using System;

using CsvHelper;

using Newtonsoft.Json;

using System.Globalization;

using System.IO;

​

public class Program

{

    public static void Main()

    {

        var txtInput = "a,b,c\n1,2,3\n4,5,6";

        string output;

        using (var reader = new StringReader(txtInput))

            using (var csvReader = new CsvReader(reader, CultureInfo.InvariantCulture))

        {

            var records = csvReader.GetRecords<dynamic>();

            output = JsonConvert.SerializeObject(records, Formatting.Indented);

        }

​

        Console.WriteLine(output);

    }

}