Paige Harris is a hacker who can assist the player in various heists in GTA V and GTA Online.
She's the best hacker available in the former, while she's the second-best in GTA Online for the Diamond Casino Heist (behind Avi Schwartzman). Unsurprisingly, her Client Jobs are heavily related to heists.
Paige Harris' Client Jobs were available since the After Hours update on August 14, 2018. The player has to purchase a Nightclub first and then purchase the Terrorbyte to unlock Paige Harris' Client Jobs in GTA Online.
It will cost the player a sizable amount of money ($1,375,000 for the Terrorbyte plus whatever Nightclub and upgrades the player purchases), but it is worth it if the player is interested in Client Jobs.
Unlocking Paige Harris' Client Jobs in GTA Online
Paige Harris' Client Jobs are available once the player purchases a Nightclub, upgrades related to the Terrorbyte, and the Terrorbyte itself. It'll cost the player several million dollars, but they remain unlocked once the Client Jobs are unlocked. There are six Client Jobs for a player to do in total.
Nightclubs
It doesn't matter which Nightclub the player purchases. The Elysian Island Nightclub that costs $1,080,000 works just as well as the West Vinewood Nightclub that costs $1,700,000.
Likewise, anything between these two Nightclubs should work to unlock Paige Harris' Client Jobs.
Additional customization options for the Nightclub aren't essential for obtaining a Terrorbyte (that unlocks Paige Harris' Client Jobs), except for the optional Terrorbyte Garage and Basement Level B5.
Predictably, it requires the previous basement levels to be purchased (can't have a B5 without B1, B2, etc.).
Terrorbyte
The player can purchase a Terrorbyte from warstock-cache-and-carry.com for $1,375,000. Additional upgrades aren't necessary for unlocking Paige Harris' Client Jobs.
Still, they help the player out in GTA Online (for example, upgrading the ever-oppressive Oppressor Mk II with a Specialized Workshop for $495,000).
Client Job Info
As previously mentioned, there are six client jobs in total. Paige Harris can assign four of them to solo players, with the remaining two being available for groups of at least two players.
Generally, there is a 30-minute cooldown on the mission a player completes, with all other missions receiving a five-minute cooldown in GTA Online.
The two Client Jobs involving groups of players have their own independent cooldowns, allowing players to do multiple Client Jobs without waiting (if they alternate between group and solo Client Jobs). Unlocking the Client Jobs also unlocks Paige Harris as a Heist Crew Member in GTA Online.