From 3ea9c5fa5dbbb860995eead85acd40dd66f39914 Mon Sep 17 00:00:00 2001
From: Roger Barreto <19890735+rogerbarreto@users.noreply.github.com>
Date: Thu, 19 Feb 2026 10:40:27 +0000
Subject: [PATCH] .NET: Fixes AgentWithHostedMCP chat fails: ErrorHTTP 404 (:
 404) Resource not found (#3856)

* Update packages

* Fix run-request.http format
---
 .../AgentWithHostedMCP/AgentWithHostedMCP.csproj           | 7 +++----
 dotnet/samples/HostedAgents/AgentWithHostedMCP/Program.cs  | 2 +-
 .../HostedAgents/AgentWithHostedMCP/run-requests.http      | 2 ++
 3 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/dotnet/samples/HostedAgents/AgentWithHostedMCP/AgentWithHostedMCP.csproj b/dotnet/samples/HostedAgents/AgentWithHostedMCP/AgentWithHostedMCP.csproj
index b00e4a48de..361848c27d 100644
--- a/dotnet/samples/HostedAgents/AgentWithHostedMCP/AgentWithHostedMCP.csproj
+++ b/dotnet/samples/HostedAgents/AgentWithHostedMCP/AgentWithHostedMCP.csproj
@@ -35,11 +35,10 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Azure.AI.AgentServer.AgentFramework" Version="1.0.0-beta.5" />
-    <PackageReference Include="Azure.AI.OpenAI" Version="2.7.0-beta.2" />
+    <PackageReference Include="Azure.AI.AgentServer.AgentFramework" Version="1.0.0-beta.6" />
+    <PackageReference Include="Azure.AI.OpenAI" Version="2.8.0-beta.1" />
     <PackageReference Include="Azure.Identity" Version="1.17.1" />
-    <PackageReference Include="Microsoft.Agents.AI.OpenAI" Version="1.0.0-preview.251219.1" />
-    <PackageReference Include="Microsoft.Extensions.AI.OpenAI" Version="10.1.1-preview.1.25612.2" />
+    <PackageReference Include="Microsoft.Extensions.AI.OpenAI" Version="10.3.0" />
   </ItemGroup>
 
   <!-- Add analyzers with compatible versions -->
diff --git a/dotnet/samples/HostedAgents/AgentWithHostedMCP/Program.cs b/dotnet/samples/HostedAgents/AgentWithHostedMCP/Program.cs
index 827b161052..0898bc0252 100644
--- a/dotnet/samples/HostedAgents/AgentWithHostedMCP/Program.cs
+++ b/dotnet/samples/HostedAgents/AgentWithHostedMCP/Program.cs
@@ -9,7 +9,6 @@ using Azure.AI.OpenAI;
 using Azure.Identity;
 using Microsoft.Agents.AI;
 using Microsoft.Extensions.AI;
-using OpenAI.Responses;
 
 var endpoint = Environment.GetEnvironmentVariable("AZURE_OPENAI_ENDPOINT") ?? throw new InvalidOperationException("AZURE_OPENAI_ENDPOINT is not set.");
 var deploymentName = Environment.GetEnvironmentVariable("AZURE_OPENAI_DEPLOYMENT_NAME") ?? "gpt-4o-mini";
@@ -29,6 +28,7 @@ AIAgent agent = new AzureOpenAIClient(
     new Uri(endpoint),
     new DefaultAzureCredential())
     .GetResponsesClient(deploymentName)
+    .AsIChatClient()
     .CreateAIAgent(
         instructions: "You answer questions by searching the Microsoft Learn content only.",
         name: "MicrosoftLearnAgent",
diff --git a/dotnet/samples/HostedAgents/AgentWithHostedMCP/run-requests.http b/dotnet/samples/HostedAgents/AgentWithHostedMCP/run-requests.http
index cc26f43b90..b7c0b35efd 100644
--- a/dotnet/samples/HostedAgents/AgentWithHostedMCP/run-requests.http
+++ b/dotnet/samples/HostedAgents/AgentWithHostedMCP/run-requests.http
@@ -7,6 +7,7 @@ GET {{host}}/readiness
 ### Simple string input - Ask about MCP Tools
 POST {{endpoint}}
 Content-Type: application/json
+
 {
     "input": "Please summarize the Azure AI Agent documentation related to MCP Tool calling?"
 }
@@ -14,6 +15,7 @@ Content-Type: application/json
 ### Explicit input - Ask about Agent Framework
 POST {{endpoint}}
 Content-Type: application/json
+
 {
     "input": [
         {