Muonroi.Messaging.Abstractions 1.0.0-alpha.16

Muonroi.Messaging.Abstractions

Vendor-neutral message bus contracts — IMuonroiMessageEnvelope, domain events, saga, outbox, and routing interfaces — that decouple your domain from any broker or transport library.

This package ships contracts only — no runtime behavior, no DI registrations, and no dependency on any message-bus library. Your domain code references these interfaces and records; the concrete transport wiring lives in the implementation package Muonroi.Messaging.MassTransit.

Installation

dotnet add package Muonroi.Messaging.Abstractions --prerelease

Quick Start

Implement a domain event and wire up a saga state — both depend only on this abstractions package:

using Muonroi.Messaging.Abstractions.Contracts;
using Muonroi.Messaging.Abstractions.Events;

// 1. Define a domain event (implement IMDomainEvent via the provided base classes)
public record OrderCreatedEvent(Guid OrderId, string Product, decimal Total);

// 2. Publish with a typed envelope
var envelope = new MuonroiMessageEnvelope
{
    TenantId   = "tenant-42",
    UserId     = "usr-001",
    CorrelationId = Guid.NewGuid().ToString("N"),   // auto-generated if omitted
    SentAt     = DateTimeOffset.UtcNow              // auto-generated if omitted
};

// 3. Implement a tenant-aware saga state
public class OrderSaga : IMuonroiSaga
{
    public Guid     CorrelationId        { get; set; }
    public string?  TenantId             { get; set; }
    public DateTime CreationTime         { get; set; }
    public DateTime? LastModificationTime { get; set; }
}

// 4. Implement a message router to redirect or dead-letter messages
public class TenantRouter : IMessageRouter<OrderCreatedEvent>
{
    public int    Order => 10;
    public string Code  => "TENANT_ROUTER";

    public Task<IRoutingDecision> RouteAsync(
        OrderCreatedEvent message,
        IRoutingContext context,
        CancellationToken ct = default)
    {
        if (string.IsNullOrEmpty(context.TenantId))
            return Task.FromResult(RoutingDecision.DeadLetter("Missing tenant"));

        return Task.FromResult(RoutingDecision.PassThrough);
    }
}

For end-to-end runtime behavior — broker setup, consumers, outbox relay, and telemetry — see Muonroi.Messaging.MassTransit and the Quickstart.Messaging sample.

Features

• IMuonroiMessageEnvelope / MuonroiMessageEnvelope — immutable message envelope carrying TenantId, UserId, Username, CorrelationId, AccessToken, and SentAt
• Domain event base classes — MEntityCreatedEvent<T>, MEntityChangedEvent<T>, MEntityDeletedEvent<T>, MEntitiesCreatedEvent<T>, MEntitiesChangedEvent<T>, MEntitiesDeletedEvent<T> implementing IMDomainEvent
• Internal mediator events — parallel INotification-based variants for in-process pub/sub via Muonroi.Mediator
• IMuonroiSaga — vendor-neutral saga state contract (tenant-scoped, CorrelationId primary key, timestamps); bridges to MassTransit.ISaga in the adapter package
• IMessageRouter<TMessage> / IRoutingContext — pluggable, ordered routing pipeline that returns an explicit IRoutingDecision
• RoutingDecision — immutable record with PassThrough, RedirectTo(address), and DeadLetter(reason) factory methods
• IMessageRoutingRule<TMessage> — legacy approve/reject routing rule (extend IRule<TMessage> for FactBag-aware evaluation)
• IOutboxRelayService — contract for background outbox relay (RelayPendingAsync)
• EventOutbox / IEventOutboxStore — outbox entity and persistence contract with Pending, Published, Failed statuses
• [Idempotent] — attribute marking a consumer class as requiring inbox-based idempotent processing
• MessageBusTelemetryDescriptor — ITelemetryDescriptor exposing the ActivitySource and Meter names for OpenTelemetry wiring

API Reference

Samples

• Quickstart.Messaging — full messaging demo: IMessageRouter implementation, MuonroiConsumerBase<T> consumers, AddMessageBus() (RabbitMQ) or in-memory fallback, and outbox relay

Compatibility

• Target framework: net8.0
• License: Apache-2.0 (OSS)

Related Packages

• Muonroi.Messaging.MassTransit — runtime implementation: AddMessageBus(), AddOutboxRelay(), MuonroiConsumerBase<T>, RabbitMQ transport, filters, and OpenTelemetry
• Muonroi.Core.Abstractions — MEntity base class used by domain event generics
• Muonroi.Tenancy.Abstractions — ITenantScoped extended by IMuonroiSaga
• Muonroi.Mediator — INotification used by in-process internal event variants

License

Apache-2.0. See LICENSE-APACHE for the full text.