Flux.Messaging 2.0.1

Flux.Messaging

Flux.Messaging is a messaging framework for .NET designed for Clean Architecture, DDD, and distributed systems.
It provides a unified model for:

• Publish / Subscribe (fire-and-forget)
• Distributed Command Bus
• Strongly-typed handlers
• Pluggable transports (InMemory, AMQP, etc.)

Flux.Messaging does not try to hide messaging complexity — it structures it properly.

Key Features

• Clear separation between Bus, Dispatcher, and Transport
• First-class support for distributed request-response
• Contract-first design
• DDD / CQRS / Event-Driven friendly
• No dependency on ASP.NET
• Ready for AMQP 1.0 (Qpid, Azure Service Bus, etc.)
• InMemory transport for testing and local development

Packages

Benchmarks

BenchmarkDotNet v0.15.8, Linux Debian GNU/Linux 13 (trixie)
Intel Xeon CPU E5-2680 v4 2.40GHz, 1 CPU, 28 logical and 14 physical cores
.NET SDK 10.0.103
  [Host]     : .NET 10.0.3 (10.0.3, 10.0.326.7603), X64 RyuJIT x86-64-v3
  DefaultJob : .NET 10.0.3 (10.0.3, 10.0.326.7603), X64 RyuJIT x86-64-v3

Core Concepts

Publish (Event)

• Fire-and-forget
• Multiple handlers supported
• No response expected

Send (Command)

• Command (CQRS)
• Exactly one handler
• Can cross process and service boundaries
• No response expected (Expects ACK)

Installation

dotnet add package Flux.Messaging

Basic Setup (InMemory)

services.AddFluxMessaging()
        .UseInMemory();

Publish (Event)

Event definition

public record ProductAdded(Guid ProductId);

Handler

public sealed class ProductAddedHandler : IMessageHandler<ProductAdded>
{
    public Task HandleAsync(ProductAdded message, CancellationToken ct = default)
    {
        Console.WriteLine($"Product added: {message.ProductId}");
        return Task.CompletedTask;
    }
}

Publish

await messageBus.PublishAsync(new ProductAdded(productId));

Send

Command

public sealed record ReserveStockCommand(Guid ProductId, int Quantity);

Handler

public sealed class ReserveStockHandler : ICommandHandler<ReserveStockCommand>
{
    public Task HandleAsync(ReserveStock request, CancellationToken ct = default)
    {
        Console.WriteLine($"Reserving product {request.ProductId}.");
        return Task.CompletedTask;
    }
}

Send

await messageBus.SendAsync(new ReserveStock(productId, 2));

Architecture Overview

Application
 └─ IMessageBus
      ├─ Send (Command)
      └─ Publish (Event)

Infrastructure
 ├─ ITransport (AMQP, InMemory, etc.)
 └─ IMessageDispatcher

• Bus: public API
• Dispatcher: resolves handlers
• Transport: delivers envelopes

The transport does not know handlers.
The dispatcher does not know the transport.

Cross-language interoperability

Flux.Messaging is .NET-first, but transport-agnostic.

Other languages can:

• Consume AMQP envelopes
• Deserialize the payload

No framework dependency is required.

Testing

The solution includes behavior-focused tests:

• Concurrency
• Multiple handlers
• Fault tolerance
• Dispatch correctness

License

This project is licensed under the Apache License, Version 2.0.
See the LICENSE file for details.