Cal AI Founder Raises $10M for Persona, an AI Agent with a Wearable

Overview

Zach Yadegari, the 19-year-old entrepreneur who recently sold his calorie-tracking app Cal AI to MyFitnessPal, has launched a new venture called Persona. The startup is building an AI agent designed to act as a proactive personal assistant, distinct from previous efforts in the space by integrating dedicated hardware.

Persona has secured $10 million in funding led by Vine Ventures, with participation from Z Fellows founder Cory Levy and Collective Global. This investment comes swiftly after Yadegari departed MyFitnessPal in June, signaling continued confidence in his ability to execute on high-impact consumer technology ideas.

"All of the utility apps that you use on your phone day-to-day... are collapsing and will collapse into a single super app powered by an AI assistant." — Zach Yadegari, Founder of Persona

Funding and Leadership Background

Yadegari’s transition from selling Cal AI to founding Persona follows a trajectory of rapid entrepreneurial success. In March, MyFitnessPal acquired Cal AI for an undisclosed sum after the app surged past its predecessor in app store rankings. At the time of the sale, Cal AI had generated over $30 million in annual revenue in under two years.

Although Yadegari and his co-founders initially stayed on to continue developing Cal AI post-acquisition, he left the parent company in June to pursue new opportunities. He is now working with a new, yet-to-be-announced co-founder on Persona.

The latest $10 million round underscores the market interest in Yadegari’s vision. Vine Ventures led the investment, joining existing supporters like Cory Levy and Collective Global. This financial backing allows the team to focus on developing both the software agent and the physical wearable device that will interface with it.

The Persona Hardware and Privacy Model

Persona differentiates itself from competitors like Instinct or Meta’s Muse through its tangible hardware component: a wearable band priced at $179. While similar to Amazon’s Bee device, which was acquired in 2025, Persona’s approach to interaction and data security represents a deliberate departure from ambient AI concepts.

The band features a physical button or a wrist-flick gesture to activate the assistant. This design choice ensures the device does not constantly listen or record ambient sound, addressing one of the primary concerns users have with always-on AI hardware. By requiring active initiation, Persona positions itself as a responsive tool rather than a passive observer.

"Persona doesn’t run its AI model or store user data on the device. Instead, the model runs in Persona’s cloud, and user data is sent there." — Zach Yadegari

Privacy remains a central pillar of the product’s architecture. The company emphasizes that user conversations are encrypted both in transit and at rest. Furthermore, Persona explicitly states that it will not sell user data to advertisers or data brokers, a practice that has drawn scrutiny across the tech industry. Users retain the ability to delete their data entirely, granting them significant control over their digital footprint.

Security Safeguards and Business Model

Beyond basic privacy, Persona is incorporating safeguards against sophisticated cyber threats such as phishing and prompt-injection attacks. These vulnerabilities are known pain points for AI agents, having been highlighted by major labs like OpenAI as critical risks in autonomous systems.

To mitigate financial risk, the assistant cannot view credit card details directly. Purchases must be approved by the user, and payments are processed through external secure providers such as Stripe Link. This integration ensures that sensitive financial information is handled by established, regulated payment infrastructure rather than the AI agent itself.

Despite these privacy protections, Persona’s business model does include advertising. Yadegari explains that the company will display sponsored products during shopping research tasks. However, he maintains that the recommendations will remain unbiased because the agent is designed to prioritize user preferences over sponsorship status. For instance, if a user is researching office chairs, the agent will surface options that match their criteria, with sponsored results blended in based on relevance.

Product Availability and Future Vision

The Persona wearable band is scheduled for release in December, accompanied by a dedicated mobile application currently in development. In the interim, the company has launched a free beta version of the AI assistant accessible via iMessage.

Early traction appears promising, with Yadegari reporting that the beta has attracted several thousand users. Pre-orders for the physical band have already generated five figures in revenue, indicating strong consumer interest despite the device not yet being in customers' hands.

The assistant is designed to handle a wide array of daily tasks, including:

• Ordering food and rides
• Taking notes and managing emails
• Booking travel and answering questions

Yadegari envisions a future where Persona evolves from reactive to proactive, solving problems before the user is even aware of them. The ultimate goal is to reduce reliance on smartphones by creating a seamless layer of assistance that integrates naturally into daily life.

"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." — Zach Yadegari

Yadegari is also set to discuss the mechanics of viral growth and scaling startups at the upcoming TechCrunch Disrupt conference in San Francisco. His journey includes selling his first business for $100,000 at age 16, adding to the narrative of a young founder successfully navigating the competitive AI landscape.