Message Structure

Libbitcoin messages conform to a uniform message structure implemented using ZeroMQ. ZeroMQ imposes its own structure on messages, described at a high level below.

Frame

The fundamental unit of a message is a frame. A frame is a length-specified set of bytes.

[----frame-----]

Message

A message is a set of frames that make up an envelope and body.

[---envelope---]
[-----body-----]

Envelope

An envelope may contain addressing frames (route) and an empty frame (delimiter).

[----route1----]
[----route2----]
[--------------]

Libbitcoin Query Message

A libbitcoin query message (request and response) is a ZeroMQ message where the body contains a command frame and a payload frame. The envelope is generally hidden from the implementation by ZeroMQ.

[---envelope---]
[---command----]
[---payload----]