Just four months after its $35 million Series A round, Onyx raises in a $113 million Series B round to bring its valuation to $640. Onyx Security is Taming Autonomous AI in the EnterpriseArtificial intelligence is moving beyond basic chatbots to fully autonomous agents. In 2025, AI agents handled less than one percent of digital tasks in most organizations. The startup uses proprietary security models to track each step of an AI agent’s reasoning process. Onyx is used by Fortune 500 companies in banking, technology, insurance, and energy today for AI security.