"Always strive and prosper. RIP Yams," said a post Sunday on the group's official Facebook page
with a black-and-white photo of Yams, whose real name is Steven Rodriguez.
He was 26 years old.
"We bugged out on New Years, I didn't know that would be the last time Seeing my brother," A$AP Ferg, one of the stars who emerged from the A$AP collective, wrote in a post on Instagram
. "R.i.P bro. We all love and Miss you."
The group's record company, RCA Records, said it was "shocked and saddened to hear of the death of A$AP Yams," according to a statement reported by Rolling Stone
"As one of the creative forces behind A$AP Worldwide, Yams' vision, humor and dedication to the members of A$AP Mob will always be remembered," the statement said.
It wasn't immediately clear how Yams had died.
Other hip-hop stars expressed their sadness and paid tribute to his life on social media.
"Rest in peace Yams. A$AP is family," tweeted Drake.
"A.S.A.P YAMS should be remembered as a leader, an innovator and most importantly as an important part of NYC youth culture," wrote Azealia Banks.
Rather than being famous for rapping or mixing, Yams is credited with masterminding the rise of A$AP Mob and launching the careers of A$AP Ferg and the chart-topping A$AP Rocky.
"Rocky's like Luke Skywalker, and I'm Yoda," Yams said in an interview with The New York Times
in 2013, explaining their respective roles.
"R.I.P Yams, I love you brother," Rocky posted on Facebook.
"You were the brilliant mind, you put us on Game, you changed our lives. You changed my life, you changed the world," Ferg wrote on Instagram next to a photo of him and Yams kneeling on stage.
Yams was born to a Dominican mother and a Puerto Rican father, according to The New York Times interview. He grew up on the southern edge of Harlem with a lifelong obsession with hip-hop.
"Yams is the hip-hop encyclopedia," Rocky said in the article. "He's no joke. That's one person I can't front on when it comes to music."