For those who missed it during the great football weekend, the terms of the deal were not disclosed. See link.
http://www.nba.com/nets/news/2017/09/24/brooklyn-nets-sign-akil-mitchell
Also, there's another link to the right on this page re: Joe Harris
http://www.nba.com/nets/news/2017/09/24/brooklyn-nets-sign-akil-mitchell
Also, there's another link to the right on this page re: Joe Harris