Getting started

AnyMediator is an in-process mediator for .NET 8 and .NET 10. A caller sends a message to ISender or IPublisher; AnyMediator finds the handler in the dependency injection container and runs it, through any pipeline behaviors you registered.

Install

dotnet add package AnyMediator

The package brings in AnyMediator.Abstractions, which holds only the interfaces. Class libraries that define requests and handlers can reference AnyMediator.Abstractions alone.

Register

Call AddAnyMediator on your IServiceCollection and tell it which assemblies to scan:

using AnyMediator;

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddAnyMediator(cfg =>
{
    cfg.RegisterServicesFromAssemblyContaining<Program>();
});

The scan registers every non-abstract, non-generic class that implements:

Interface	Registered as
IRequestHandler<TRequest, TResponse>	one handler per request type
IStreamRequestHandler<TRequest, TResponse>	one handler per stream request type
INotificationHandler<TNotification>	any number per notification type
IRequestExceptionHandler<TRequest, TResponse, TException>	any number
IRequestExceptionAction<TRequest, TException>	any number

Pipeline behaviors are never scanned: add them with AddOpenBehavior. Pre- and post-processors are scanned only when AutoRegisterRequestProcessors is true. See Configuration.

Send a request

public sealed record GetUser(int Id) : IRequest<User>;

public sealed class GetUserHandler(IUserStore store) : IRequestHandler<GetUser, User>
{
    public Task<User> Handle(GetUser request, CancellationToken cancellationToken)
        => store.FindAsync(request.Id, cancellationToken);
}

Inject ISender wherever you need to dispatch:

app.MapGet("/users/{id}", (int id, ISender sender, CancellationToken ct) =>
    sender.Send(new GetUser(id), ct));

What to inject

Service	Use it to
ISender	send requests (Send) and open streams (CreateStream)
IPublisher	publish notifications (Publish)
IMediator	both, when a class really needs both

Inject the narrowest one: a class that only publishes events should not be able to send commands.

Next steps

• Coming from MediatR? Read Migrating from MediatR.
• Add cross-cutting logic with pipeline behaviors.
• Publish events with notifications.