Sigil Wen, a Thiel Fellow, has launched an invite-only beta of Underdog, an AI assistant designed with a strong emphasis on user privacy. The system operates entirely on the user's device, ensuring that personal data remains on their Macs and Windows PCs. Versions for Linux, iPhone, and Android are planned for future release.
Underdog incorporates security features such as encrypting keys for authorised email and other accounts. Wen developed Husky, an inference engine designed to run AI models quickly by moving less data between the computer's main and graphics chips.
The AI assistant uses a 27-billion parameter reasoning model, fine-tuned from Qwen3.8 27B. Wen states this model performs comparably to Claude Opus 4.6 in some benchmarks, which was considered top performance six months ago, making it suitable for everyday tasks like shopping research or answering math questions.
Underdog's business model is initially free and will not be ad-supported. Instead, it plans to take a small percentage of payment transactions made by the AI assistant using Stripe's secure payment rails. This approach aims to avoid collecting user data for sale or model training, a practice common among other AI assistant providers.
Conway Research, the startup behind Underdog, is backed by investors including Andreessen Horowitz, Khosla Ventures, and Stripe co-founder Patrick Collison.