Theorem wants to stop AI-written bugs before they ship — and just raised $6M to do it

As artificial intelligence reshapes software development, a small startup is betting that the industry's next big bottleneck won't be writing code — it will be trusting it.

Theorem, a San Francisco-based company that emerged from Y Combinator's Spring 2025 batch, announced Tuesday it has raised $6 million in seed funding to build automated tools that verify the correctness of AI-generated software. Khosla Ventures led the round, with participation from Y Combinator, e14, SAIF, Halcyon, and angel investors including Blake Borgesson, co-founder of Recursion Pharmaceuticals, and Arthur Breitman, co-founder of blockchain platform Tezos.

The investment arrives at a pivotal moment. AI coding assistants from companies like GitHub, Amazon, and Google now generate billions of lines of code annually. Enterprise adoption is accelerating. But the ability to verify that AI-written software actually works as intended has not kept pace — creating what Theorem's founders describe as a widening "oversight gap ...