oqtane.framework/Oqtane.Shared/Models/ModelBase.cs

using System;

namespace Oqtane.Models
{
    public class ModelBase : IAuditable
    {
        public string CreatedBy { get; set; }
        public DateTime CreatedOn { get; set; }
        public string ModifiedBy { get; set; }
        public DateTime ModifiedOn { get; set; }
    }
}