Rich Homie Quan was foaming at the mouth, wasn’t breathing and had no heartbeat when his girlfriend called 911 … TMZ has learned.

We obtained the emergency call related to the Atlanta rapper’s death and his girlfriend Amber Williams is frantic as she talks to the dispatcher.

Rich Homie Quan’s girlfriend says he was on the couch in the morning when she took her son to school, so she put a blanket over him … but she says when she got home she noticed he hadn’t moved.

She says she didn’t feel a heartbeat, couldn’t see him breathing and turned him over … resulting in foaming at the mouth.

TMZ broke the story … Rich Homie Quan died Thursday at his Atlanta home, and his body was taken to the Fulton County morgue.

Rich Homie Quan’s family told us they were shattered and heartbroken by his sudden death and were searching for answers.

The cause of death remains unclear, though this new audio sheds some light on the circumstances surrounding Rich Homie Quan’s passing.

RHQ’s death is sending shockwaves through the hip hop world … tributes are pouring in, with Boosie saying he just talked to Quan the other day.