Unless I'm missing something, I cannot download attachments of messages (e.g. images). It seems they need to be download using the API as I cannot find a public URL in the message attachment data. I tried using Request#get, but that also doesn't seem to work?
Example:
msgs = @client.messages
msgs.each do |msg|
@client.get(msg["attachments"].first["path"]) unless msg["attachments"].empty?
end