The privacy pivot

If you’re lowkey tired of feeling like every AI assistant is basically a spy for big tech, listen up. Sigil Wen, a 19-year-old Thiel Fellow and self-taught coder, just dropped an invite-only beta for his new AI assistant, Underdog.

Real talk: most current AI assistants operate by sending your data to massive server farms. This means your search history, financial data, and even stuff about your family could be used to train models or sold to advertisers. Underdog takes a different approach. It runs entirely on your device—meaning your data never leaves your Mac or Windows PC (with Linux and mobile support on the way).

Under the hood

So, how does it actually run? Wen built an engine called Husky, which optimizes how data moves between your computer’s main chip and graphics chip. By keeping the "heavy lifting" local, it skips the need for massive cloud infrastructure.

While it uses a smaller 27-billion parameter model compared to the massive AI giants, Wen claims it’s still punching above its weight. He says it performs similarly to older high-end models like Claude Opus 4.6, handling daily tasks like shopping research and math homework without breaking a sweat. Plus, it encrypts the keys to your accounts, so even if the AI has permission to help you book stuff, your credentials stay locked down.

The business model

Here’s the plot twist: it’s free, and it’s not running ads. Instead of selling your data, Underdog plans to make money like a fintech app. With backing from Stripe’s Patrick Collison, the app will take a small percentage from transactions you make through the AI assistant, like an interchange fee. It’s a total vibe check on the industry, basically saying, "We don’t need to sell you out to turn a profit."

Conway Research, the team behind Underdog, has some major industry names in its corner, including Andreessen Horowitz, Khosla Ventures, and Vercel’s Guillermo Rauch.

Why it matters

AI is increasingly becoming the main character in our digital lives. If your assistant has access to your medical and financial secrets, do you really want that data floating around someone else's server? Underdog is testing the idea that we can have high-powered AI without the surveillance trade-off. If it works, it might just force the bigger players to get their act together on privacy.