Kate Hudson, Gwyneth Paltrow Share Amazing Photo Booth Pictures from Inside Jennifer Aniston's 50th Birthday Bash
The 'Friends' Cast: Where Are They Now?

One of Jen's "Friends" costars and Katy Perry also popped up in the photos ... Brad Pitt, however, did not.

Jennifer Aniston was surrounded by her friends ... and at least one of her "Friends" ... as she celebrated her 50th birthday this weekend in Los Angeles.

The actress' party generated major headlines on Sunday morning, after ex-husband Brad Pitt was photographed heading into the soiree, which was also attended by big names like Gwyneth Paltrow, Katy Perry, Sandra Bullock, Reese Witherspoon, Lisa Kudrow, Courteney Cox, John Mayer, Barbra Streisand, David Arquette, Robert Downey Jr., Ellen DeGeneres and Diane Keaton.

While we don't have any photos of Pitt inside the event, a few of Jen's celebrity guests broke the "No Social Media" rule -- "with permish," according to Kate Hudson -- to share some pictures from the party's photo booth.

Hudson, Paltrow, Derek Blasberg, Jennifer Meyer and Gucci Westman posted tributes to Jen, along with some choice pictures, on their Instagram pages over the weekend. "Love these ladies. Celebrated this beauty last night ✨Happy Bday JA! We all love you sooo," wrote Hudson. "Happy birthday (last night and tomorrow) to #jenniferaniston our ray of sunshine, example of perpetual goodness," Paltrow captioned her photos, "We love you so much and you make 50 LOOK 🔥"

"There were old friends and new friends and actual Friends and everyone was overjoyed to celebrate this perpetual ray of sunshine: Happy birthday, Jen," wrote Blasberg.

See all the photos below: