The ASB Classic defending champions are returning to Auckland.
2018 Women's champion and current world number nine Julia Goerges and Men's champion Roberto Bautista Agut will be returning to defend their titles next year.
Goerges carried on her sublime form after her win in Auckland, beating two top 20 players (Daria Kasatkina & Anastasija Sevastova) as well as US Open Champion Naomi Osaka, on route to the final of the Charleston Open in April.
The German powerhouse also added another three quarter-final (Moscow, Birmingham, Doha) and two semi-final appearances (New Haven, St Petersburg) to round out her career best year.
Her standout performance came on the grass courts of Wimbledon, where she reached her first Grand Slam semi-final, fighting through a number of three set matches before falling to 7-time Wimbledon Champion Serena Williams.