diff --git a/DurableMultiAgentTemplate.Client/Components/Chat/ChatThread.razor b/DurableMultiAgentTemplate.Client/Components/Chat/ChatThread.razor
index 48bb81a..90e5d7b 100644
--- a/DurableMultiAgentTemplate.Client/Components/Chat/ChatThread.razor
+++ b/DurableMultiAgentTemplate.Client/Components/Chat/ChatThread.razor
@@ -33,7 +33,7 @@
                                 @((MarkupString)Markdown.ToHtml(agentChatMessage.Message.Content))
                             </div>
                             <div>
-                                使用されたエージェント: @string.Join(", ", agentChatMessage.Message.CalledAgentNames)
+                                使用されたエージェント: @string.Join(", ", agentChatMessage.Message.CalledAgentNames ?? [])
                             </div>
                         </FluentGridItem>
                     </FluentGrid>
diff --git a/DurableMultiAgentTemplate.Client/Services/AgentChatService.cs b/DurableMultiAgentTemplate.Client/Services/AgentChatService.cs
index 4b7ef70..16e3920 100644
--- a/DurableMultiAgentTemplate.Client/Services/AgentChatService.cs
+++ b/DurableMultiAgentTemplate.Client/Services/AgentChatService.cs
@@ -26,7 +26,10 @@ public async Task<AgentResponseWithAdditionalInfoDto> GetAgentResponseAsync(Agen
         IProgress<AgentOrchestratorStatus>? progress = null,
         CancellationToken cancellationToken = default)
     {
-        var response = await httpClient.PostAsJsonAsync("api/invoke/async", agentRequestDto, cancellationToken);
+        var response = await httpClient.PostAsJsonAsync("api/invoke/async", 
+            agentRequestDto, 
+            _jsonSerializerOptions,
+            cancellationToken);
         response.EnsureSuccessStatusCode();
 
         var agentOrchestratorStatus = AgentOrchestratorStatus.NotStarted;
@@ -35,9 +38,11 @@ public async Task<AgentResponseWithAdditionalInfoDto> GetAgentResponseAsync(Agen
             throw new InvalidOperationException("The format of the response from the agent is invalid.");
 
         // The response from the agent is an async response, so we need to poll the status until it's completed.
+        var statusQueryGetUri = new Uri(invokeAsyncResult.StatusQueryGetUri).PathAndQuery;
+        statusQueryGetUri = statusQueryGetUri.TrimStart('/');
         while (cancellationToken.IsCancellationRequested == false)
         {
-            var statusResponse = await httpClient.GetAsync(invokeAsyncResult.StatusQueryGetUri, cancellationToken);
+            var statusResponse = await httpClient.GetAsync(statusQueryGetUri, cancellationToken);
             statusResponse.EnsureSuccessStatusCode();
             var status = await statusResponse.Content.ReadFromJsonAsync<OrchestrationStatus>(_jsonSerializerOptions, cancellationToken)
                 ?? throw new InvalidOperationException("The format of the status response from the agent is invalid.");
diff --git a/DurableMultiAgentTemplate.Client/appsettings.Development.json b/DurableMultiAgentTemplate.Client/appsettings.Development.json
index eac75cd..8f1a314 100644
--- a/DurableMultiAgentTemplate.Client/appsettings.Development.json
+++ b/DurableMultiAgentTemplate.Client/appsettings.Development.json
@@ -7,8 +7,11 @@
   },
   "Services": {
     "backend": {
+      "httpxxx": [
+        "http://localhost:7133/"
+      ],
       "http": [
-        "http://localhost:7133"
+        "https://cautious-carnival-g45p4rwr7fv7pg-7071.app.github.dev/"
       ]
     }
   },
diff --git a/DurableMultiAgentTemplate.Shared/Model/AgentOrchestratorStatus.cs b/DurableMultiAgentTemplate.Shared/Model/AgentOrchestratorStatus.cs
index 254a992..f995b6e 100644
--- a/DurableMultiAgentTemplate.Shared/Model/AgentOrchestratorStatus.cs
+++ b/DurableMultiAgentTemplate.Shared/Model/AgentOrchestratorStatus.cs
@@ -30,6 +30,7 @@ public AgentOrchestratorStatus(AgentOrchestratorStep step)
 /// <summary>
 /// Defines the steps of the agent orchestrator.
 /// </summary>
+[JsonConverter(typeof(JsonStringEnumConverter))]
 public enum AgentOrchestratorStep
 {
     /// <summary>
diff --git a/DurableMultiAgentTemplate.Shared/Model/IAdditionalInfo.cs b/DurableMultiAgentTemplate.Shared/Model/IAdditionalInfo.cs
index 6bee665..1fe78d9 100644
--- a/DurableMultiAgentTemplate.Shared/Model/IAdditionalInfo.cs
+++ b/DurableMultiAgentTemplate.Shared/Model/IAdditionalInfo.cs
@@ -6,6 +6,7 @@ namespace DurableMultiAgentTemplate.Shared.Model;
 /// Interface for additional information.
 /// Classes implementing this interface are used as supplementary information added to agent responses.
 /// </summary>
+[JsonPolymorphic(TypeDiscriminatorPropertyName = "type")]
 [JsonDerivedType(typeof(AdditionalMarkdownInfo), typeDiscriminator: "markdown")]
 [JsonDerivedType(typeof(AdditionalLinkInfo), typeDiscriminator: "link")]
 public interface IAdditionalInfo;
diff --git a/DurableMultiAgentTemplate.Test/Model/AdditionalInfoSerializationTest.cs b/DurableMultiAgentTemplate.Test/Model/AdditionalInfoSerializationTest.cs
new file mode 100644
index 0000000..b259f46
--- /dev/null
+++ b/DurableMultiAgentTemplate.Test/Model/AdditionalInfoSerializationTest.cs
@@ -0,0 +1,37 @@
+using System;
+using System.Text.Json;
+using DurableMultiAgentTemplate.Shared.Model;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using DurableMultiAgentTemplate.Model; // 追加
+
+namespace DurableMultiAgentTemplate.Test.Model;
+
+[TestClass]
+public class AdditionalInfoSerializationTest
+{
+    [TestMethod]
+    public void AdditionalMarkdownInfo_SerializeDeserialize_WorksCorrectly()
+    {
+        var original = new AdditionalMarkdownInfo("**bold text**");
+        IAdditionalInfo info = original;
+        var options = new JsonSerializerOptions { TypeInfoResolver = SourceGenerationContext.Default };
+        string json = JsonSerializer.Serialize(info, typeof(IAdditionalInfo), options);
+        var deserialized = (IAdditionalInfo)JsonSerializer.Deserialize(json, typeof(IAdditionalInfo), options)!;
+        Assert.IsInstanceOfType(deserialized, typeof(AdditionalMarkdownInfo));
+        Assert.AreEqual(original.MarkdownText, ((AdditionalMarkdownInfo)deserialized).MarkdownText);
+    }
+
+    [TestMethod]
+    public void AdditionalLinkInfo_SerializeDeserialize_WorksCorrectly()
+    {
+        var original = new AdditionalLinkInfo("Google", new Uri("https://www.google.com/"));
+        IAdditionalInfo info = original;
+        var options = new JsonSerializerOptions { TypeInfoResolver = SourceGenerationContext.Default };
+        string json = JsonSerializer.Serialize(info, typeof(IAdditionalInfo), options);
+        var deserialized = (IAdditionalInfo)JsonSerializer.Deserialize(json, typeof(IAdditionalInfo), options)!;
+        Assert.IsInstanceOfType(deserialized, typeof(AdditionalLinkInfo));
+        var link = (AdditionalLinkInfo)deserialized;
+        Assert.AreEqual(original.LinkText, link.LinkText);
+        Assert.AreEqual(original.Uri, link.Uri);
+    }
+}
diff --git a/DurableMultiAgentTemplate/Model/SourceGenerationContext.cs b/DurableMultiAgentTemplate/Model/SourceGenerationContext.cs
index 684cfa2..5202bcb 100644
--- a/DurableMultiAgentTemplate/Model/SourceGenerationContext.cs
+++ b/DurableMultiAgentTemplate/Model/SourceGenerationContext.cs
@@ -14,7 +14,7 @@ namespace DurableMultiAgentTemplate.Model;
 /// Configures the JSON serialization options and declares serializable types
 /// for performance optimization through source generation.
 /// </summary>
-[JsonSourceGenerationOptions(PropertyNamingPolicy = JsonKnownNamingPolicy.CamelCase, PropertyNameCaseInsensitive = true)]
+[JsonSourceGenerationOptions(PropertyNamingPolicy = JsonKnownNamingPolicy.CamelCase, PropertyNameCaseInsensitive = false)]
 [JsonSerializable(typeof(GetClimateRequest))]
 [JsonSerializable(typeof(GetDestinationSuggestRequest))]
 [JsonSerializable(typeof(GetHotelRequest))]
@@ -24,4 +24,4 @@ namespace DurableMultiAgentTemplate.Model;
 [JsonSerializable(typeof(AdditionalMarkdownInfo))]
 [JsonSerializable(typeof(AdditionalLinkInfo))]
 [JsonSerializable(typeof(AgentResponseWithAdditionalInfoFormat))]
-internal partial class SourceGenerationContext : JsonSerializerContext;
+public partial class SourceGenerationContext : JsonSerializerContext;