Harmonic Security raises $50M to govern how employees use AI tools

Harmonic Security raises $50M to govern how employees use AI tools

Workplace artificial intelligence security startup Harmonic Security Inc. today announced it has raised $50 million in new funding to grow its platform for governing how employees use AI tools.

The company’s platform inspects anything an employee sends to an AI tool at work before it gets there. Custom small language models read each interaction in context, and a verdict comes back within milliseconds. Live credentials pasted into a chat window are one example of what the system is tuned to catch, according to Harmonic. A developer referencing a database schema should pass.

Those checks originally ran only in the browser, and over the past year Harmonic has extended them to desktop AI applications and agentic workflows. In Harmonic’s view, those tools are where problems such as employees signing in to AI services with personal accounts tend to start.

Co-founder and Chief Executive Alastair Paterson said “every board I talk to” now wants to know whether AI is delivering value, on top of how to reduce the risk of using it. Harmonic’s answer is a Usage Intelligence layer that runs on the same models. Leaders can see which AI use cases are paying off, down to individual employees who have worked out a faster way to get their jobs done.

Outside its own platform, Harmonic has been plugging into tools enterprises already use. Agent Builder, which Cisco Systems Inc. announced for its Cloud Control platform at Cisco Live in June, lists Harmonic among its ecosystem integrations. The connection runs over Model Context Protocol.

A second integration, with the Claude Compliance API from Anthropic PBC, pulls activity logs from Anthropic-hosted Claude Platform deployments into Harmonic. Organizations on Claude Enterprise also get the content of conversations.

More than 100 companies are customers, some of them among the largest enterprises in the world, and Harmonic said millions of their employees are covered. Climb Global Solutions Inc. and Distology Ltd. have signed on as distribution partners. Staff numbers have passed 90 across the U.S. and the U.K., and the new money will pay for more engineering and go-to-market hires on both sides of the Atlantic.

That cash comes from an oversubscribed Series B round led by Crosspoint Capital Partners LP, and existing investors also took part. Before this, the company’s most recent raise was the $17.5 million Series A that Next47 led in October 2024.

Security “has too often slowed the adoption of new technology,” according to Zach Sivertson, a managing director at Crosspoint. Organizations taking up AI should not have to give up control to move quickly, he said, adding that Harmonic gives leaders the visibility to roll AI out sooner.

Paterson said the company has “real momentum” and that the round lets it build faster as the AI market keeps changing. Investors have now put $76 million into Harmonic.

Image: Harmonic Security