Retained Events

When publishing an event, the publisher can set an option (retain=True) in the PublishOptions which will cause the Broker to retain the event being published as the most-recent event on this topic.

Note that Event History is similar to this feature, but not the same.

No configuration is required in Crossbar in order to take advantage of this; it is up to the publisher.

Retrieving an Event

Upon subscription, a client can pass get_retained=True in the SubscribeOptions. If there is any retained event, it will be immediately sent to the subscriber.


There is a completely-worked example in the Autobahn-Python repository.