1.5.18. Capability Matching and Assert

The assert option is not exactly equivalent to the 0-10 based mechanism. Over AMQP 1.0, the client sets the capabilities it desires, the broker sets the capabilities it can offer and when the assert option is on, the client ensures that all the capabilities it requested are supported.

The capabilities sent by the client can be controlled through a nested list within the node map. Note that capabilities are simple strings (symbols in 1.0), not name-value pairs.

If durable is set in the node properties, then a capability of 'durable' is requested (meaning the node will not lose messages if its volatile memory is lost).

If the type is set, then that will also be passed as a requested capability. For example: 'queue' means the node supports queue-like characteristics (stores messages until consumers claim them and allocates messages between competing consumers), 'topic' means the node supports classic pub-sub characteristics.