Zach Yadegari, the 19-year-old co-founder of calorie tracking app Cal AI, has launched Persona, a new AI agent startup, and already raised $10 million. Vine Ventures led the round, with Z Fellows founder Cory Levy and Collective Global participating. The funding follows the March acquisition of Cal AI by MyFitnessPal for an undisclosed sum. Yadegari and his co-founders stayed on to develop Cal AI after the deal, but he left the larger company in June and immediately started work on Persona with another co-founder who has not yet been announced.

Persona is a personal AI assistant similar to Instinct or Meta’s Muse, but it includes a hardware component: a $179 wearable band expected to be available in December. The band differs from Amazon’s Bee wearable AI device in that it is not ambient AI and will not always be listening and recording. Instead, users activate the assistant with a button or by flicking their wrist. The AI model runs in Persona‘s cloud rather than on the device, and user data is sent there, protected by encryption in transit and at rest. Users can delete their data, and the company says conversations will not be sold to advertisers or data brokers.

The team is also building safeguards against phishing and prompt-injection attacks, which Yadegari identifies as common problems for agents. Persona‘s agent cannot see a user’s credit-card details, and purchases require user approval, with payment handled through external providers such as Stripe Link, Stripe’s secure wallet designed for agent use. Although user data is not sold to advertisers, Persona‘s current business model relies on ads. The company will show advertised products during shopping research, but Yadegari says the agent will present unbiased recommendations because it will not know which items are sponsored.

Persona has launched as a free beta product where users interact with the assistant via iMessage text messages, attracting a few thousand beta users. The band has generated five figures in preorder revenue. Like other consumer AI assistants, Persona can order food or rides, take notes, book travel, and answer questions and emails. Yadegari envisions utility apps collapsing into a single super app powered by an AI assistant, and eventually hopes Persona will become more proactive, offering help before users realize they have a problem. Yadegari previously built his first business in ninth grade and sold it for $100,000 at age 16.