diff --git a/Serenity.sln b/Serenity.sln
index 8771d7d9e9..7b06931c97 100644
--- a/Serenity.sln
+++ b/Serenity.sln
@@ -85,6 +85,10 @@ Project("{54A90642-561A-4BB1-A94E-469ADEE60C69}") = "test-utils", "packages\test
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Serene.Web", "serene\src\Serene.Web\Serene.Web.csproj", "{0EE56BB8-D541-4152-8F50-10DE95B5DA1C}"
 EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "common-features-tests", "common-features-tests", "{BB7F4970-E88E-4963-BC28-E6B441BCC885}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Serenity.Extensions.Tests", "common-features\tests\Serenity.Extensions.Tests\Serenity.Extensions.Tests.csproj", "{91AC695B-AF0F-4226-97AD-4AC14C9C03C7}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -175,6 +179,10 @@ Global
 		{0EE56BB8-D541-4152-8F50-10DE95B5DA1C}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{0EE56BB8-D541-4152-8F50-10DE95B5DA1C}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{0EE56BB8-D541-4152-8F50-10DE95B5DA1C}.Release|Any CPU.Build.0 = Release|Any CPU
+		{91AC695B-AF0F-4226-97AD-4AC14C9C03C7}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{91AC695B-AF0F-4226-97AD-4AC14C9C03C7}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{91AC695B-AF0F-4226-97AD-4AC14C9C03C7}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{91AC695B-AF0F-4226-97AD-4AC14C9C03C7}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -204,6 +212,8 @@ Global
 		{9C4591C7-9BC1-497C-BB6F-FB74D739D5E9} = {4F13A746-0751-4EA0-BE46-A9A85886828F}
 		{769C42AD-B57D-45BE-AEA1-6490F09C26DD} = {E46C59F2-F5A2-441B-B858-6FDD7674EF5F}
 		{EE167232-372C-4036-AF27-AA3C586EC020} = {4F13A746-0751-4EA0-BE46-A9A85886828F}
+		{BB7F4970-E88E-4963-BC28-E6B441BCC885} = {CAD84B81-0B9D-4252-ADD0-5771F0B367AD}
+		{91AC695B-AF0F-4226-97AD-4AC14C9C03C7} = {BB7F4970-E88E-4963-BC28-E6B441BCC885}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {E2545865-7A32-47F4-A186-EDEBDCEF9EEF}
diff --git a/common-features/src/extensions/Modules/Options/ExtensionsTypeSource.cs b/common-features/src/extensions/Modules/Options/ExtensionsTypeSource.cs
new file mode 100644
index 0000000000..2f5dce4585
--- /dev/null
+++ b/common-features/src/extensions/Modules/Options/ExtensionsTypeSource.cs
@@ -0,0 +1,52 @@
+namespace Serenity.Extensions;
+
+/// <summary>
+/// Base type source for apps using Serenity.Extensions assembly and its reference chain
+/// </summary>
+/// <param name="assemblies">Additional assemblies to include</param>
+public class ExtensionsTypeSource(IEnumerable<Assembly> assemblies)
+    : DefaultTypeSource([..SerenityExtensionsAssemblyChain, ..assemblies])
+{
+    /// <summary>
+    /// Reference to Serenity.Net.Core assembly
+    /// </summary>
+    public static readonly Assembly SerenityNetCoreAssembly = typeof(Localization.ILocalText).Assembly;
+
+    /// <summary>
+    /// Reference to Serenity.Net.Data assembly
+    /// </summary>
+    public static readonly Assembly SerenityNetDataAssembly = typeof(DefaultSqlConnections).Assembly;
+
+    /// <summary>
+    /// Reference to Serenity.Net.Entity assembly
+    /// </summary>
+    public static readonly Assembly SerenityNetEntityAssembly = typeof(Row<>).Assembly;
+
+    /// <summary>
+    /// Reference to Serenity.Net.Services assembly
+    /// </summary>
+    public static readonly Assembly SerenityNetServicesAssembly = typeof(SaveRequestHandler<>).Assembly;
+
+    /// <summary>
+    /// Reference to Serenity.Net.Web assembly
+    /// </summary>
+    public static readonly Assembly SerenityNetWebAssembly = typeof(HttpContextItemsAccessor).Assembly;
+
+    /// <summary>
+    /// Reference to Serenity.Extensions assembly
+    /// </summary>
+    public static readonly Assembly SerenityExtensionsAssembly = typeof(ExtensionsTypeSource).Assembly;
+
+    /// <summary>
+    /// List of assemblies up to Serenity.Extensions
+    /// </summary>
+    public static readonly Assembly[] SerenityExtensionsAssemblyChain =
+    [
+        SerenityNetCoreAssembly,
+        SerenityNetDataAssembly,
+        SerenityNetEntityAssembly,
+        SerenityNetServicesAssembly,
+        SerenityNetWebAssembly,
+        SerenityExtensionsAssembly
+    ];
+}
\ No newline at end of file
diff --git a/common-features/tests/Directory.Build.props b/common-features/tests/Directory.Build.props
new file mode 100644
index 0000000000..d375c1ed88
--- /dev/null
+++ b/common-features/tests/Directory.Build.props
@@ -0,0 +1,6 @@
+<Project>
+  <Import Project="$(MSBuildThisFileDirectory)..\..\tests\Test.Build.props" />
+  <PropertyGroup>
+    <RootNamespace>Serenity.Tests</RootNamespace>
+  </PropertyGroup>
+</Project>
\ No newline at end of file
diff --git a/common-features/tests/Serenity.Extensions.Tests/ExtensionsTypeSourceTests.cs b/common-features/tests/Serenity.Extensions.Tests/ExtensionsTypeSourceTests.cs
new file mode 100644
index 0000000000..4546a82be8
--- /dev/null
+++ b/common-features/tests/Serenity.Extensions.Tests/ExtensionsTypeSourceTests.cs
@@ -0,0 +1,86 @@
+using Serenity.Extensions;
+
+namespace Serenity.Tests;
+
+public class ExtensionsTypeSourceTests
+{
+    [Fact]
+    public void IncludesExtensionsAssemblyChain()
+    {
+        var typeSource = new ExtensionsTypeSource([]);
+        var assemblies = typeSource.GetAssemblies()
+            .Select(x => x.GetName().Name);
+        Assert.Collection(assemblies,
+            x => Assert.Equal("Serenity.Net.Core", x),
+            x => Assert.Equal("Serenity.Net.Data", x),
+            x => Assert.Equal("Serenity.Net.Entity", x),
+            x => Assert.Equal("Serenity.Net.Services", x),
+            x => Assert.Equal("Serenity.Net.Web", x),
+            x => Assert.Equal("Serenity.Extensions", x));
+    }
+
+    [Fact]
+    public void IncludesPassedAssembliesAtEnd()
+    {
+        var typeSource = new ExtensionsTypeSource([typeof(ExtensionsTypeSourceTests).Assembly]);
+        var assemblies = typeSource.GetAssemblies()
+            .Select(x => x.GetName().Name);
+        Assert.Collection(assemblies,
+            x => Assert.Equal("Serenity.Net.Core", x),
+            x => Assert.Equal("Serenity.Net.Data", x),
+            x => Assert.Equal("Serenity.Net.Entity", x),
+            x => Assert.Equal("Serenity.Net.Services", x),
+            x => Assert.Equal("Serenity.Net.Web", x),
+            x => Assert.Equal("Serenity.Extensions", x),
+            x => Assert.Equal(typeof(ExtensionsTypeSourceTests).Assembly.GetName().Name, x));
+    }
+
+    [Fact]
+    public void ExtensionsAssemblyChainIsCorrect()
+    {
+        Assert.Collection(ExtensionsTypeSource.SerenityExtensionsAssemblyChain
+            .Select(x => x.GetName().Name),
+            x => Assert.Equal("Serenity.Net.Core", x),
+            x => Assert.Equal("Serenity.Net.Data", x),
+            x => Assert.Equal("Serenity.Net.Entity", x),
+            x => Assert.Equal("Serenity.Net.Services", x),
+            x => Assert.Equal("Serenity.Net.Web", x),
+            x => Assert.Equal("Serenity.Extensions", x));
+    }
+
+    [Fact]
+    public void CoreAssemblyIsCorrect()
+    {
+        Assert.Equal("Serenity.Net.Core", ExtensionsTypeSource.SerenityNetCoreAssembly.GetName().Name);
+    }
+
+    [Fact]
+    public void DataAssemblyIsCorrect()
+    {
+        Assert.Equal("Serenity.Net.Data", ExtensionsTypeSource.SerenityNetDataAssembly.GetName().Name);
+    }
+
+    [Fact]
+    public void EntityAssemblyIsCorrect()
+    {
+        Assert.Equal("Serenity.Net.Entity", ExtensionsTypeSource.SerenityNetEntityAssembly.GetName().Name);
+    }
+
+    [Fact]
+    public void ServicesAssemblyIsCorrect()
+    {
+        Assert.Equal("Serenity.Net.Services", ExtensionsTypeSource.SerenityNetServicesAssembly.GetName().Name);
+    }
+
+    [Fact]
+    public void WebAssemblyIsCorrect()
+    {
+        Assert.Equal("Serenity.Net.Web", ExtensionsTypeSource.SerenityNetWebAssembly.GetName().Name);
+    }
+
+    [Fact]
+    public void ExtensionsAssemblyIsCorrect()
+    {
+        Assert.Equal("Serenity.Extensions", ExtensionsTypeSource.SerenityExtensionsAssembly.GetName().Name);
+    }
+}
\ No newline at end of file
diff --git a/common-features/tests/Serenity.Extensions.Tests/Serenity.Extensions.Tests.csproj b/common-features/tests/Serenity.Extensions.Tests/Serenity.Extensions.Tests.csproj
new file mode 100644
index 0000000000..896c03fa5f
--- /dev/null
+++ b/common-features/tests/Serenity.Extensions.Tests/Serenity.Extensions.Tests.csproj
@@ -0,0 +1,6 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <ItemGroup>
+    <ProjectReference Include="..\..\src\extensions\Serenity.Extensions.csproj" />
+    <ProjectReference Include="..\..\..\tests\Serenity.Net.Web.Tests\Serenity.Net.Web.Tests.csproj" />
+  </ItemGroup>
+</Project>
\ No newline at end of file
diff --git a/serene/src/Serene.Web/Modules/Common/AppServices/TypeSource.cs b/serene/src/Serene.Web/Modules/Common/AppServices/TypeSource.cs
index 1fde7980b6..ebea12f322 100644
--- a/serene/src/Serene.Web/Modules/Common/AppServices/TypeSource.cs
+++ b/serene/src/Serene.Web/Modules/Common/AppServices/TypeSource.cs
@@ -1,29 +1,13 @@
 namespace Serene.AppServices;
 
-public class TypeSource : DefaultTypeSource
-{
-    public TypeSource()
-        : base(GetAssemblyList())
-    {
-    }
-
-    private static System.Reflection.Assembly[] GetAssemblyList()
-    {
-        return
-        [
-            typeof(Serenity.Localization.ILocalText).Assembly, // Serenity.Core
-            typeof(DefaultSqlConnections).Assembly, // Serenity.Net.Data
-            typeof(Row<>).Assembly, // Serenity.Net.Entity
-            typeof(SaveRequestHandler<>).Assembly, // Serenity.Net.Services
-            typeof(HttpContextItemsAccessor).Assembly, // Serenity.Net.Web
-            typeof(Serenity.Reporting.ExcelExporter).Assembly, // Serenity.Extensions
+public class TypeSource() : ExtensionsTypeSource([
 #if (Northwind)
-            typeof(Serenity.Demo.Northwind.CustomerPage).Assembly, // Serenity.Demo.Northwind
+    typeof(Serenity.Demo.Northwind.CustomerPage).Assembly, // Serenity.Demo.Northwind
 #endif
 #if (BasicSamples)
-            typeof(Serenity.Demo.BasicSamples.BasicSamplesPage).Assembly, // Serenity.Demo.BasicSamples
+    typeof(Serenity.Demo.BasicSamples.BasicSamplesPage).Assembly, // Serenity.Demo.BasicSamples
 #endif
-            typeof(Startup).Assembly // Serene.Web
-        ];
-    }
+    typeof(Startup).Assembly // Serene.Web
+])
+{
 }
\ No newline at end of file
diff --git a/serene/tests/Directory.Build.props b/serene/tests/Directory.Build.props
new file mode 100644
index 0000000000..39578d43c6
--- /dev/null
+++ b/serene/tests/Directory.Build.props
@@ -0,0 +1,6 @@
+<Project>
+  <Import Project="$(MSBuildThisFileDirectory)..\..\tests\Test.Build.props" />
+  <PropertyGroup>
+    <RootNamespace>Serene.Tests</RootNamespace>
+  </PropertyGroup>
+</Project>
\ No newline at end of file
diff --git a/serene/tests/Serene.Tests.Unit/AppServices/TypeSourceTests.cs b/serene/tests/Serene.Tests.Unit/AppServices/TypeSourceTests.cs
new file mode 100644
index 0000000000..dba70d4c95
--- /dev/null
+++ b/serene/tests/Serene.Tests.Unit/AppServices/TypeSourceTests.cs
@@ -0,0 +1,22 @@
+namespace Serene.Tests;
+
+public class TypeSourceTests
+{
+    [Fact]
+    public void IncludesCorrectAssemblyList()
+    {
+        var typeSource = new AppServices.TypeSource();
+        var assemblies = typeSource.GetAssemblies()
+            .Select(x => x.GetName().Name);
+        Assert.Collection(assemblies,
+            x => Assert.Equal("Serenity.Net.Core", x),
+            x => Assert.Equal("Serenity.Net.Data", x),
+            x => Assert.Equal("Serenity.Net.Entity", x),
+            x => Assert.Equal("Serenity.Net.Services", x),
+            x => Assert.Equal("Serenity.Net.Web", x),
+            x => Assert.Equal("Serenity.Extensions", x),
+            x => Assert.Equal("Serenity.Demo.Northwind", x),
+            x => Assert.Equal("Serenity.Demo.BasicSamples", x),
+            x => Assert.Equal("Serene.Web", x));
+    }
+}
\ No newline at end of file
diff --git a/serene/tests/Serene.Tests.Unit/Serene.Tests.Unit.csproj b/serene/tests/Serene.Tests.Unit/Serene.Tests.Unit.csproj
new file mode 100644
index 0000000000..b2e8853ce6
--- /dev/null
+++ b/serene/tests/Serene.Tests.Unit/Serene.Tests.Unit.csproj
@@ -0,0 +1,6 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <ItemGroup>
+    <ProjectReference Include="..\..\src\Serene.Web\Serene.Web.csproj" />
+    <ProjectReference Include="..\..\..\common-features\tests\Serenity.Extensions.Tests\Serenity.Extensions.Tests.csproj" />
+  </ItemGroup>
+</Project>
\ No newline at end of file
diff --git a/tests/GlobalUsings.cs b/tests/GlobalUsings.cs
deleted file mode 100644
index 5f282702bb..0000000000
--- a/tests/GlobalUsings.cs
+++ /dev/null
@@ -1 +0,0 @@
-
\ No newline at end of file