📊 OpenTelemetry

using System.Diagnostics;
using System.Diagnostics.Metrics;
using Azure.AI.OpenAI;
using Azure.Identity;
using Microsoft.Agents.AI;
using Microsoft.Extensions.AI;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using OpenTelemetry;
using OpenTelemetry.Logs;
using OpenTelemetry.Metrics;
using OpenTelemetry.Resources;
using OpenTelemetry.Trace;

const string SourceName  = "MyAgentApp";
const string ServiceName = "AgentDemo";

var otlpEndpoint = Environment.GetEnvironmentVariable("OTEL_EXPORTER_OTLP_ENDPOINT")
                   ?? "http://localhost:4318";

// ── Tracing ────────────────────────────────────────────────────────
using var tracerProvider = Sdk.CreateTracerProviderBuilder()
    .SetResourceBuilder(ResourceBuilder.CreateDefault().AddService(ServiceName))
    .AddSource(SourceName)
    .AddHttpClientInstrumentation()
    .AddOtlpExporter(o => o.Endpoint = new Uri(otlpEndpoint))
    .Build();

// ── Metrics ────────────────────────────────────────────────────────
using var meterProvider = Sdk.CreateMeterProviderBuilder()
    .SetResourceBuilder(ResourceBuilder.CreateDefault().AddService(ServiceName))
    .AddMeter(SourceName)
    .AddHttpClientInstrumentation()
    .AddRuntimeInstrumentation()
    .AddOtlpExporter(o => o.Endpoint = new Uri(otlpEndpoint))
    .Build();

// ── Logging ────────────────────────────────────────────────────────
var services = new ServiceCollection();
services.AddLogging(b => b
    .SetMinimumLevel(LogLevel.Debug)
    .AddOpenTelemetry(o =>
    {
        o.SetResourceBuilder(ResourceBuilder.CreateDefault().AddService(ServiceName));
        o.AddOtlpExporter(x => x.Endpoint = new Uri(otlpEndpoint));
        o.IncludeFormattedMessage = true;
    }));

using var serviceProvider = services.BuildServiceProvider();
var loggerFactory = serviceProvider.GetRequiredService<ILoggerFactory>();
var logger = loggerFactory.CreateLogger<Program>();

// ── Custom instruments ─────────────────────────────────────────────
using var activitySource       = new ActivitySource(SourceName);
using var meter                = new Meter(SourceName);
var interactionCounter         = meter.CreateCounter<int>("agent.interactions");
var responseTimeHistogram      = meter.CreateHistogram<double>("agent.response_time_seconds");

// ── Agent setup ────────────────────────────────────────────────────
var endpoint   = Environment.GetEnvironmentVariable("AZURE_OPENAI_ENDPOINT")!;
var deployment = Environment.GetEnvironmentVariable("AZURE_OPENAI_DEPLOYMENT_NAME") ?? "gpt-4o-mini";

// Build an instrumented IChatClient pipeline, then wrap it in ChatClientAgent.
using var instrumentedClient = new AzureOpenAIClient(new Uri(endpoint), new DefaultAzureCredential())
    .GetChatClient(deployment)
    .AsIChatClient()
    .AsBuilder()
    .UseFunctionInvocation()
    .UseOpenTelemetry(sourceName: SourceName, configure: cfg => cfg.EnableSensitiveData = true)
    .Build();

// ChatClientAgent accepts a pre-built IChatClient and also supports the agent-level builder.
var agent = new ChatClientAgent(
        instrumentedClient,
        name: "DemoAgent",
        instructions: "You are a concise, helpful assistant.")
    .AsBuilder()
    .UseOpenTelemetry(sourceName: SourceName, configure: cfg => cfg.EnableSensitiveData = true)
    .Build();

var session = await agent.CreateSessionAsync();
logger.LogInformation("Agent session started");

// ── Interactive loop ───────────────────────────────────────────────
// Parent span wraps the entire conversation session.
using var sessionActivity = activitySource.StartActivity("Agent Session");
sessionActivity?.SetTag("agent.name", "DemoAgent");

while (true)
{
    Console.Write("You: ");
    var input = Console.ReadLine();
    if (string.IsNullOrWhiteSpace(input) || input == "exit") break;

    var sw = Stopwatch.StartNew();

    // Child span per interaction.
    using var interactionActivity = activitySource.StartActivity("Agent Interaction");
    interactionActivity?.SetTag("user.input", input);

    try
    {
        Console.Write("Agent: ");
        await foreach (var chunk in agent.RunStreamingAsync(input, session))
            Console.Write(chunk.Text);
        Console.WriteLine();

        sw.Stop();
        interactionCounter.Add(1, new KeyValuePair<string, object?>("status", "success"));
        responseTimeHistogram.Record(sw.Elapsed.TotalSeconds,
            new KeyValuePair<string, object?>("status", "success"));

        logger.LogInformation("Interaction completed in {Elapsed:F2}s", sw.Elapsed.TotalSeconds);
    }
    catch (Exception ex)
    {
        sw.Stop();
        interactionCounter.Add(1, new KeyValuePair<string, object?>("status", "error"));
        responseTimeHistogram.Record(sw.Elapsed.TotalSeconds,
            new KeyValuePair<string, object?>("status", "error"));
        interactionActivity?.SetStatus(ActivityStatusCode.Error, ex.Message);
        logger.LogError(ex, "Interaction failed: {Message}", ex.Message);
        Console.WriteLine($"Error: {ex.Message}");
    }
}

// dotnet add package Azure.Monitor.OpenTelemetry.Exporter

var appInsightsConnStr = Environment.GetEnvironmentVariable("APPLICATIONINSIGHTS_CONNECTION_STRING");

Sdk.CreateTracerProviderBuilder()
    // ... (existing configuration)
    .AddAzureMonitorTraceExporter(o => o.ConnectionString = appInsightsConnStr)
    .Build();