It took a bit of time but Apple has finally released the Mac counterpart to be able to use Messages in iCloud. macOS High Sierra 10.13.5 brings with it the feature that will let you sync your chats across your Apple devices. This means, if you delete a message on your iMac, you can expect this to disappear on your iPhone. It’ll also give you access to your entire chat history if you’re setting up a new Mac device. No other big standout feature is included in the update, outside of the usual security and bug fixes.
Source: Engadget