C#

using System;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Text.Json;
using System.Threading.Tasks;

class Program
{
    // Reutilizamos una sola instancia de HttpClient durante toda la aplicación
    private static readonly HttpClient Client = new HttpClient
    {
        Timeout = TimeSpan.FromSeconds(10)
    };

    static async Task Main()
    {
        Client.DefaultRequestHeaders.UserAgent.ParseAdd("findic-docs-dotnet/1.0");
        Client.DefaultRequestHeaders.Accept.Add(
            new MediaTypeWithQualityHeaderValue("application/json")
        );

        try
        {
            using HttpResponseMessage response = await Client.GetAsync(
                "https://findic.cl/api/"
            );
            response.EnsureSuccessStatusCode();

            string json = await response.Content.ReadAsStringAsync();
            using JsonDocument document = JsonDocument.Parse(json);
            JsonElement uf = document.RootElement.GetProperty("uf");

            Console.WriteLine($"Fecha: {uf.GetProperty("fecha").GetString()}");
            Console.WriteLine($"Valor UF: $ {uf.GetProperty("valor").GetDecimal()}");
        }
        catch (HttpRequestException error)
        {
            Console.WriteLine($"Error en la solicitud: {error.Message}");
        }
    }
}