chore: import upstream snapshot with attribution

dotnet/samples/02-agents/AGUI/Step04_HumanInLoop/Server/Program.cs

@@ -0,0 +1,77 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System.ComponentModel;
+using Azure.AI.OpenAI;
+using Azure.Identity;
+using Microsoft.Agents.AI;
+using Microsoft.Agents.AI.Hosting.AGUI.AspNetCore;
+using Microsoft.AspNetCore.Http.Json;
+using Microsoft.AspNetCore.HttpLogging;
+using Microsoft.Extensions.AI;
+using Microsoft.Extensions.Options;
+using OpenAI.Chat;
+using ServerFunctionApproval;
+
+WebApplicationBuilder builder = WebApplication.CreateBuilder(args);
+
+builder.Services.AddHttpLogging(logging =>
+{
+    logging.LoggingFields = HttpLoggingFields.RequestPropertiesAndHeaders | HttpLoggingFields.RequestBody
+        | HttpLoggingFields.ResponsePropertiesAndHeaders | HttpLoggingFields.ResponseBody;
+    logging.RequestBodyLogLimit = int.MaxValue;
+    logging.ResponseBodyLogLimit = int.MaxValue;
+});
+
+builder.Services.AddHttpClient().AddLogging();
+builder.Services.ConfigureHttpJsonOptions(options =>
+    options.SerializerOptions.TypeInfoResolverChain.Add(ApprovalJsonContext.Default));
+builder.Services.AddAGUIServer();
+
+// WARNING: When adding session persistence (e.g., WithInMemorySessionStore), or running in production,
+// make sure to also register a SessionIsolationKeyProvider to scope sessions by principal in multi-user
+// deployments, e.g.:
+// builder.Services.UseClaimsBasedSessionIsolation(new() { ClaimType = ClaimTypes.NameIdentifier });
+
+WebApplication app = builder.Build();
+
+app.UseHttpLogging();
+
+string endpoint = builder.Configuration["AZURE_OPENAI_ENDPOINT"]
+    ?? throw new InvalidOperationException("AZURE_OPENAI_ENDPOINT is not set.");
+string deploymentName = builder.Configuration["AZURE_OPENAI_DEPLOYMENT_NAME"]
+    ?? throw new InvalidOperationException("AZURE_OPENAI_DEPLOYMENT_NAME is not set.");
+
+// Define approval-required tool
+[Description("Approve the expense report.")]
+static string ApproveExpenseReport(string expenseReportId)
+{
+    return $"Expense report {expenseReportId} approved";
+}
+
+// Get JsonSerializerOptions
+var jsonOptions = app.Services.GetRequiredService<IOptions<JsonOptions>>().Value;
+
+// Create approval-required tool
+#pragma warning disable MEAI001 // Type is for evaluation purposes only
+AITool[] tools = [new ApprovalRequiredAIFunction(AIFunctionFactory.Create(ApproveExpenseReport))];
+#pragma warning restore MEAI001
+
+// Create base agent
+// WARNING: DefaultAzureCredential is convenient for development but requires careful consideration in production.
+// In production, consider using a specific credential (e.g., ManagedIdentityCredential) to avoid
+// latency issues, unintended credential probing, and potential security risks from fallback mechanisms.
+ChatClient openAIChatClient = new AzureOpenAIClient(
+        new Uri(endpoint),
+        new DefaultAzureCredential())
+    .GetChatClient(deploymentName);
+
+ChatClientAgent baseAgent = openAIChatClient.AsAIAgent(
+    name: "AGUIAssistant",
+    instructions: "You are a helpful assistant in charge of approving expenses",
+    tools: tools);
+
+// Wrap with ServerFunctionApprovalAgent
+var agent = new ServerFunctionApprovalAgent(baseAgent, jsonOptions.SerializerOptions);
+
+app.MapAGUIServer("/", agent);
+await app.RunAsync();