vulthil-messaging.md

Vulthil.Messaging

Use Vulthil.Messaging to configure messaging pipelines and hosted consumers.

When to use

• Service registration for consumers and queues
• Runtime message handling orchestration

Pattern

• Keep wiring in composition root
• Separate message contracts from processing logic
• Centralize retry/error strategy decisions

Usage

Registering queues and consumers

builder.AddMessaging(messaging =>
{
    messaging.ConfigureQueue("order-events", queue =>
    {
        queue.AddConsumer<OrderCreatedConsumer>();
        queue.UseRetry(retry =>
        {
            retry.Exponential(3, TimeSpan.FromSeconds(1), TimeSpan.FromSeconds(30));
            retry.UseJitter(0.2);
        });
        queue.UseDeadLetterQueue();
    });

    messaging.ConfigureQueue("order-requests", queue =>
    {
        queue.AddRequestConsumer<GetOrderConsumer>();
    });
});

Routing key configuration

messaging.ConfigureMessage<OrderCreatedEvent>(message =>
{
    message.UseRoutingKey(e => $"order.{e.Region}");
    message.UseCorrelationId(e => e.OrderId.ToString());
});

Per-consumer retry override

AddConsumer accepts a configurator; its knob is the consumer's retry policy, which overrides the queue-level default for that consumer alone:

queue.AddConsumer<OrderCreatedConsumer>(c =>
{
    c.UseRetry(r => r.Immediate(5));
});

Binding patterns are configured per queue, not per consumer — use queue.Subscribe<OrderCreatedEvent>("order.eu") (see Messaging — Routing Keys).

Configuration-driven setup

Queue and message settings under Messaging:Queues:* and Messaging:Messages:* are loaded from IConfiguration before the configurator action runs, so a service can be configured entirely via appsettings.json. Code calls merge on top of the loaded values, with code winning on conflict. See Messaging — Configuration-driven Setup.