Microsoft Agent Framework for C#

Microsoft Agent Framework is Microsoft’s open-source SDK for building AI agents. Its C# SDK emits OpenTelemetry spans using GenAI semantic conventions. Arize AX ingests these spans directly and displays agent, model, and tool activity without an OpenInference processor.

Prerequisites

.NET 10 SDK
An Arize AX account (sign up)
An OPENAI_API_KEY from the OpenAI Platform

Launch Arize AX

Sign in to your Arize AX account.
From Space Settings, copy your Space ID and API Key. You will set them as ARIZE_SPACE_ID and ARIZE_API_KEY below.

Install

Create a console project and add the Microsoft Agent Framework OpenAI connector and the OpenTelemetry Protocol exporter:

dotnet new console --framework net10.0 --name MicrosoftAgentFramework
cd MicrosoftAgentFramework
dotnet add package Microsoft.Agents.AI.OpenAI --version 1.24.0
dotnet add package OpenTelemetry.Exporter.OpenTelemetryProtocol --version 1.19.1

Configure credentials

export ARIZE_SPACE_ID="<your-space-id>"
export ARIZE_API_KEY="<your-api-key>"
export ARIZE_PROJECT_NAME="microsoft-agent-framework-csharp-example"
export OPENAI_API_KEY="<your-openai-api-key>"

Setup tracing

The example configures an OTLP gRPC exporter for Arize AX, adds the project name as a resource attribute, and instruments one agent with a GetWeather function tool. GPT-6.1 Sol requires the Responses API for tool calling, so the agent uses GetResponsesClient() (OpenAI model documentation).

EnableSensitiveData = true records prompts, responses, tool arguments, and tool results. Use it only when that data is appropriate for your Arize AX project and its retention policy. Set it to false to omit message content.

#pragma warning disable OPENAI001

using System.ComponentModel;
using Microsoft.Agents.AI;
using Microsoft.Extensions.AI;
using OpenAI;
using OpenAI.Responses;
using OpenTelemetry;
using OpenTelemetry.Resources;
using OpenTelemetry.Trace;

const string sourceName = "Microsoft.AgentFramework.Sample";
var apiKey = Environment.GetEnvironmentVariable("ARIZE_API_KEY")!;
var spaceId = Environment.GetEnvironmentVariable("ARIZE_SPACE_ID")!;
var projectName = Environment.GetEnvironmentVariable("ARIZE_PROJECT_NAME")
    ?? "microsoft-agent-framework-csharp-example";
var openAiKey = Environment.GetEnvironmentVariable("OPENAI_API_KEY")!;

using var tracerProvider = Sdk.CreateTracerProviderBuilder()
    .SetResourceBuilder(ResourceBuilder.CreateDefault()
        .AddService("microsoft-agent-framework-csharp")
        .AddAttributes(new Dictionary<string, object>
        {
            ["openinference.project.name"] = projectName
        }))
    .AddSource(sourceName)
    .AddOtlpExporter(options =>
    {
        options.Endpoint = new Uri("https://otlp.arize.com:443");
        options.Protocol = OpenTelemetry.Exporter.OtlpExportProtocol.Grpc;
        options.Headers = $"authorization={apiKey},"+
                          $"arize-space-id={spaceId}," +
                          "arize-interface=dotnet";
    })
    .Build();

Console.WriteLine("Arize AX tracing initialized.");

var openAiClient = new OpenAIClient(openAiKey);

var agent = openAiClient.GetResponsesClient().AsAIAgent(
        model: "gpt-6.1-sol",
        name: "weather-agent",
        instructions:
            "You are a concise weather assistant. Always call the GetWeather " +
            "tool once before answering.",
        tools: [AIFunctionFactory.Create(WeatherTools.GetWeather)])
    .AsBuilder()
    .UseOpenTelemetry(
        sourceName, telemetry => telemetry.EnableSensitiveData = true)
    .Build();

The agent instrumentation emits the agent invocation, chat client, and function execution spans. The tracer provider listens to the same source name passed to UseOpenTelemetry and exports those spans directly to Arize AX.

Add a tool

Create WeatherTools.cs for the function tool used by the agent:

static class WeatherTools
{
    [Description("Returns the current weather for a city.")]
    public static string GetWeather(
        [Description("The city to check.")] string city) =>
        $"Sunny and 72°F in {city}.";
}

Run Microsoft Agent Framework

Add the agent invocation to the end of Program.cs:

var result = await agent.RunAsync("What is the weather in San Francisco?");
Console.WriteLine(result);

Run the project from the MicrosoftAgentFramework directory:

dotnet run --project MicrosoftAgentFramework.csproj

Expected output

Arize AX tracing initialized for Microsoft Agent Framework (C#).
Sunny and 72°F in San Francisco.

Verify in Arize AX

Open your Arize AX space and select project microsoft-agent-framework-csharp-example.
You should see a trace with an invoke_agent root span, chat spans for the model calls, and an execute_tool span for GetWeather. The model spans include provider, model, token usage, and message attributes.
If no traces appear, see Troubleshooting.

Confirm spans are actually reaching your Arize AX project. Use whichever fits your workflow — the skill and CLI work for any framework; the SDK check is shown for each language.

Arize skill (agent)
AX CLI
SDK

Install the Arize Skills plugin and let your coding agent check for you:

npx skills add Arize-ai/arize-skills

Then prompt your agent:

Use the arize-trace skill to export and analyze recent traces from my project. Confirm spans are arriving, and summarize any errors or latency issues.

Export recent spans for your project — any rows mean traces are landing:

ax spans export "$ARIZE_PROJECT_NAME" --space "$ARIZE_SPACE_ID" \
  --limit 5 --stdout | jq 'length'

A non-zero count confirms spans reached Arize AX. Run ax auth login first if you have not authenticated. See the ax spans reference.

Query the project’s spans and check that at least one came back.

import os
from arize import ArizeClient

client = ArizeClient(api_key=os.environ["ARIZE_API_KEY"])
resp = client.spans.list(
    project=os.environ["ARIZE_PROJECT_NAME"],
    space=os.environ["ARIZE_SPACE_ID"],
    limit=5,
)
count = len(resp.spans)
print(
    f"{count} span(s) found" if count else "No spans yet — recheck setup"
)

// Reads ARIZE_API_KEY from the environment.
import { listSpans } from "@arizeai/ax-client";

const { data: spans } = await listSpans({
  project: process.env.ARIZE_PROJECT_NAME!,
  space: process.env.ARIZE_SPACE_ID!,
  limit: 5,
});
const count = spans.length;
console.log(
  count ? `${count} span(s) found` : "No spans yet — recheck setup",
);

client, err := arize.NewClient(
    arize.Config{APIKey: os.Getenv("ARIZE_API_KEY")},
)
if err != nil {
    log.Fatal(err)
}
resp, err := client.Spans.List(ctx, spans.ListRequest{
    Project: os.Getenv("ARIZE_PROJECT_NAME"),
    Space:   os.Getenv("ARIZE_SPACE_ID"),
    Limit:   5,
})
if err != nil {
    log.Fatal(err)
}
fmt.Printf("%d span(s) found\n", len(resp.Spans))

SDK span references: Python · TypeScript · Go.

Troubleshooting

No traces in Arize AX. Confirm ARIZE_SPACE_ID and ARIZE_API_KEY are set in the same shell that runs dotnet run, and confirm the exporter endpoint and headers match the example.
No agent spans. The source name passed to UseOpenTelemetry must match the source registered with .AddSource(sourceName).
Wrong project. Confirm the openinference.project.name resource attribute is set to the value of ARIZE_PROJECT_NAME.
Prompts or tool content are missing. Set EnableSensitiveData = true for the agent’s OpenTelemetry configuration. This also records those values in traces, so enable it only when appropriate.
401 from OpenAI. Verify OPENAI_API_KEY is valid and can access gpt-6.1-sol. Replace the model with one available to your account if needed.
Package restore or build fails. Confirm the .NET 10 SDK is installed and that the package versions in the project file match the versions shown above.

OpenTelemetry

LLM Providers

Agent Frameworks

Coding Agents

Platforms

Orchestration

Evaluation

Microsoft Agent Framework for C#

Prerequisites

Launch Arize AX

Install

Configure credentials

Setup tracing

Add a tool

Run Microsoft Agent Framework

Expected output

Verify in Arize AX

Troubleshooting

Resources

Microsoft Agent Framework Documentation

Microsoft Agent Framework Observability

Microsoft Agent Framework GitHub

​Prerequisites

​Launch Arize AX

​Install

​Configure credentials

​Setup tracing

​Add a tool

​Run Microsoft Agent Framework

​Expected output

​Verify in Arize AX

​Troubleshooting

​Resources

Microsoft Agent Framework Documentation

Microsoft Agent Framework Observability

Microsoft Agent Framework GitHub

Prerequisites

Launch Arize AX

Install

Configure credentials

Setup tracing

Add a tool

Run Microsoft Agent Framework

Expected output

Verify in Arize AX

Troubleshooting

Resources