Harvey closes a $550M round and buys Guardrails AI

Harvey closed a $550 million funding round at a $15.5 billion valuation co-led by Lightspeed and Diffusion, then acquired Guardrails AI without disclosing terms; Guardrails’ founders and team join Harvey. The deal is Harvey’s fourth acquisition of 2026 and shifts a legal-AI scale story toward owning agent reliability. Builders comparing Harvey’s own-model economics should treat agent assurance as part of a vertical-model moat, not a bolt-on.