Mandy Moore celebrated the first birthday of her son, August, in a heartwarming video tribute on Instagram.

The 37-year-old “A Walk To Remember” actress uploaded a short clip Sunday showing the little one’s cutest moments, from the time he was a tiny newborn to his more recent adorable snaps and clips.

The video montage shows August, or Gus, yawning as a newborn baby swaddled and wrapped in a colorful blanket. The series of photos also include the baby, wearing sunglasses and being breastfed by his mom who is in her aged makeup look for her TV character Rebecca in "This Is Us."

The slideshow also showed photographs of Gus enjoying a bath with his dad and flashing a toothy smile while wearing colorful onesies in the slideshow, as "Memo To My Son" by Randy Newman being played in the background.

"Gus- Being your mom is a gift beyond my comprehension, a love so fierce and mighty that I know I will never touch the depths of. Happy Birthday to our ever joyful and curious boy!!! You turned on all the lights, Goosey. #thisisgus," Moore wrote.

"High School Musical" star Ashley Tisdale, "Dancing With The Stars" contestant Amanda Kloots and Australian actress Claire Holt shared their birthday wishes for the little boy in the comments. Fans also commented how “perfect” and “sweet” Gus is.

The "Only Hope" singer welcomed Gus three years after she and her husband Taylor Goldsmith exchanged vows in November 2018.

The 37-year-old actress announced the birth of her firstborn in 2021, and wrote on Instagram, "Gus is here. Our sweet boy, August Harrison Goldsmith. He was punctual and arrived right on his due date, much to the delight of his parents. We were prepared to fall in love in all sorts of brand new ways, but it goes beyond anything we could have ever imagined."

In an Instagram story shared Sunday, Moore reflected on meeting her son for the first time. She uploaded a photo of her smiling triumphantly while holding her newborn, and wrote, "The greatest moment of my life, along with every moment since. "We love you to the moon, Goosey!!"

On "This Is Us," Mandy Moore's character Rebecca Pearson is forced to postpone participating in a clinical trial for Alzheimer's treatment because of the coronavirus
On "This Is Us," Mandy Moore's character Rebecca Pearson is forced to postpone participating in a clinical trial for Alzheimer's treatment because of the coronavirus AFP / Jean-Baptiste LACROIX