XForge.MediatR.OpenTelemetry 1.0.7

XForge.MediatR

Simple, fluent, in-process mediator for .NET with CQRS, pipeline behaviors, and local events.

Why XForge.MediatR?

A modern alternative to MediatR with explicit CQRS, ValueTask contracts, behavior ordering, built-in resilience, and TestableMediator — all under MIT license.

Quick Start

dotnet add package XForge.MediatR.DependencyInjection

// 1. Define a query
public record GetOrder(int OrderId) : IQuery<OrderDto>;
public record OrderDto(int Id, string Customer, decimal Total);

// 2. Implement the handler
public class GetOrderHandler : IRequestHandler<GetOrder, OrderDto>
{
    public ValueTask<OrderDto> Handle(GetOrder request, CancellationToken ct)
        => ValueTask.FromResult(new OrderDto(request.OrderId, "Acme Corp", 250.00m));
}

// 3. Register and use
builder.Services.AddXForgeMediator(cfg =>
{
    cfg.RegisterHandlersFrom<Program>();
    cfg.UseDefaults(); // Validation + Logging + Metrics
});

app.MapGet("/orders/{id}", async (int id, IXForgeMediator mediator) =>
    Results.Ok(await mediator.Send(new GetOrder(id))));

Packages

Key Features

• CQRS Explícito — ICommand<T>, IQuery<T>, IEvent with semantic separation
• Flat Pipeline — behaviors with explicit ordering (IOrdered) and filtering (UseFor<T>, UseWhen)
• Built-in Behaviors — validation, logging, metrics, retry, circuit breaker, rate limiter, concurrency limiter, exception handling, pre/post processors
• Result<T> — typed success/failure without exceptions
• Streaming — IStreamRequest<T> with IAsyncEnumerable<T> and pipeline support
• TestableMediator — builder pattern for testing without DI container
• Source Generator — compile-time handler registration, zero reflection at startup
• Roslyn Analyzer — XFMR001 (duplicate handler), XFMR002 (void mismatch), XFMR003 (event handler return type)
• OpenTelemetry — vendor-agnostic traces and metrics
• Multi-TFM — targets net8.0, net9.0, net10.0

Built-in Behaviors

Performance

Benchmarked on .NET 10.0.8, x64 RyuJIT AVX2 against MediatR 14.1.0 and Mediator 3.0.2 (source-generator):

Highlights:

• Send 1.18x faster than MediatR with 59% less allocation (120 B vs 296 B)
• Publish 2.43x faster than MediatR with 14x less allocation
• Cold Start 29x faster than MediatR — ideal for serverless
• Zero tracing overhead — ActivitySource short-circuits when no listeners

See Performance & Benchmarks for full details.

Documentation

• Manual (pt-br) — Complete Portuguese manual with 25 sections
• Manual (en-us) — Complete English manual
• CHANGELOG.md — Release history
• Architecture — Package dependency graph and design decisions

Requirements

License

MIT — Copyright (c) XForge