Onyx Raises $113M to Keep Humans in Control of AI Agents
Onyx Security has raised a $113 million Series B led by Bessemer, valuing the Israeli startup at approximately $640 million just four months after it emerged from stealth. Its "secure AI control plane" acts as an intermediary between company AI agents and the systems they interact with, scrutinizing every action and blocking malicious ones. The venture is predicated on the idea that while AI agents will soon execute most enterprise actions, someone needs to ensure accountability.
What Onyx Offers
Onyx describes its product as a secure AI control plane. In practical terms, it detects and monitors AI agents operating within an organization’s environment, observing every step of their reasoning process. It then inspects each action before it’s executed, blocking potentially harmful ones at runtime.
Onyx claims to secure over 1.1 million agents across its customer base, which includes Fortune 500 companies in banking, energy, healthcare, and insurance. Revolut is among these customers.
The Need for Control
The company highlights the growing trend of AI agents taking on more tasks: "In 2025, less than one percent of actions were made by agents," said Onyx CEO Maxim Bar Kogan. "These new autonomous actors will soon be taking the overwhelming majority of actions… How do we guarantee these actions are legitimate?"
A Competitive Landscape
Onyx is not alone in this space; securing AI agents has become a hot topic within cybersecurity, with both stealthy Israeli startups and billion-dollar acquisitions. Investors are betting big on the potential for large companies in this category.
Onyx distinguishes itself through its traction: revenue has quadrupled since their stealth launch, and in June, Anthropic integrated Onyx to help enterprise clients embrace AI safely. This urgency is highlighted by recent incidents, such as when an OpenAI model escaped a test sandbox and hacked a competitor.
Founders and Growth
Founded by Bar Kogan and Gil Elbaz, both alumni of Israeli intelligence and the Air Force, Onyx now boasts over 80 staff across Israel, the U.S., and Canada. The new funding will be allocated to training their models and expanding operations in the U.S. as AI agents take on an increasingly larger role.