Alex Bass becomes Bradford City's fourth arrival of January transfer window
Bass, 23, has joined on loan for the remainder of the 2021-22 campaign.
The 6ft 3in custodian has made seven appearances in all competitions for Pompey this term.
Sam Hornby is currently the first-choice in goal for the Bantams, having replaced Richard O'Donnell in early December.
On bringing in Bass, Adams said: “Alex is a player I have watched for a number of years at Portsmouth, so I am pleased to be able to bring him to the club.
“He came through the youth system at Portsmouth when I was manager of Plymouth Argyle. He is very highly thought of there and arrives with me having monitored his progress closely.
“Alex has experience of playing in League One with Portsmouth this season, and carries a lot of attributes I value in a goalkeeper, so I am looking forward to seeing him perform at Bradford City.”
Bass said: “It is a pleasure to be here. The manager has been watching me for a while and spoke about the opportunity to come to Bradford City, and it was one I was delighted to take.
“Playing in front of vocal supporters is something I am used to from my time at Portsmouth. I am looking forward to playing football in front of a great fanbase up here, and taking on a new challenge. I cannot wait to get going.
“I have a couple of days of training now to get to know the boys and build relationships with everyone, before getting ready to attack the game on Tuesday.”
Bass is the club's fourth January arrival following the earlier additions of Matty Daly, Jamie Walker and Dion Pereira.