diff --git a/dotnet/src/Microsoft.Agents.AI.Hosting.OpenAI/IdGenerator.cs b/dotnet/src/Microsoft.Agents.AI.Hosting.OpenAI/IdGenerator.cs
index bd35fa8308..4798f1b79a 100644
--- a/dotnet/src/Microsoft.Agents.AI.Hosting.OpenAI/IdGenerator.cs
+++ b/dotnet/src/Microsoft.Agents.AI.Hosting.OpenAI/IdGenerator.cs
@@ -34,6 +34,7 @@ public IdGenerator(string? responseId, string? conversationId, int? randomSeed =
         this._random = randomSeed.HasValue ? new Random(randomSeed.Value) : null;
         this.ResponseId = responseId ?? NewId("resp", random: this._random);
         this.ConversationId = conversationId ?? NewId("conv", random: this._random);
+        this.IsNewConversation = conversationId is null;
         this._partitionId = GetPartitionIdOrDefault(this.ConversationId) ?? string.Empty;
     }
 
@@ -59,6 +60,11 @@ public static IdGenerator From(CreateResponse request)
     /// </summary>
     public string ConversationId { get; }
 
+    /// <summary>
+    /// Gets a value indicating whether this is a new conversation.
+    /// </summary>
+    public bool IsNewConversation { get; }
+
     /// <summary>
     /// Generates a new ID.
     /// </summary>
diff --git a/dotnet/src/Microsoft.Agents.AI.Hosting.OpenAI/Responses/AgentInvocationContext.cs b/dotnet/src/Microsoft.Agents.AI.Hosting.OpenAI/Responses/AgentInvocationContext.cs
index f21c2e84e9..5f716ea3f2 100644
--- a/dotnet/src/Microsoft.Agents.AI.Hosting.OpenAI/Responses/AgentInvocationContext.cs
+++ b/dotnet/src/Microsoft.Agents.AI.Hosting.OpenAI/Responses/AgentInvocationContext.cs
@@ -26,6 +26,11 @@ internal sealed class AgentInvocationContext(IdGenerator idGenerator, JsonSerial
     /// </summary>
     public string ConversationId => this.IdGenerator.ConversationId;
 
+    /// <summary>
+    /// Returns true, if conversation is new.
+    /// </summary>
+    public bool IsNewConversation => this.IdGenerator.IsNewConversation;
+
     /// <summary>
     /// Gets the JSON serializer options.
     /// </summary>
diff --git a/dotnet/src/Microsoft.Agents.AI.Hosting.OpenAI/Responses/HostedAgentResponseExecutor.cs b/dotnet/src/Microsoft.Agents.AI.Hosting.OpenAI/Responses/HostedAgentResponseExecutor.cs
index 01e7c60137..f520acb662 100644
--- a/dotnet/src/Microsoft.Agents.AI.Hosting.OpenAI/Responses/HostedAgentResponseExecutor.cs
+++ b/dotnet/src/Microsoft.Agents.AI.Hosting.OpenAI/Responses/HostedAgentResponseExecutor.cs
@@ -81,10 +81,13 @@ public async IAsyncEnumerable<StreamingResponseEvent> ExecuteAsync(
         [EnumeratorCancellation] CancellationToken cancellationToken = default)
     {
         string agentName = GetAgentName(request)!;
-        AIAgent agent = this._serviceProvider.GetRequiredKeyedService<AIAgent>(agentName);
+        string conversationId = context.ConversationId;
+
+        var agent = this._serviceProvider.GetRequiredKeyedService<AIAgent>(agentName);
+        var threadStore = this._serviceProvider.GetKeyedService<AgentThreadStore>(agent.Name);
+
         var chatOptions = new ChatOptions
         {
-            ConversationId = request.Conversation?.Id,
             Temperature = (float?)request.Temperature,
             TopP = (float?)request.TopP,
             MaxOutputTokens = request.MaxOutputTokens,
@@ -94,16 +97,25 @@ public async IAsyncEnumerable<StreamingResponseEvent> ExecuteAsync(
         var options = new ChatClientAgentRunOptions(chatOptions);
         var messages = new List<ChatMessage>();
 
+        AgentThread thread = !context.IsNewConversation && threadStore is not null
+            ? await threadStore.GetThreadAsync(agent, conversationId, cancellationToken).ConfigureAwait(false)
+            : agent.GetNewThread();
+
         foreach (var inputMessage in request.Input.GetInputMessages())
         {
             messages.Add(inputMessage.ToChatMessage());
         }
 
-        await foreach (var streamingEvent in agent.RunStreamingAsync(messages, options: options, cancellationToken: cancellationToken)
+        await foreach (var streamingEvent in agent.RunStreamingAsync(messages, thread, options: options, cancellationToken: cancellationToken)
             .ToStreamingResponseAsync(request, context, cancellationToken).ConfigureAwait(false))
         {
             yield return streamingEvent;
         }
+
+        if (threadStore is not null && thread is not null)
+        {
+            await threadStore.SaveThreadAsync(agent, conversationId, thread, cancellationToken).ConfigureAwait(false);
+        }
     }
 
     /// <summary>