diff --git a/04-PracticalSamples/src/src/McpSample.AppHost/McpSample.AppHost.csproj b/04-PracticalSamples/src/src/McpSample.AppHost/McpSample.AppHost.csproj
index e235705..cfb8d68 100644
--- a/04-PracticalSamples/src/src/McpSample.AppHost/McpSample.AppHost.csproj
+++ b/04-PracticalSamples/src/src/McpSample.AppHost/McpSample.AppHost.csproj
@@ -14,7 +14,7 @@
 
 	<ItemGroup>
 		<PackageReference Include="Aspire.Hosting.AppHost" Version="9.4.2" />
-		<PackageReference Include="ModelContextProtocol" Version="0.3.0-preview.3" />
+		<PackageReference Include="ModelContextProtocol" Version="0.3.0-preview.4" />
 	</ItemGroup>
 
 	<ItemGroup>
diff --git a/04-PracticalSamples/src/src/McpSample.AspNetCoreServer/McpSample.AspNetCoreServer.csproj b/04-PracticalSamples/src/src/McpSample.AspNetCoreServer/McpSample.AspNetCoreServer.csproj
index 34de5b9..22eea14 100644
--- a/04-PracticalSamples/src/src/McpSample.AspNetCoreServer/McpSample.AspNetCoreServer.csproj
+++ b/04-PracticalSamples/src/src/McpSample.AspNetCoreServer/McpSample.AspNetCoreServer.csproj
@@ -8,8 +8,8 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="ModelContextProtocol" Version="0.3.0-preview.3" />
-    <PackageReference Include="ModelContextProtocol.Core" Version="0.3.0-preview.3" />
+    <PackageReference Include="ModelContextProtocol" Version="0.3.0-preview.4" />
+    <PackageReference Include="ModelContextProtocol.Core" Version="0.3.0-preview.4" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/04-PracticalSamples/src/src/McpSample.Chat/McpSample.BlazorChat.csproj b/04-PracticalSamples/src/src/McpSample.Chat/McpSample.BlazorChat.csproj
index 0663807..747a711 100644
--- a/04-PracticalSamples/src/src/McpSample.Chat/McpSample.BlazorChat.csproj
+++ b/04-PracticalSamples/src/src/McpSample.Chat/McpSample.BlazorChat.csproj
@@ -14,7 +14,7 @@
 		<PackageReference Include="Microsoft.Extensions.AI" Version="9.5.0" />
 		<PackageReference Include="Microsoft.Extensions.AI.AzureAIInference" Version="9.5.0-preview.1.25265.7" />
 		<PackageReference Include="Microsoft.Extensions.AI.Ollama" Version="9.5.0-preview.1.25265.7" />
-		<PackageReference Include="ModelContextProtocol" Version="0.3.0-preview.3" />
+		<PackageReference Include="ModelContextProtocol" Version="0.3.0-preview.4" />
 		<PackageReference Include="OpenAI" Version="2.2.0" />
 	</ItemGroup>
 
diff --git a/04-PracticalSamples/src/src/McpSample.ServiceDefaults/McpSample.ServiceDefaults.csproj b/04-PracticalSamples/src/src/McpSample.ServiceDefaults/McpSample.ServiceDefaults.csproj
index e4d4e0a..9920eeb 100644
--- a/04-PracticalSamples/src/src/McpSample.ServiceDefaults/McpSample.ServiceDefaults.csproj
+++ b/04-PracticalSamples/src/src/McpSample.ServiceDefaults/McpSample.ServiceDefaults.csproj
@@ -6,6 +6,7 @@
     <IsAspireSharedProject>true</IsAspireSharedProject>
   </PropertyGroup>
   <ItemGroup>
+    <PackageReference Include="ModelContextProtocol.Core" Version="0.3.0-preview.4" />
 	  <FrameworkReference Include="Microsoft.AspNetCore.App" />
 	  <PackageReference Include="Microsoft.Extensions.Http.Resilience" Version="9.8.0" />
 	  <PackageReference Include="Microsoft.Extensions.ServiceDiscovery" Version="9.3.1" />
@@ -14,6 +15,6 @@
 	  <PackageReference Include="OpenTelemetry.Instrumentation.AspNetCore" Version="1.12.0" />
 	  <PackageReference Include="OpenTelemetry.Instrumentation.Http" Version="1.12.0" />
 	  <PackageReference Include="OpenTelemetry.Instrumentation.Runtime" Version="1.12.0" />
-    <PackageReference Include="ModelContextProtocol" Version="0.3.0-preview.3" />
+    <PackageReference Include="ModelContextProtocol" Version="0.3.0-preview.4" />
   </ItemGroup>
 </Project>
\ No newline at end of file