The former Doncaster midfielder becomes manager Grant Black's second signing at the club.
James, 21, came through the Doncaster youth system and made his first-team debut for Rovers in 2017.
Black said: “Speaking with Morgan, I was impressed with his attitude to football and life in general. He’s a grafter who wants to get better in everything he does.
“After seeing him play for us in the friendly match at Pinxton on Saturday, I thought that he would be perfect for us.
“He has so much technical ability on the ball and is like a dog without it.
“He fits in with what we want in a player and is the kind of player we want representing Belper Town
“He can play anywhere in midfield and will chip in with goals so we are really looking forward to having him with us.”