Fortigate & Fortianalyzer

I need a way to tie user activity with the fortigate firewall logs.  I have source IP information but I need a way to also collect which AD user is doing that.  I have looked at some of the utilities on the download page but those look like SSO type things.  I dont need users to sign-in or authenticate, but I do need the log files to show per-user activity.  We are using 70F's on 7.6.4 firmware.

Palo Alto Networks products allow this with either a USER-ID agent or CID setup.  I need the fortinet equivalent.