// MessageReceivedHandler.cs using System; using MediatR; using MediatRSample.Notifications; namespace MediatRSample; public class MessageReceivedHandler : INotificationHandler { public async Task Handle(MessageReceivedNotification notification, CancellationToken cancellationToken) { Console.WriteLine($"MediatR works! (Received a message by {notification.Message.Author.Username})"); // Your implementation } }