Third party apps and services have been able to connect with the Google Assistant in the States since late last year, through the Actions on Google platform. Compatibility with more languages and regions was promised, and a couple of months ago we got support for it here in the UK, too. Australia is next up. Starting today, developers and businesses down under can integrate their apps with the Google Assistant.
Actions on Google is now available for the Australian Google Assistant was written by the awesome team at Android Police.