diff --git a/firebaseai/testapp/Assets/Firebase/Sample/FirebaseAI/UIHandler.cs b/firebaseai/testapp/Assets/Firebase/Sample/FirebaseAI/UIHandler.cs
index 69a0aa43..53dc3da5 100644
--- a/firebaseai/testapp/Assets/Firebase/Sample/FirebaseAI/UIHandler.cs
+++ b/firebaseai/testapp/Assets/Firebase/Sample/FirebaseAI/UIHandler.cs
@@ -14,6 +14,7 @@
 
 namespace Firebase.Sample.FirebaseAI {
   using Firebase;
+  using Firebase.AI;
   using Firebase.Extensions;
   using System;
   using System.Collections;
@@ -43,10 +44,6 @@ protected virtual void Start() {
       UIEnabled = true;
     }
 
-    void PlaceholderFunction() {
-      DebugLog("Placeholder Function called");
-    }
-
     protected void InitializeFirebase() {
       FirebaseApp.CheckAndFixDependenciesAsync().ContinueWithOnMainThread(task => {
         dependencyStatus = task.Result;
@@ -59,6 +56,47 @@ protected void InitializeFirebase() {
       });
     }
 
+    public string ModelName = "gemini-2.0-flash";
+
+    private int backendSelection = 0;
+    private string[] backendChoices = new string[] { "Google AI Backend", "Vertex AI Backend" };
+    private GenerativeModel GetModel() {
+      var backend = backendSelection == 0
+          ? FirebaseAI.Backend.GoogleAI()
+          : FirebaseAI.Backend.VertexAI();
+
+      return FirebaseAI.GetInstance(backend).GetGenerativeModel(ModelName);
+    }
+
+    // Send a single message to the Generative Model, without any history.
+    async Task SendSingleMessage(string message) {
+      DebugLog("Sending message to model: " + message);
+      var response = await GetModel().GenerateContentAsync(message);
+      DebugLog("Response: " + response.Text);
+    }
+
+    private Chat chatSession = null;
+    void StartChatSession() {
+      chatSession = GetModel().StartChat();
+    }
+
+    void CloseChatSession() {
+      chatSession = null;
+    }
+
+    // Send a message to the ongoing Chat with the Generative Model, which
+    // will preserve the history.
+    async Task SendChatMessage(string message) {
+      if (chatSession == null) {
+        DebugLog("Missing Chat Session");
+        return;
+      }
+
+      DebugLog("Sending chat message: " + message);
+      var response = await chatSession.SendMessageAsync(message);
+      DebugLog("Chat response: " + response.Text);
+    }
+
     // Exit if escape (or back, on mobile) is pressed.
     protected virtual void Update() {
       if (Input.GetKeyDown(KeyCode.Escape)) {
@@ -86,6 +124,8 @@ void GUIDisplayLog() {
       GUILayout.EndScrollView();
     }
 
+    private string textfieldString = "Hello";
+
     // Render the buttons and other controls.
     void GUIDisplayControls() {
       if (UIEnabled) {
@@ -93,8 +133,28 @@ void GUIDisplayControls() {
 
         GUILayout.BeginVertical();
 
-        if (GUILayout.Button("Placeholder Button")) {
-          PlaceholderFunction();
+        if (chatSession == null) {
+          backendSelection = GUILayout.SelectionGrid(backendSelection, backendChoices, backendChoices.Length);
+
+          textfieldString = GUILayout.TextField(textfieldString);
+
+          if (GUILayout.Button("Send Single Message")) {
+            _ = SendSingleMessage(textfieldString);
+          }
+
+          if (GUILayout.Button("Start Chat Session")) {
+            StartChatSession();
+          }
+        } else {
+          textfieldString = GUILayout.TextField(textfieldString);
+
+          if (GUILayout.Button("Send Chat Message")) {
+            _ = SendChatMessage(textfieldString);
+          }
+
+          if (GUILayout.Button("Close Chat Session")) {
+            CloseChatSession();
+          }
         }
 
         GUILayout.EndVertical();
diff --git a/firebaseai/testapp/Assets/Firebase/Sample/FirebaseAI/UIHandlerAutomated.cs b/firebaseai/testapp/Assets/Firebase/Sample/FirebaseAI/UIHandlerAutomated.cs
index 534b5a1b..b9fd553f 100644
--- a/firebaseai/testapp/Assets/Firebase/Sample/FirebaseAI/UIHandlerAutomated.cs
+++ b/firebaseai/testapp/Assets/Firebase/Sample/FirebaseAI/UIHandlerAutomated.cs
@@ -157,7 +157,7 @@ private bool ValidProbability(float value) {
     }
 
     // The model name to use for the tests.
-    private readonly string ModelName = "gemini-2.0-flash";
+    private readonly string TestModelName = "gemini-2.0-flash";
 
     private FirebaseAI GetFirebaseAI(Backend backend) {
       return backend switch {
@@ -170,7 +170,7 @@ private FirebaseAI GetFirebaseAI(Backend backend) {
 
     // Get a basic version of the GenerativeModel to test against.
     private GenerativeModel CreateGenerativeModel(Backend backend) {
-      return GetFirebaseAI(backend).GetGenerativeModel(ModelName);
+      return GetFirebaseAI(backend).GetGenerativeModel(TestModelName);
     }
 
     // Test if it can create the GenerativeModel.
@@ -273,7 +273,7 @@ async Task TestBasicImage(Backend backend) {
     async Task TestModelOptions(Backend backend) {
       // Note that most of these settings are hard to reliably verify, so as
       // long as the call works we are generally happy.
-      var model = GetFirebaseAI(backend).GetGenerativeModel(ModelName,
+      var model = GetFirebaseAI(backend).GetGenerativeModel(TestModelName,
         generationConfig: new GenerationConfig(
           temperature: 0.4f,
           topP: 0.4f,
@@ -315,7 +315,7 @@ async Task TestModelOptions(Backend backend) {
     async Task TestMultipleCandidates(Backend backend) {
       var genConfig = new GenerationConfig(candidateCount: 2);
 
-      var model = GetFirebaseAI(backend).GetGenerativeModel(ModelName,
+      var model = GetFirebaseAI(backend).GetGenerativeModel(TestModelName,
         generationConfig: genConfig
       );
 
@@ -387,7 +387,7 @@ private GenerativeModel CreateGenerativeModelWithBasicFunctionCall(
             }) }
         }));
 
-      return GetFirebaseAI(backend).GetGenerativeModel(ModelName,
+      return GetFirebaseAI(backend).GetGenerativeModel(TestModelName,
         tools: new Tool[] { tool },
         toolConfig: toolConfig
       );
@@ -439,7 +439,7 @@ async Task TestFunctionCallingNone(Backend backend) {
     // Test if setting a response schema with an enum works.
     async Task TestEnumSchemaResponse(Backend backend) {
       string enumValue = "MyTestEnum";
-      var model = GetFirebaseAI(backend).GetGenerativeModel(ModelName,
+      var model = GetFirebaseAI(backend).GetGenerativeModel(TestModelName,
         generationConfig: new GenerationConfig(
           responseMimeType: "text/x.enum",
           responseSchema: Schema.Enum(new string[] { enumValue })));
@@ -452,7 +452,7 @@ async Task TestEnumSchemaResponse(Backend backend) {
 
     // Test if setting a response schema with an enum works.
     async Task TestAnyOfSchemaResponse(Backend backend) {
-      var model = GetFirebaseAI(backend).GetGenerativeModel(ModelName,
+      var model = GetFirebaseAI(backend).GetGenerativeModel(TestModelName,
         generationConfig: new GenerationConfig(
           responseMimeType: "application/json",
           responseSchema: Schema.Array(
@@ -525,7 +525,7 @@ async Task TestChatFunctionCalling(Backend backend) {
         new Dictionary<string, Schema>() {
           { "input", Schema.String("Input string") },
         }));
-      var model = GetFirebaseAI(backend).GetGenerativeModel(ModelName,
+      var model = GetFirebaseAI(backend).GetGenerativeModel(TestModelName,
         tools: new Tool[] { tool }
       );
       var chat = model.StartChat();
@@ -619,7 +619,7 @@ async Task TestChatBasicTextStream(Backend backend) {
     // Test if calling CountTokensAsync works as expected.
     async Task TestCountTokens(Backend backend) {
       // Include some additional settings, since they are used in the call.
-      var model = GetFirebaseAI(backend).GetGenerativeModel(ModelName,
+      var model = GetFirebaseAI(backend).GetGenerativeModel(TestModelName,
         generationConfig: new GenerationConfig(temperature: 0.8f),
         systemInstruction: ModelContent.Text("This is a test SystemInstruction")
       );