Declare the broker topology from a file Written by the Hub
Builds a RabbitMQ topology from a description, instead of by hand or by letting the engine declare it.
In detail
MailerQ declares what it needs on start-up — the sending queue, the delay ladder, the result queues — so this is for everything beyond that: extra queues for a customer's own consumers, bindings for a second reader of the results, a topology shared between several nodes. For us it competes with a job Hub could do directly through the broker's management API, which is already how the collector talks to it. The tool matters mainly as documentation of what a non-default MailerQ topology looks like.