Harmonic Security

Harmonic Security is a security software company focused on AI governance and control. Its website does not state where it is based or when it was founded. On 14 October 2026 it announced a $50 million Series B to secure the use of AI across the workforce.

What it does

The company describes its product as a control layer between a workforce and AI tools. It first shows how employees and software agents are using AI, then applies policy to that use as it happens. Three products are listed. Harmonic Explore gives visibility into AI usage. Harmonic Guide applies real-time controls in the browser and on the desktop. Harmonic Command handles governance for both people and agents. The aim is to let an organisation roll out AI broadly while keeping sensitive data from leaving through those tools.

Who it serves

The audience is security leaders at organisations that are adopting AI across their staff. Industries named on the site are technology, legal, insurance and healthcare. Logos under its customers heading include Advisor360, Anthropic, Apex, Cisco, HIG Capital, Hyperion, Monolithic Power Systems and NPL, although the page does not say whether each is a paying customer or a partner.

Key facts

Alastair Paterson is the chief executive and a co-founder. Crosspoint Capital Partners led the $50 million Series B, with existing investors taking part, and the company says total funding is now $76 million after a $17.5 million Series A in October 2024. It says it has more than 90 staff across the US and UK, with offices in San Francisco and London, and that it protects AI use for millions of employees at more than 100 companies, none of them named. Partners include Cisco Cloud Control's Agent Builder, a major AI vendor's compliance API, Climb and Distology. These figures are the company's own.