Zach Yadegari, the 19-year-old co-founder behind the calorie tracker Cal AI, has raised $10 million for his new venture, Persona. Vine Ventures led the funding round, with Cory Levy from Z Fellows and Collective Global also participating.
This move comes shortly after Cal AI was acquired by MyFitnessPal in March. The older app bought the younger company for an undisclosed sum after Cal AI overtook its predecessor in app store rankings. MyFitnessPal told TechCrunch at the time that the deal was significant enough to prompt a sale, noting the startup had generated over $30 million in annual revenue in less than two years.
Yadegari and his team initially joined MyFitnessPal to continue development on Cal AI. He departed in June to focus on his next project. He is now working with another co-founder who has not yet been named.
Persona functions as a personal AI assistant, comparable to Instinct or Meta’s Muse, but includes a hardware element. A wearable band priced at $179 will be available soon.
This approach mirrors Bee, the wearable AI device Amazon acquired in 2025, though the hardware differs. Yadegari states the device will not operate as ambient AI. It does not constantly listen or record. Instead, a button activates the assistant, or the user can trigger it by flicking their wrist.
Privacy is a central design element. The AI model and user data do not reside on the device. Processing happens in the cloud, with data encrypted during transmission and while stored. Users retain the option to delete their information.
The company promises that conversations remain private and are not sold to advertisers or data brokers.
Additional safeguards protect against phishing and prompt-injection attacks, issues that AI labs like OpenAI frequently cite as challenges for agents.
The assistant cannot view credit card details. Purchases require explicit user approval and are processed through external providers such as Stripe Link. This is Stripe’s secure wallet designed for agent use.
While user data is not sold, the startup’s current business model relies on advertising. Yadegari says the company will display ads during shopping research. However, the agent presents unbiased recommendations because it does not know which items are sponsored. If a user researches office chairs, the assistant knows their preferences and shows matching options, some of which are sponsored results.
The bands are scheduled for release in December, with an app currently in development. Persona has launched as a free beta accessible via iMessage text messages. Yadegari reports the beta has attracted a few thousand users. Preorders for the band have already generated five figures in revenue.
Like other consumer AI assistants, Persona can order food or rides, take notes, book travel, and answer questions and emails.
Yadegari believes daily utility apps are collapsing into a single super app powered by an AI assistant. He cites shopping apps, services like Uber and DoorDash, and email clients as examples of this trend.
He aims to make the tool more proactive in the future. The goal is for the system to offer help and solve problems before the user realises they have a problem, reducing the need to stare at a phone screen all day.
Yadegari will speak at TechCrunch Disrupt on “How to create viral growth and capitalize on it.” The event runs October 13-15 at the Moscone Center in San Francisco. Before Cal AI, he built his first business in the ninth grade and sold it for $100,000 at age 16.
What it means
The funding signals that investors are willing to back consumer AI hardware despite the crowded market. The focus on a button-activated device rather than constant listening addresses privacy concerns that often block adoption of wearable assistants.
