Minicon.Mediator 1.0.0

Minicon.Mediator

A lightweight, MediatR-API-compatible mediator for .NET — request/response, notifications and pipeline behaviors with exactly one runtime dependency (Microsoft.Extensions.DependencyInjection.Abstractions).

Independent reimplementation by minicon eG. Not affiliated with or endorsed by the MediatR project. "MediatR" is a trademark of its respective owner; the familiar type names (IRequest, INotification, …) are kept for an easy migration, but this package lives in its own Minicon.Mediator namespace.

Install

dotnet add package Minicon.Mediator

Targets net8.0 and net10.0.

Usage

using Minicon.Mediator;
using Microsoft.Extensions.DependencyInjection;

// 1) Register — scans the given assembly for handlers
services.AddMediator(cfg => cfg.RegisterServicesFromAssemblyContaining<Ping>());

// 2) Request / Response
public record Ping(string Message) : IRequest<string>;

public sealed class PingHandler : IRequestHandler<Ping, string>
{
    public Task<string> Handle(Ping request, CancellationToken ct)
        => Task.FromResult($"Pong: {request.Message}");
}

var answer = await mediator.Send(new Ping("hi"));   // "Pong: hi"

// 3) Notifications (fan-out to all handlers)
public record UserRegistered(string Email) : INotification;

public sealed class SendWelcome : INotificationHandler<UserRegistered>
{
    public Task Handle(UserRegistered n, CancellationToken ct) => /* ... */ Task.CompletedTask;
}

await mediator.Publish(new UserRegistered("a@b.de"));

// 4) Pipeline behaviors (logging, validation, transactions, …)
public sealed class LoggingBehavior<TReq, TRes> : IPipelineBehavior<TReq, TRes>
    where TReq : notnull
{
    public async Task<TRes> Handle(TReq req, RequestHandlerDelegate<TRes> next, CancellationToken ct)
    {
        // before
        var res = await next();
        // after
        return res;
    }
}

Migrating from MediatR

In most cases a single replacement is enough:

• using MediatR; → using Minicon.Mediator;
• services.AddMediatR(...) → services.AddMediator(...)
• MediatRServiceConfiguration → MediatorServiceConfiguration

All other type names (IRequest, IRequest<T>, INotification, IRequestHandler<,>, INotificationHandler<>, IPipelineBehavior<,>, ISender, IPublisher, IMediator, Unit) are unchanged.

License

MIT © minicon eG