Microsoft Agent Framework

using Braintrust.Sdk;
using Braintrust.Sdk.AgentFramework;
using Microsoft.Agents.AI;
using Microsoft.Extensions.AI;
using OpenAI;

var braintrust = Braintrust.Sdk.Braintrust.Get();
var activitySource = braintrust.GetActivitySource();

// Trace LLM calls on the chat client
var chatClient = new OpenAIClient(Environment.GetEnvironmentVariable("OPENAI_API_KEY"))
    .GetChatClient("gpt-5-mini").AsIChatClient()
    .AsBuilder()
    .UseBraintrustLLMTracing(activitySource)
    .Build();

var getWeather = AIFunctionFactory.Create(
    (string city) => $"The weather in {city} is sunny, 72°F.",
    "GetWeather",
    "Gets the current weather for a city.");

// Trace tool calls on the agent and wrap each run
var agent = new ChatClientAgent(
        chatClient,
        instructions: "You are a helpful assistant. Use tools when appropriate.",
        name: "WeatherAgent",
        tools: [getWeather])
    .AsBuilder()
    .UseBraintrustFunctionTracing(activitySource)
    .Build()
    .WithBraintrustAgentTracing(activitySource);

var session = await agent.CreateSessionAsync();
var response = await agent.RunAsync("What's the weather like in Seattle?", session);
Console.WriteLine(response.Text);