Offset was all smiles and showing love to fans just moments before he was shot outside a South Florida casino … TMZ has learned.

Witnesses tell us the rapper was inside the Seminole Hard Rock Hotel & Casino in Hollywood, FL around 7:10 PM Monday — moments before the shooting — and he was in great spirits.

We’re told Offset was standing near an exit, looking out toward the valet area while talking on his phone. During that time, fans approached him and he happily engaged.

We’re told he shook hands, posed for photos and chatted briefly with supporters with no hesitation and no signs anything was off. A witness tells us he seemed relaxed and friendly.

Moments later, gunfire erupted outside the valet area.

We broke the story … Offset was transported to a nearby hospital after the shooting. A rep for the rapper tells us he’s “fine” and currently receiving medical care, adding he is stable and being closely monitored.

Seminole, FL PD tells us the incident happened shortly after 7 PM and resulted in non-life-threatening injuries. Two individuals have been detained, and authorities say the situation was quickly contained. The investigation remains ongoing.