The first argument is the receiver's service name. It might have been created by

your ``transports`` configuration or it can be your own receiver.

Multiple buses

If you are interested into architectures like CQRS, you might want to have multiple

buses within your application.

You can create multiple buses (in this example, a command and an event bus) like

this:

..code-block::yaml

This will generate the ``messenger.bus.commands`` and ``messenger.bus.events`` services

that you can inject in your services.

Type-hints and auto-wiring

Auto-wiring is a great feature that allows you to reduce the amount of configuration

required for your service container to be created. When using multiple buses, by default,

the auto-wiring will not work as it won't know why bus to inject in your own services.

In order to clarify this, you will have to create your own decorators for your message

buses. Let's create one for your ``CommandBus``::

Last step is to register your service (and explicit its argument) to be able to typehint

your ``CommandBus`` in your services:

..code-block::yaml

Your own Transport