Program.cs

using Microsoft.SemanticKernel;

var openAIChatCompletionModelName = "gpt-3.5-turbo"; // this could be other models like "gpt-4o".
var builder = WebApplication.CreateBuilder(args);

builder.Services.AddKernel();

// This should work for any other service you can decided to use E.g Mistral.
var kernel = builder.Services.AddOpenAIChatCompletion(openAIChatCompletionModelName, Environment.GetEnvironmentVariable("OPENAI_API_KEY"));
var app = builder.Build();

app.MapGet("/WeatherForecast", async (Kernel kernel) =>
{
    int temp = Random.Shared.Next(-20, 55);
    return new WeatherForecast
    (
        DateOnly.FromDateTime(DateTime.Now),
        temp,
        await kernel.InvokePromptAsync<string>($"Short description of weather at {temp} degrees Celsius") // This description will be generated by the AI model for the given temperature.
    );
});
app.Run();

internal record WeatherForecast(DateOnly Date, int TempratureC, string Summary)
{
    public int TemperatureF => 32 + (int)(TempratureC / 0.5556);
}