diff --git a/CS/console-ai-extension/Program.cs b/CS/console-ai-extension/Program.cs
index c1b0a39..a89cb97 100644
--- a/CS/console-ai-extension/Program.cs
+++ b/CS/console-ai-extension/Program.cs
@@ -34,17 +34,23 @@ static void Main(string[] args)
 
         public class SampleAITextModifier
         {
-            //Modify the following lines to obtain and pass your personal Azure OpenAI credentails to the Register* method.
-            string AzureOpenAIEndpoint { get { return Environment.GetEnvironmentVariable("AZURE_OPENAI_ENDPOINT"); } }
-            string AzureOpenAIKey { get { return Environment.GetEnvironmentVariable("AZURE_OPENAI_APIKEY"); } }
-            string DeploymentName { get { return Environment.GetEnvironmentVariable("AZURE_OPENAI_DEPLOYMENTNAME"); } }
-
             AIExtensionsContainerDefault defaultAIContainer;
 
             public SampleAITextModifier()
             {
-                IChatClient client = new AzureOpenAIClient(new Uri(AzureOpenAIEndpoint),
-                    new System.ClientModel.ApiKeyCredential(AzureOpenAIKey)).GetChatClient(DeploymentName).AsIChatClient();
+                //Modify the following lines to obtain and pass your personal Azure OpenAI credentails to the Register* method.
+                string azureOpenAIEndpoint = Environment.GetEnvironmentVariable("AZURE_OPENAI_ENDPOINT");
+                if (string.IsNullOrEmpty(azureOpenAIEndpoint))
+                    azureOpenAIEndpoint = "https://api.devexpress.com/demo-openai";//DevExpress demo proxy-server
+                string azureOpenAIKey = Environment.GetEnvironmentVariable("AZURE_OPENAI_APIKEY");
+                if (string.IsNullOrEmpty(azureOpenAIKey))
+                    azureOpenAIKey = "DEMO";//Demo key
+                string deploymentName = Environment.GetEnvironmentVariable("AZURE_OPENAI_DEPLOYMENTNAME");
+                if (string.IsNullOrEmpty(deploymentName))
+                    deploymentName = "demo";//DevExpress demo deployment
+
+                IChatClient client = new AzureOpenAIClient(new Uri(azureOpenAIEndpoint),
+                    new System.ClientModel.ApiKeyCredential(azureOpenAIKey)).GetChatClient(deploymentName).AsIChatClient();
                 defaultAIContainer = AIExtensionsContainerConsole.CreateDefaultAIExtensionContainer(client);
             }
 
diff --git a/CS/winforms-ai-extensions/Program.cs b/CS/winforms-ai-extensions/Program.cs
index 35e8149..141531b 100644
--- a/CS/winforms-ai-extensions/Program.cs
+++ b/CS/winforms-ai-extensions/Program.cs
@@ -6,11 +6,6 @@ namespace WinForms_AI_Extensions
 {
     internal static class Program
     {
-        //Modify the following lines to obtain and pass your personal Azure OpenAI credentails to the Register* method.
-        static string AzureOpenAIEndpoint { get { return Environment.GetEnvironmentVariable("AZURE_OPENAI_ENDPOINT"); } }
-        static string AzureOpenAIKey { get { return Environment.GetEnvironmentVariable("AZURE_OPENAI_APIKEY"); } }
-        static string DeploymentName { get { return Environment.GetEnvironmentVariable("AZURE_OPENAI_DEPLOYMENTNAME"); } }
-
         /// <summary>
         ///  The main entry point for the application.
         /// </summary>
@@ -32,8 +27,19 @@ private static void RegisterDevExpressAI()
             ///To register Ollama
             //OllamaChatClient ollamaChatClient = new OllamaChatClient("http://localhost:11434/", "llama3.1");
 
-            IChatClient azureOpenAIClient = new AzureOpenAIClient(new Uri(AzureOpenAIEndpoint),
-                   new System.ClientModel.ApiKeyCredential(AzureOpenAIKey)).GetChatClient(DeploymentName).AsIChatClient(); ;
+            //Modify the following lines to obtain and pass your personal Azure OpenAI credentails to the Register* method.
+            string azureOpenAIEndpoint = Environment.GetEnvironmentVariable("AZURE_OPENAI_ENDPOINT");
+            if (string.IsNullOrEmpty(azureOpenAIEndpoint))
+                azureOpenAIEndpoint = "https://api.devexpress.com/demo-openai";//DevExpress demo proxy-server
+            string azureOpenAIKey = Environment.GetEnvironmentVariable("AZURE_OPENAI_APIKEY");
+            if (string.IsNullOrEmpty(azureOpenAIKey))
+                azureOpenAIKey = "DEMO";//Demo key
+            string deploymentName = Environment.GetEnvironmentVariable("AZURE_OPENAI_DEPLOYMENTNAME");
+            if (string.IsNullOrEmpty(deploymentName))
+                deploymentName = "demo";//DevExpress demo deployment
+
+            IChatClient azureOpenAIClient = new AzureOpenAIClient(new Uri(azureOpenAIEndpoint),
+                   new System.ClientModel.ApiKeyCredential(azureOpenAIKey)).GetChatClient(deploymentName).AsIChatClient();
             AIExtensionsContainerDesktop.Default.RegisterChatClient(azureOpenAIClient);
         }
     }
diff --git a/CS/wpf-ai-extensions/App.xaml.cs b/CS/wpf-ai-extensions/App.xaml.cs
index 901559c..b0cb42d 100644
--- a/CS/wpf-ai-extensions/App.xaml.cs
+++ b/CS/wpf-ai-extensions/App.xaml.cs
@@ -16,11 +16,6 @@ namespace WPF_AI_Extensions
 
     public partial class App : System.Windows.Application
     {
-        //Modify the following lines to obtain and pass your personal Azure OpenAI credentails to the Register* method.
-        string AzureOpenAIEndpoint { get { return Environment.GetEnvironmentVariable("AZURE_OPENAI_ENDPOINT"); } }
-        string AzureOpenAIKey { get { return Environment.GetEnvironmentVariable("AZURE_OPENAI_APIKEY"); } }
-        string DeploymentName { get { return Environment.GetEnvironmentVariable("AZURE_OPENAI_DEPLOYMENTNAME"); } }
-
         protected override void OnStartup(StartupEventArgs e)
         {
             base.OnStartup(e);
@@ -31,8 +26,19 @@ protected override void OnStartup(StartupEventArgs e)
             ///To register Ollama
             //OllamaChatClient ollamaChatClient = new OllamaChatClient("http://localhost:11434/", "llama3.1");
 
-            IChatClient azureOpenAIClient = new AzureOpenAIClient(new Uri(AzureOpenAIEndpoint),
-                   new System.ClientModel.ApiKeyCredential(AzureOpenAIKey)).GetChatClient(DeploymentName).AsIChatClient();
+            //Modify the following lines to obtain and pass your personal Azure OpenAI credentails to the Register* method.
+            string azureOpenAIEndpoint = Environment.GetEnvironmentVariable("AZURE_OPENAI_ENDPOINT");
+            if (string.IsNullOrEmpty(azureOpenAIEndpoint))
+                azureOpenAIEndpoint = "https://api.devexpress.com/demo-openai";//DevExpress demo proxy-server
+            string azureOpenAIKey = Environment.GetEnvironmentVariable("AZURE_OPENAI_APIKEY");
+            if (string.IsNullOrEmpty(azureOpenAIKey))
+                azureOpenAIKey = "DEMO";//Demo key
+            string deploymentName = Environment.GetEnvironmentVariable("AZURE_OPENAI_DEPLOYMENTNAME");
+            if (string.IsNullOrEmpty(deploymentName))
+                deploymentName = "demo";//DevExpress demo deployment
+
+            IChatClient azureOpenAIClient = new AzureOpenAIClient(new Uri(azureOpenAIEndpoint),
+                   new System.ClientModel.ApiKeyCredential(azureOpenAIKey)).GetChatClient(deploymentName).AsIChatClient();
             AIExtensionsContainerDesktop.Default.RegisterChatClient(azureOpenAIClient);
         }
     }
diff --git a/README.md b/README.md
index b269fb4..8004c13 100644
--- a/README.md
+++ b/README.md
@@ -16,6 +16,8 @@ This example registers an Azure OpenAI service and uses AI APIs within a .NET 8
 
 >[!Note]
 > DevExpress does not provide a REST API or include built-in LLMs/SLMs. To use AI services, you need an active Azure/OpenAI subscription to obtain the necessary REST API endpoint, key, and model deployment name. This information must be added at application startup to register AI clients and enable DevExpress AI-powered features in your application.
+>
+> If these environment variables are not set, the sample falls back to the DevExpress demo proxy (`https://api.devexpress.com/demo-openai`) so you can try it out of the box. The demo proxy is rate-limited and intended for evaluation only — use your own Azure/OpenAI credentials for development.
 
 ## Implementation Details
 
@@ -40,16 +42,22 @@ Install the following NuGet packages:
 The following code in the `Program.cs` file registers an Azure AI service in the application:
 
 ```cs
-// Modify the following lines to obtain and pass your personal Azure OpenAI credentials to the `Register~` method.
-static string AzureOpenAIEndpoint { get { return Environment.GetEnvironmentVariable("AZURE_OPENAI_ENDPOINT"); } }
-static string AzureOpenAIKey { get { return Environment.GetEnvironmentVariable("AZURE_OPENAI_APIKEY"); } }
-static string DeploymentName { get { return Environment.GetEnvironmentVariable("AZURE_OPENAI_DEPLOYMENTNAME"); } }
-
 AIExtensionsContainerDefault defaultAIContainer;
 public SampleAITextModifier()
 {
-    IChatClient azureOpenAIClient = new AzureOpenAIClient(new Uri(AzureOpenAIEndpoint),
-            new System.ClientModel.ApiKeyCredential(AzureOpenAIKey)).GetChatClient(DeploymentName).AsIChatClient();
+    // Modify the following lines to obtain and pass your personal Azure OpenAI credentials to the `Register~` method.
+    string azureOpenAIEndpoint = Environment.GetEnvironmentVariable("AZURE_OPENAI_ENDPOINT");
+    if (string.IsNullOrEmpty(azureOpenAIEndpoint))
+        azureOpenAIEndpoint = "https://api.devexpress.com/demo-openai";//DevExpress demo proxy-server
+    string azureOpenAIKey = Environment.GetEnvironmentVariable("AZURE_OPENAI_APIKEY");
+    if (string.IsNullOrEmpty(azureOpenAIKey))
+        azureOpenAIKey = "DEMO";//Demo key
+    string deploymentName = Environment.GetEnvironmentVariable("AZURE_OPENAI_DEPLOYMENTNAME");
+    if (string.IsNullOrEmpty(deploymentName))
+        deploymentName = "demo";//DevExpress demo deployment
+
+    IChatClient azureOpenAIClient = new AzureOpenAIClient(new Uri(azureOpenAIEndpoint),
+            new System.ClientModel.ApiKeyCredential(azureOpenAIKey)).GetChatClient(deploymentName).AsIChatClient();
     AIExtensionsContainerDesktop.Default.RegisterChatClient(azureOpenAIClient);
 }
 ```
diff --git a/VB/console-ai-extension/Program.vb b/VB/console-ai-extension/Program.vb
index 40836d5..2f5906e 100644
--- a/VB/console-ai-extension/Program.vb
+++ b/VB/console-ai-extension/Program.vb
@@ -29,29 +29,18 @@ Namespace Runtime_AI_Extensions
 
         Public Class SampleAITextModifier
 
-            'Modify the following lines to obtain and pass your personal Azure OpenAI credentails to the Register* method.
-            Private ReadOnly Property AzureOpenAIEndpoint As String
-                Get
-                    Return Environment.GetEnvironmentVariable("AZURE_OPENAI_ENDPOINT")
-                End Get
-            End Property
-
-            Private ReadOnly Property AzureOpenAIKey As String
-                Get
-                    Return Environment.GetEnvironmentVariable("AZURE_OPENAI_APIKEY")
-                End Get
-            End Property
-
-            Private ReadOnly Property DeploymentName As String
-                Get
-                    Return Environment.GetEnvironmentVariable("AZURE_OPENAI_DEPLOYMENTNAME")
-                End Get
-            End Property
-
             Private defaultAIContainer As AIExtensionsContainerDefault
 
             Public Sub New()
-                Dim client As IChatClient = New AzureOpenAIClient(New Uri(AzureOpenAIEndpoint), New ClientModel.ApiKeyCredential(AzureOpenAIKey)).GetChatClient(DeploymentName).AsIChatClient()
+                'Modify the following lines to obtain and pass your personal Azure OpenAI credentails to the Register* method.
+                Dim azureOpenAIEndpoint As String = Environment.GetEnvironmentVariable("AZURE_OPENAI_ENDPOINT")
+                If String.IsNullOrEmpty(azureOpenAIEndpoint) Then azureOpenAIEndpoint = "https://api.devexpress.com/demo-openai" 'DevExpress demo proxy-server
+                Dim azureOpenAIKey As String = Environment.GetEnvironmentVariable("AZURE_OPENAI_APIKEY")
+                If String.IsNullOrEmpty(azureOpenAIKey) Then azureOpenAIKey = "DEMO" 'Demo key
+                Dim deploymentName As String = Environment.GetEnvironmentVariable("AZURE_OPENAI_DEPLOYMENTNAME")
+                If String.IsNullOrEmpty(deploymentName) Then deploymentName = "demo" 'DevExpress demo deployment
+
+                Dim client As IChatClient = New AzureOpenAIClient(New Uri(azureOpenAIEndpoint), New ClientModel.ApiKeyCredential(azureOpenAIKey)).GetChatClient(deploymentName).AsIChatClient()
                 defaultAIContainer = AIExtensionsContainerConsole.CreateDefaultAIExtensionContainer(client)
             End Sub
 
diff --git a/VB/winforms-ai-extensions/Program.vb b/VB/winforms-ai-extensions/Program.vb
index 43a7a8c..1a2be18 100644
--- a/VB/winforms-ai-extensions/Program.vb
+++ b/VB/winforms-ai-extensions/Program.vb
@@ -6,25 +6,6 @@ Namespace WinForms_AI_Extensions
 
     Friend Module Program
 
-        'Modify the following lines to obtain and pass your personal Azure OpenAI credentails to the Register* method.
-        Private ReadOnly Property AzureOpenAIEndpoint As String
-            Get
-                Return Environment.GetEnvironmentVariable("AZURE_OPENAI_ENDPOINT")
-            End Get
-        End Property
-
-        Private ReadOnly Property AzureOpenAIKey As String
-            Get
-                Return Environment.GetEnvironmentVariable("AZURE_OPENAI_APIKEY")
-            End Get
-        End Property
-
-        Private ReadOnly Property DeploymentName As String
-            Get
-                Return Environment.GetEnvironmentVariable("AZURE_OPENAI_DEPLOYMENTNAME")
-            End Get
-        End Property
-
         ''' <summary>
         '''  The main entry point for the application.
         ''' </summary>
@@ -41,7 +22,16 @@ Namespace WinForms_AI_Extensions
         Private Sub RegisterDevExpressAI()
             ''' To register Ollama
             'OllamaChatClient ollamaChatClient = new OllamaChatClient("http://localhost:11434/", "llama3.1");
-            Dim azureOpenAIClient As IChatClient = New AzureOpenAIClient(New Uri(AzureOpenAIEndpoint), New System.ClientModel.ApiKeyCredential(AzureOpenAIKey)).GetChatClient(DeploymentName).AsIChatClient()
+
+            'Modify the following lines to obtain and pass your personal Azure OpenAI credentails to the Register* method.
+            Dim azureOpenAIEndpoint As String = Environment.GetEnvironmentVariable("AZURE_OPENAI_ENDPOINT")
+            If String.IsNullOrEmpty(azureOpenAIEndpoint) Then azureOpenAIEndpoint = "https://api.devexpress.com/demo-openai" 'DevExpress demo proxy-server
+            Dim azureOpenAIKey As String = Environment.GetEnvironmentVariable("AZURE_OPENAI_APIKEY")
+            If String.IsNullOrEmpty(azureOpenAIKey) Then azureOpenAIKey = "DEMO" 'Demo key
+            Dim deploymentName As String = Environment.GetEnvironmentVariable("AZURE_OPENAI_DEPLOYMENTNAME")
+            If String.IsNullOrEmpty(deploymentName) Then deploymentName = "demo" 'DevExpress demo deployment
+
+            Dim azureOpenAIClient As IChatClient = New AzureOpenAIClient(New Uri(azureOpenAIEndpoint), New System.ClientModel.ApiKeyCredential(azureOpenAIKey)).GetChatClient(deploymentName).AsIChatClient()
             AIExtensionsContainerDesktop.Default.RegisterChatClient(azureOpenAIClient)
         End Sub
     End Module
diff --git a/VB/wpf-ai-extensions/App.xaml.vb b/VB/wpf-ai-extensions/App.xaml.vb
index 6289aa2..a460b0a 100644
--- a/VB/wpf-ai-extensions/App.xaml.vb
+++ b/VB/wpf-ai-extensions/App.xaml.vb
@@ -13,31 +13,21 @@ Namespace WPF_AI_Extensions
     Public Partial Class App
         Inherits System.Windows.Application
 
-        'Modify the following lines to obtain and pass your personal Azure OpenAI credentails to the Register* method.
-        Private ReadOnly Property AzureOpenAIEndpoint As String
-            Get
-                Return Environment.GetEnvironmentVariable("AZURE_OPENAI_ENDPOINT")
-            End Get
-        End Property
-
-        Private ReadOnly Property AzureOpenAIKey As String
-            Get
-                Return Environment.GetEnvironmentVariable("AZURE_OPENAI_APIKEY")
-            End Get
-        End Property
-
-        Private ReadOnly Property DeploymentName As String
-            Get
-                Return Environment.GetEnvironmentVariable("AZURE_OPENAI_DEPLOYMENTNAME")
-            End Get
-        End Property
-
         Protected Overrides Sub OnStartup(ByVal e As StartupEventArgs)
             MyBase.OnStartup(e)
             ApplicationThemeHelper.ApplicationThemeName = "Office2019Colorful"
             ''' To register Ollama
             'OllamaChatClient ollamaChatClient = new OllamaChatClient("http://localhost:11434/", "llama3.1");
-            Dim azureOpenAIClient As IChatClient = New AzureOpenAIClient(New Uri(AzureOpenAIEndpoint), New System.ClientModel.ApiKeyCredential(AzureOpenAIKey)).GetChatClient(DeploymentName).AsIChatClient()
+
+            'Modify the following lines to obtain and pass your personal Azure OpenAI credentails to the Register* method.
+            Dim azureOpenAIEndpoint As String = Environment.GetEnvironmentVariable("AZURE_OPENAI_ENDPOINT")
+            If String.IsNullOrEmpty(azureOpenAIEndpoint) Then azureOpenAIEndpoint = "https://api.devexpress.com/demo-openai" 'DevExpress demo proxy-server
+            Dim azureOpenAIKey As String = Environment.GetEnvironmentVariable("AZURE_OPENAI_APIKEY")
+            If String.IsNullOrEmpty(azureOpenAIKey) Then azureOpenAIKey = "DEMO" 'Demo key
+            Dim deploymentName As String = Environment.GetEnvironmentVariable("AZURE_OPENAI_DEPLOYMENTNAME")
+            If String.IsNullOrEmpty(deploymentName) Then deploymentName = "demo" 'DevExpress demo deployment
+
+            Dim azureOpenAIClient As IChatClient = New AzureOpenAIClient(New Uri(azureOpenAIEndpoint), New System.ClientModel.ApiKeyCredential(azureOpenAIKey)).GetChatClient(deploymentName).AsIChatClient()
             AIExtensionsContainerDesktop.Default.RegisterChatClient(azureOpenAIClient)
         End Sub
     End Class