Apple has said that since macOS Mojave is already here, developers should give Mac users even more confidence in their software distributed outside the Mac App Store by submitting it to Apple to be notarised. When users on macOS Mojave first open a notarized app, installer package, or disk image, they’ll see a more streamlined Gatekeeper dialogue and have confidence that it is not known malware.
Apple goes on to add that in order to do this, a developer should download Xcode 10 and submit their software. In an upcoming release of macOS, Gatekeeper will require Developer ID-signed software to be notarised by Apple. It’s easy to get unpublished software notarized with the Export process or xcodebuild. Custom build workflows are supported by the xcrun altool command line tool for uploading, and you can use xcrun stapler to attach the ticket to the package.
To submit software you've already published, upload it using the xcrun altool command line tool. Several file types are supported, including .zip, .pkg, and .dmg, so you can upload the same package you already distribute to users.
