Payton is the son of former Blues and All Blacks first-five Carlos Spencer.
All Blacks Sevens head coach Clark Laidlaw said it's great to have the youngsters, who were all at high school last year, in the the squad.
"We are really excited about for the next couple of seasons, these three young players have lots of potential, it will be great to see them develop as rugby players but personally too on and off the field."
After making his mark in rugby league, Tito-Harris has decided to focus on rugby sevens.
"Xavier has played a lot of rugby league and has had some good opportunities to pursue the sport but has instead chosen to come to here and start his professional career with the sevens for the next couple of seasons. He is skilful, has x-factor on the ball and is an attacking threat. I am looking forward to seeing him mature and develop as a rugby sevens player, he has just turned 18 in camp the other week, which was cool to celebrate with the team."
Tito-Harris said he was excited for the opportunity and is ready to make his mark in the All Blacks Sevens environment.
"I have mostly played rugby league, then played sevens through school. I played at the World Schools Sevens tournament and that is where Clark picked me up. It wasn't an easy decision to sign on, but the culture of the team and the boys was what convinced me.
"I'm definitely enjoying it, there is a lot more running, but getting plenty of help from the boys. One of my biggest goals coming into this team, is setting my sights on the Olympics in Paris in 2024," said Tito-Harris.
Spencer, a product from Hamilton Boys' High School, has no shortage of talent.
An exceptional fullback and cricketer in his own right, he has taken up the challenge of rugby sevens.
Laidlaw said the 18-year-old has impressed coaches with his ability to learn the sevens format.
"Obviously really good stock, coming from his dad Carlos Spencer. He is a great athlete, typical Hamilton Boys' knows how to work hard, knows how to train really well and is a great product of their system. He has a good skill set, a beautiful passer, a big, tall rangy athlete.
"He has not played a lot of sevens, he has played a lot of cricket over the summer and is outstanding. We are excited how quickly he can pick up the game, and his ability to play sevens. It has been great to see his skills develop during induction over the last couple of weeks," said Laidlaw.
Spencer said he was excited for the opportunity and is eager to learn from a group of talented individuals both on and off the field.
"I haven't played much sevens, mainly fifteens, but I am glad I have come to sevens, the boys and the culture is great. It hasn't been easy; it hasn't been that hard either, it is still rugby. Been a fullback in fifteens, mounts well shifting to sevens."
Looking ahead to the future, Spencer also has his sights set on the Olympics squad.
"To go to the Olympics is my dream, which is the same for everyone playing in rugby sevens. It's a huge sporting event," said Spencer.
Tepaea Cook-Savage, has also signed on with the All Blacks Sevens at the end of last year, following his debut in Cape Town.
"He has played a bit of sevens, with Waikato, in the National Sevens and for their NPC side. He is a little bit more mature than Spencer and Tito-Harris but is an outstanding young professional and we have been blown away with his diligence and ability to pick up information quickly. This has been demonstrated already when he played in Cape Town, he never really looked out of place. We have high hopes with him coming into our outside backs and looking forward to seeing what he will achieve," said Laidlaw.
The 21-year old said he is grateful for the knowledge and experience he has had thus far.
"It has been an awesome couple of months. Debuting in Cape Town was unreal. I'm grateful to be able to go to work alongside so many talented and experienced players. I'm always learning and the experience I have already gained from playing in Cape Town has been invaluable. I am looking forward to the 2023 season."
The All Black Sevens will compete at the New Zealand Sevens leg of the World Series in Hamilton this weekend, the final World Series tournament to be hosted in Aotearoa.