Harmonic Security Raises $50M to Guard Employee AI Use

Harmonic Security, a startup founded in 2023 by Alastair Paterson and Bryan Woolgar‑O’Neil, announced a $50 million Series B round that brings its total funding to $76 million. The company offers a platform that inspects every interaction employees send to AI tools—whether on the web, on desktop apps, or in agentic workflows—using custom small language models that classify tasks and provide real‑time controls. The platform also exposes risks such as personal‑account use and sensitive data exposure, and delivers a Usage Intelligence layer that shows which AI use cases add value to employee workflows.

Crosspoint Capital Partners led the oversubscribed round, with existing investors also participating. Harmonic has already signed more than 100 enterprise customers, covering millions of employees, and has formed distribution partnerships with Climb Global Solutions and Distology Ltd. The platform now plugs into tools already in use at enterprises, including Cisco’s Agent Builder and Anthropic’s Claude Compliance API, allowing the company to pull activity logs from Claude deployments into its own dashboard. The new money will be used to expand engineering and go‑to‑market teams in the US and the UK, helping the firm grow faster as the AI market evolves.