Onyx Security (onyx.security), a New York and Tel Aviv-based provider of a secure AI control plane, has raised $113 million in Series B funding led by Bessemer Venture Partners. The platform gives security, governance, and infrastructure teams unified visibility, security controls, and governance over every AI agent, model, and interaction. The capital will support expansion of the control plane as AI agents take on more consequential work.
Bessemer Positions Onyx as Next Generational Security Bet
The timing comes amid rapid enterprise adoption of autonomous AI agents. Onyx's approach — a unified supervisory layer spanning observability, security, governance, orchestration, and ROI measurement — addresses gaps left by point solutions that focus narrowly on discovery or identity.
Enterprises Race to Deploy Agents Without Controls
Onyx customer data indicates 80% of enterprises expose sensitive data through agents and 93% run agents with excessive permissions. Traditional cybersecurity tools built for human-managed devices cannot govern non-deterministic agent behavior at machine speed. The platform monitors every stage of agent reasoning and can block, correct, or escalate actions before damage occurs.
Control Plane Combines Five Layers With Autonomous Remediation
Onyx built a single platform that discovers shadow AI, enforces runtime safeguards against prompt injection and memory poisoning, applies natural-language policy controls, routes LLM calls intelligently, and tracks adoption ROI. A proprietary Guardian Agent autonomously identifies risks and remediates issues across thousands of agents. The system trains its own models to understand AI reasoning in real time rather than relying on off-the-shelf LLMs.
"The internet created Palo Alto Networks. The endpoint created CrowdStrike. The cloud created Wiz. AI agents are the next technological revolution that will create a generational security company. This is why we're backing Onyx Security." — Bessemer Venture Partners
Top-Tier Syndicate Validates Category Leadership
Bessemer Venture Partners led the round at a ~$640 million valuation, with participation from Cyberstarts, TCV, Conviction, FirstMark, Vintage, QuantumLight, and G Squared. The syndicate's depth signals conviction that AI agent security will become one of cybersecurity's largest markets. Total funding now stands at $153 million.
Agentic AI Security Market Accelerates
The cybersecurity agentic AI market is projected to grow from $2.43 billion in 2026 to $9.63 billion by 2031 at a 31.71% CAGR per Mordor Intelligence. Regulatory pressure from the EU AI Act and frameworks such as NIST and MITRE is driving demand for unified control layers. Onyx has secured 1.1 million agents and analyzed 66.2 million sessions in real time across Fortune 500 deployments.
Revenue Quadruples in Four Months Post-Launch
Onyx emerged from stealth in March 2026 with $40 million in funding. Revenue has quadrupled since then while the company added integrations with Anthropic, OpenAI, Microsoft, Google, and AWS. It was named a Representative Vendor in Gartner's 2026 Market Guide for Guardian Agents four months after launch.