Atya.Messaging.Abstractions 1.1.0

Atya.Messaging.Abstractions

Transport-agnostic messaging contracts for publishers, consumers, subscriptions, and envelopes in Atya services.

Overview

Atya.Messaging.Abstractions defines the small contract layer shared by Atya messaging transports. It models message publishers, consumers, consumer registries, subscriptions, and immutable envelopes without binding applications to a broker, serializer, host, or dependency injection container.

The package intentionally does not implement a transport. Atya.Messaging.InMemory proves these contracts for tests and local development in the same release cycle.

Features

• Publisher, consumer, and consumer registry interfaces with cancellation-aware ValueTask methods.
• Immutable message envelopes with message id, optional correlation id, and copied headers.
• Publish options for transport-neutral metadata.
• Subscription contracts for removing registered consumers.
• No broker-client, DI, serialization, or hosting dependency.

Installation

dotnet add package Atya.Messaging.Abstractions

Install-Package Atya.Messaging.Abstractions

<PackageReference Include="Atya.Messaging.Abstractions" Version="<latest-stable>" />

Quick Start

using Atya.Messaging.Abstractions;

var envelope = MessageEnvelope.Create(
    "customer.created",
    new MessagePublishOptions(
        messageId: "message-1",
        correlationId: "correlation-1",
        headers: new Dictionary<string, string>
        {
            ["tenant"] = "acme",
        }));

Console.WriteLine(envelope.MessageId);
Console.WriteLine(envelope.Message);
Console.WriteLine(envelope.CorrelationId);

Feature Tour

Implement a publisher:

using Atya.Messaging.Abstractions;

public sealed class CustomerEventPublisher(IMessagePublisher<string> publisher)
{
    public ValueTask PublishAsync(string message, CancellationToken cancellationToken = default)
    {
        return publisher.PublishAsync(
            message,
            new MessagePublishOptions(correlationId: "request-123"),
            cancellationToken);
    }
}

Implement a consumer:

using Atya.Messaging.Abstractions;

public sealed class CustomerEventConsumer : IMessageConsumer<string>
{
    public ValueTask ConsumeAsync(
        MessageEnvelope<string> envelope,
        CancellationToken cancellationToken = default)
    {
        Console.WriteLine(envelope.Message);
        return ValueTask.CompletedTask;
    }
}

Consumer failure semantics are transport-neutral: a normal return acknowledges handling, while an exception indicates handling failed and the transport may negatively acknowledge or redeliver the message.

Error Codes

This package does not define Result error codes. Invalid programmer input is rejected with standard .NET argument exceptions through Atya.Foundation.Guards.

Why These Dependencies

• Atya.Foundation.Abstractions keeps this package aligned with the foundation contract layer.
• Atya.Foundation.Guards provides consistent argument validation for public entry points.

Links

• Repository: https://github.com/AtyaLibraries/Messaging.Abstractions
• NuGet: https://www.nuget.org/packages/Atya.Messaging.Abstractions
• Samples: https://github.com/AtyaLibraries/Messaging.Abstractions/tree/development/samples
• License: https://github.com/AtyaLibraries/Messaging.Abstractions/blob/development/LICENSE