Messages sent over AMQP 0-10 are converted by the broker for sending over AMQP 1.0, and vice versa.

The message-id, correlation-id, userid, content-type and content-encoding map between the properties section in 1.0 and the message-properties in an 0-10 header. Note, however, that a 0-10 message-id must be a UUID. This field is skipped when translating a 1.0 message to 0-10 if it does not contain a valid UUID.

The priority field in the header section of a 1.0 message maps to the priority field in the delivery-properties of an 0-10 message. The durable header in a 1.0 message is equivalent to the delivery-mode in the delivery-properties of an 0-10 message, with a value of true in the former being equivalent to a value of 2 in the latter and a value of false in the former equivalent to 1 in the latter.

When converting from 0-10 to 1.0, if no exchange is set, then the reply-to is the routing-key. If the exchange is set then the reply-to address for 1.0 is composed from the exchange and any routing key (separated by a forward slash).

Note that the client assumes the reply-to address is a queue if no type is specified. To ensure that a 0-10 routing-key for an exchange is correctly converted to a 1.0 reply-to, specify the node type in the 0-10 address, for instance 'amq.direct/rk; {node:{type:topic}}', or set the type on the Address instance.

When converting from 0-10 to 1.0, if the 0-10 message has a non-empty destination, then the subject field in the properties of the 1.0 message is set to the value of the routing-key from the message-properties of the 0-10 message. In the reverse direction, the subject field of the properties section of the 1.0 message populates the routing-key in the message-properties of the 0-10 message. Note that the routing-key truncates at 255 characters.

The destination of a 0-10 message is used to populate the 'to' field of the properties section when converting to 1.0, but the reverse translation is not done (as the destination for messages sent out by the broker is controlled by the subscription in 0-10).

The application-properties section of a 1.0 message is converted to the application-headers field in the message-properties of an 0-10 message and vice versa.

When converting reply-to from 1.0 to 0-10, if the address contains a forward slash it is assumed to be of the form exchange/routing key. If it does not contain a forward slash, it is assumed to be a simple node name. If that name matches an existing queue, then the resulting 0-10 reply-to will have the exchange empty and the routing key populated with the queue name. If the name does not match an existing queue, but the name matches an exchange, then the reply-to has the exchange populated with the node name and the routing key left empty. If the node refers to neither a known queue nor exchange then the resulting reply-to will be empty.