A boy who bonded with Biden over stuttering will write a children’s book.

They bonded nearly a year ago after Joseph R. Biden Jr. bent down to greet Brayden Harrington, a 13-year-old boy who stutters, at a campaign stop in New Hampshire.

“Don’t let it define you,” Mr. Biden said, squeezing Brayden’s shoulder and looking him in the eye. “You are smart as hell.”

Months later, Brayden spoke at the Democratic National Convention, a remarkable display of bravery and vulnerability that has been viewed hundreds of thousands of times online.

Now, Brayden plans to tell his story in a picture book, “Brayden Speaks Up,” which will be published on Aug. 10 by HarperCollins Children’s Books, the publishing company announced.

The book will be illustrated by Betty C. Tang. Harper Collins said that it was a two-book deal and that Brayden’s agent was David Vigliano at Vigliano Associates. Next year, Brayden plans to write a novel for children ages 8 to 12, HarperCollins said.

The announcement came as Brayden took part in the inaugural celebration for Mr. Biden on Wednesday night, reading aloud a famous passage from John F. Kennedy’s inaugural address: “Ask not what your country can do for you — ask what you can do for your country.”

“When I learned I had the opportunity to speak at the Democratic National Convention, I was so nervous!” Brayden said in a statement. “What got me through and helped motivate me was knowing I could be a voice for other children who stutter as well as anyone else who has faced challenges. I only hope my story provides a little extra support and motivation for those that need it.”

Mr. Biden has spoken openly about the “terrible fear and frustration” he has experienced as a result of his stutter. He has said that it has embarrassed him and made him question himself and his abilities. And he has said that he tells young people who stutter that, if they persevere, they can overcome the challenge and discover new skills and strengths.

“I promise you,” Mr. Biden wrote in a letter to the Stuttering Foundation in 2015, when he was vice president, “you have nothing to be ashamed of, and you have every reason to be proud.”