Onyx Security raises $113M to control AI agents in enterprise, signaling where smart money is flowing

Onyx Security, a two-year-old startup with offices in Tel Aviv and New York, closed a $113 million Series B round on July 29. The round was led by Bessemer Venture Partners with participation from Cyberstarts, TCV, and others. The company’s valuation now sits at roughly $640 million. Onyx built what it calls an “AI control plane,” essentially a supervisory layer that discovers, monitors, and remediates risks created by AI agents operating across an organization. The centerpiece is something called the “Guardian Agent,” a supervisory component that watches other agents in real time and intervenes when they start doing things they shouldn’t. The platform currently secures more than 1.1 million agents and covers 1.8 million employees. It has analyzed 66.2 million sessions to date. Onyx only emerged from stealth mode in March 2026. In the four months since launch, the company’s revenue quadrupled. The company previously raised $40 million in March 2026, split between a $35 million Series A led by Conviction and a $5 million seed round from Cyberstarts. Total funding now exceeds $153 million. Onyx itself has no crypto or blockchain component. Co-founder Maxim Bar Kogan, the CEO, brings ...