Foundatio.RabbitMQ

Foundatio provides RabbitMQ messaging for pub/sub with durable delivery. View source on GitHub →

Overview

Implementation	Interface	Package
RabbitMQMessageBus	IMessageBus	Foundatio.RabbitMQ

Installation

dotnet add package Foundatio.RabbitMQ

Usage

using Foundatio.Messaging;

var messageBus = new RabbitMQMessageBus(o =>
{
    o.ConnectionString = "amqp://guest:guest@localhost:5672";
    o.Topic = "events";
});

await messageBus.SubscribeAsync<OrderCreated>(async order =>
{
    Console.WriteLine($"Order created: {order.OrderId}");
});

await messageBus.PublishAsync(new OrderCreated { OrderId = 123 });

Configuration

Option	Type	Required	Default	Description
ConnectionString	string	✅		RabbitMQ connection string
IsDurable	bool		true	Durable messages
DeliveryLimit	long		2	Max delivery attempts
AcknowledgementStrategy	AcknowledgementStrategy		FireAndForget	Ack strategy
PrefetchCount	ushort		0	Consumer prefetch count

For additional options, see RabbitMQMessageBusOptions source.

Delayed message delivery

You can schedule delivery using DeliveryDelay on publish options (see the messaging guide).

Behavior depends on the broker and the deprecated plugin:

1. RabbitMQ before 4.3 with the plugin installed — If rabbitmq_delayed_message_exchange is present, Foundatio uses it and logs a deprecation warning at startup. The plugin is archived and will not work on RabbitMQ 4.3 and later.
2. RabbitMQ before 4.3 without the plugin — Delayed sends fall back to the in-memory scheduler in MessageBusBase. Not durable across process restarts.
3. RabbitMQ 4.3 and later — The delayed-exchange probe is skipped (the plugin is incompatible). The same in-memory fallback applies automatically.

For durable delayed delivery on newer brokers, plan a migration (for example TTL + dead-letter exchanges or an external scheduler). See the Foundatio.RabbitMQ README for the full note.

Next Steps

• Quorum Queue Migration - Migrate from classic to quorum queues
• Messaging Guide - Pub/sub patterns and best practices
• Serialization - Configure serialization