Harvey raises $550M, buys Guardrails AI same week

Harvey closed a $550 million round at a $15.6 billion valuation. The company also acquired Guardrails AI the same week, per Bloomberg. Lightspeed and Diffusion co-led the round, with Sapphire and Whale Rock joining in.

The valuation almost doubled from $11 billion in March. Annual recurring revenue has passed $350-400 million, and Harvey now counts 80% of Am Law 100 firms as customers, meaning the top tier of US corporate law is already paying for it.

The money isn't going toward renting someone else's frontier model. Harvey says the capital is earmarked for proprietary models rather than wrapping frontier ones, and the Guardrails AI purchase points at why. A company built on top of other people's models is now buying the layer that checks and constrains model output before it reaches a lawyer's desk.

That's the harder bet. Any vertical AI company can pay for API access. Fewer can afford to own the validation tooling that sits between a model's output and a client-facing legal document, and fewer still have the revenue to justify building it in-house instead of licensing it.

Am Law 100 penetration at 80% means Harvey's growth ceiling in its core market is closer than the valuation implies. The proprietary model push and the guardrails purchase both read as a company preparing to compete on accuracy and control, not on being first to market. That was the easier pitch two years ago.