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GenRMQ is a set of behaviours meant to be used to create RabbitMQ consumers and publishers. Internally it is using AMQP elixir RabbitMQ client. The idea is to reduce boilerplate consumer / publisher code, which usually includes:

  • creating connection / channel and keeping it in a state
  • creating and binding queue
  • handling reconnections / consumer cancellations

The project currently provides the following functionality:


def deps do
  [{:gen_rmq, "~> 1.3.0"}]


Please check how to migrate to gen_rmq 1.0.0 from previous versions.


More thorough examples for using GenRMQ.Consumer and GenRMQ.Publisher can be found in the examples directory.


defmodule Consumer do
  @behaviour GenRMQ.Consumer

  def init() do
      queue: "gen_rmq_in_queue",
      exchange: "gen_rmq_exchange",
      routing_key: "#",
      prefetch_count: "10",
      uri: "amqp://guest:guest@localhost:5672",
      retry_delay_function: fn attempt -> :timer.sleep(2000 * attempt) end

  def consumer_tag() do

  def handle_message(message) do
GenRMQ.Consumer.start_link(Consumer, name: Consumer)

This will result in:

  • durable gen_rmq_exchange.deadletter exchange created or redeclared
  • durable gen_rmq_in_queue_error queue created or redeclared. It will be bound to gen_rmq_exchange.deadletter
  • durable topic gen_rmq_exchange exchange created or redeclared
  • durable gen_rmq_in_queue queue created or redeclared. It will be bound to gen_rmq_exchange exchange and has a deadletter exchange set to gen_rmq_exchange.deadletter
  • every handle_message callback will executed in separate process. This can be disabled by setting concurrency: false in init callback
  • on failed rabbitmq connection it will wait for a bit and then reconnect

Optionally, you can:

  • specify queue ttl with queue_ttl attribute
  • disable deadletter setup by setting deadletter attribute to false
  • define custom names for deadletter queue / exchange / routing key by specifying deadletter_queue / deadletter_exchange / deadletter_routing_key attributes
  • create a priority queue with queue_max_priority attribute

For all available options please check consumer documentation.


defmodule Publisher do
  @behaviour GenRMQ.Publisher

  def init() do
      exchange: "gen_rmq_exchange",
      uri: "amqp://guest:guest@localhost:5672"
GenRMQ.Publisher.start_link(Publisher, name: Publisher)
GenRMQ.Publisher.publish(Publisher, Jason.encode!(%{msg: "msg"}))

Running tests

You need docker-compose installed.

$ make test

How to contribute

We happily accept contributions in the form of Github PRs or in the form of bug reports, comments/suggestions or usage questions by creating a github issue.

Notes on project maturity

This library was developed as a Meltwater internal project starting in January 2018. Over the next two months it has been used in at least three Meltwater production services.


The MIT License (MIT)

Copyright (c) 2018 Meltwater Inc.