Knock, knock … who’s there? Just “Selling Sunset” star Amanza Smith — serving full birthday energy today … and we’re all here ready to close the deal on her big day!

Amanza’s turning 49 — and you know she’s feeling fine — showing off those bright, colorful fits that spotlight every inch of that bangin’ bod, which you can check out in this gallery.

Whether she’s closing a listing or posing on the beach, this birthday babe crushes it every single time!