Program.cs

// Copyright (c) Microsoft. All rights reserved.

#pragma warning disable IDE0002 // Simplify Member Access

using Azure;
using Azure.AI.OpenAI;
using Azure.Identity;
using Microsoft.Agents.AI;
using Microsoft.Agents.AI.Hosting.AzureFunctions;
using Microsoft.Azure.Functions.Worker.Builder;
using Microsoft.Extensions.Hosting;
using OpenAI.Chat;

// Get the Azure OpenAI endpoint and deployment name from environment variables.
string endpoint = Environment.GetEnvironmentVariable("AZURE_OPENAI_ENDPOINT")
    ?? throw new InvalidOperationException("AZURE_OPENAI_ENDPOINT is not set.");
string deploymentName = Environment.GetEnvironmentVariable("AZURE_OPENAI_DEPLOYMENT_NAME")
    ?? throw new InvalidOperationException("AZURE_OPENAI_DEPLOYMENT_NAME is not set.");

// Use Azure Key Credential if provided, otherwise use Azure CLI Credential.
string? azureOpenAiKey = System.Environment.GetEnvironmentVariable("AZURE_OPENAI_API_KEY");
// 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.
AzureOpenAIClient client = !string.IsNullOrEmpty(azureOpenAiKey)
    ? new AzureOpenAIClient(new Uri(endpoint), new AzureKeyCredential(azureOpenAiKey))
    : new AzureOpenAIClient(new Uri(endpoint), new DefaultAzureCredential());

// Single agent used by the orchestration to demonstrate sequential calls on the same session.
const string WriterName = "WriterAgent";
const string WriterInstructions =
    """
    You refine short pieces of text. When given an initial sentence you enhance it;
    when given an improved sentence you polish it further.
    """;

AIAgent writerAgent = client.GetChatClient(deploymentName).AsAIAgent(WriterInstructions, WriterName);

using IHost app = FunctionsApplication
    .CreateBuilder(args)
    .ConfigureFunctionsWebApplication()
    .ConfigureDurableAgents(options => options.AddAIAgent(writerAgent))
    .Build();

app.Run();