Cal AI's 19-Year-Old Founder Raises $10M for AI Assistant Persona

Zach Yadegari, the 19-year-old co-founder of calorie-tracking app Cal AI, has raised $10 million for his new AI agent startup, Persona. Vine Ventures led the round, with Cory Levy, founder of Z Fellows, and Collective Global participating.

The raise comes just months after a significant exit. In March, MyFitnessPal acquired Cal AI for an undisclosed sum, after Cal AI overtook the older app in the app store rankings. MyFitnessPal told TechCrunch at the time that the deal was big enough to convince Yadegari and his co-founders to sell. The company had pulled in over $30 million in annual revenue in under two years.

Yadegari went to work for his new owner at first, continuing development on Cal AI. He left in June, he tells TechCrunch, and went straight to his next idea. He is building Persona with another co-founder who has yet to be announced.

What is Persona?

Persona is a personal AI assistant, similar to Instinct or Meta's Muse, but with a hardware component: a $179 wearable band. That puts it closer to Bee, the wearable AI device Amazon acquired in 2025. Yadegari says Persona's device differs from Bee in several ways.

The biggest difference is that it won't be ambient AI. The band won't always be listening and recording. It has a button that activates the assistant, or users can set it to wake with a flick of the wrist.

The business stakes here are real. Consumer AI assistants are converging on the same pitch: one agent that orders food, books rides, takes notes, handles travel, and answers email. Meta, Amazon, and OpenAI are all pushing into the category, and hardware gives a startup a persistent touchpoint that phone apps struggle to keep. Yadegari is betting a $179 band beats an app icon.

How does Persona handle privacy?

Persona does not run its AI model or store user data on the device, Yadegari says. The model runs in Persona's cloud, and user data is sent there. The company encrypts data in transit and at rest, and users can delete their data. Persona promises that user conversations stay private and cannot be sold to advertisers or data brokers.

The team is also building safeguards against phishing and prompt-injection attacks, Yadegari says — two areas that AI labs like OpenAI say can plague agents.

Payments get specific protections too. Yadegari promises that Persona's agent can't see a user's credit-card details. Purchases require the user's approval, and payment runs through external providers such as Stripe Link, Stripe's secure wallet designed for use by agents.

Can an ad-funded assistant stay unbiased?

Here's the tension. User data won't be sold to advertisers, but the startup's current business model does rely on ads. Yadegari says the company will show advertised wares during shopping research.

He argues the agent will still present unbiased recommendations, because the agent itself won't know which items are advertised. If someone is researching office chairs, he says, "the agent knows their preferences" and will show chairs matching those preferences — some of them sponsored results.

That claim will face scrutiny. Sponsored results inside an agent's recommendations are exactly where regulators and users are starting to look as AI shopping assistants move from demo to checkout. Whether a model can stay neutral about listings it can't distinguish from organic ones is an open technical question, and Yadegari's answer puts the burden on that separation.

When can you get it?

The bands are expected to be available in December, and an app is in the works. Until then, Persona has launched as a free beta in which users interact with the assistant via iMessage text messages.

Early traction is modest but real. The beta has attracted "a few thousand beta users," Yadegari said, and the band has already generated "five figures in preorder revenue."

Like other consumer AI assistants, Persona can order food or rides, take notes, book travel, answer questions and emails, among other tasks. Yadegari sees all of that collapsing into one product.

"All of the utility apps that you use on your phone day-to-day, whether those are apps for shopping, whether it's Uber, DoorDash, your email — these are all collapsing and will collapse into a single super app powered by an AI assistant," Yadegari said.

Why this founder, why now?

Yadegari's track record is unusually short and unusually profitable. Before Cal AI, he built his first business in the ninth grade and sold it for $100,000 when he was 16. Cal AI followed: two years, $30 million in annual revenue, an acquisition by the incumbent it had beaten in the app store rankings.

His ambition for Persona goes beyond running errands. Eventually, he wants the assistant to be proactive. "It can offer help and solve problems before you even know you have a problem, and overall be more seamless with your life, so that you don't need to stare at a rectangle in your hand all day," he said.

Yadegari will speak at TechCrunch Disrupt, October 13–15 at the Moscone Center in San Francisco, on "How to create viral growth and capitalize on it."

The December band launch is the test. A few thousand iMessage beta users and five figures in preorders won't worry Meta or Amazon. But Yadegari has already built one consumer app that out-ranked an incumbent and sold it — and now he has $10 million and a hardware deadline to try again.