Program.cs

using Azure.AI.OpenAI;
using Azure.Identity;
using Microsoft.Agents.AI;
using Microsoft.Extensions.AI;
using Microsoft.Extensions.Configuration;

var config = new ConfigurationBuilder().AddUserSecrets<Program>().Build();
var endpoint = config["AzureOpenAI:Endpoint"] ?? throw new InvalidOperationException(
    "Missing 'AzureOpenAI:Endpoint'. Run: dotnet user-secrets set \"AzureOpenAI:Endpoint\" \"https://<your-resource>.openai.azure.com/\"");
var deploymentName = config["AzureOpenAI:Deployment"] ?? "gpt-5-mini";

IChatClient chatClient =
    new AzureOpenAIClient(
        new Uri(endpoint),
        new AzureCliCredential())
    .GetChatClient(deploymentName)
    .AsIChatClient();


AIAgent writer = chatClient.AsAIAgent(
    name: "Writer",
    instructions: "Write stories that are engaging and creative.");

AgentResponse response = await writer.RunAsync("Write a short story about a haunted house.");

Console.WriteLine(response.Text);