOf<string>("CLIENTVERSION");
+        public static readonly UpdateOption<string?> UpgradeClientVersion = UpdateOption.ValueOf<string?>("UPGRADECLIENTVERSION");
+        public static readonly UpdateOption<int?> Platform = UpdateOption.ValueOf<int?>("PLATFORM");
+        public static readonly UpdateOption<bool> SilentAutoInstall = UpdateOption.ValueOf<bool>("SILENTAUTOINSTALL");
+        public static readonly UpdateOption<int> MaxConcurrency = UpdateOption.ValueOf<int>("MAXCONCURRENCY");
+        public static readonly UpdateOption<bool> EnableResume = UpdateOption.ValueOf<bool>("ENABLERESUME");
+        public static readonly UpdateOption<int> RetryCount = UpdateOption.ValueOf<int>("RETRYCOUNT");
+        public static readonly UpdateOption<bool> VerifyChecksum = UpdateOption.ValueOf<bool>("VERIFYCHECKSUM");
+        public static readonly UpdateOption<string?> ReportUrl = UpdateOption.ValueOf<string?>("REPORTURL");
+        public static readonly UpdateOption<string?> ProductId = UpdateOption.ValueOf<string?>("PRODUCTID");
+        public static readonly UpdateOption<string?> PermissionScript = UpdateOption.ValueOf<string?>("PERMISSIONSCRIPT");
+        public static readonly UpdateOption<string?> Scheme = UpdateOption.ValueOf<string?>("SCHEME");
+        public static readonly UpdateOption<string?> Token = UpdateOption.ValueOf<string?>("TOKEN");
+    }
+}