HiddenLayer raised $100 million as it claims 10x ARR growth securing AI agents
The Austin-based Series B, led by Delta-v Capital with Microsoft's M12 and Morgan Stanley participating, funds a new 'Agent Harness Security' product aimed at AI coding agents at runtime -- the revenue-growth figure is HiddenLayer's own claim, not independently verified.
HiddenLayer announced a $100 million Series B on September 2, 2026, led by Delta-v Capital with participation from Ten Eleven Ventures, Morgan Stanley, Microsoft's M12, and Booz Allen Ventures, bringing the Austin-based company's total funding past $155 million. The company, founded in 2022, builds security tooling meant to cover the full lifecycle of AI systems -- discovery, supply-chain security, attack simulation, and runtime protection -- rather than a single point product.
What the new money funds
The round funds a specific new product, Agent Harness Security, extending HiddenLayer's runtime protection to secure AI coding agents specifically while they write, review, and ship code -- a response to the same category of risk this site has covered repeatedly this year: agents acting with real permissions inside real systems, where a runtime boundary either holds or it doesn't. Delta-v Capital partner Dan Williams framed the investment thesis around breadth: HiddenLayer, in his words, "built a platform from the ground up to secure AI across its full lifecycle."
The growth number is a company claim, not a fact
HiddenLayer's own release states its annual recurring revenue grew more than 10x over the past year, with more than 90% of that growth from new customers signed in the same period -- both figures reported directly by the company, with no independent auditor or third party cited behind them. CEO Chris Sestito's own framing to TechCrunch was blunter about why the platform generalizes across use cases: "Inference is still inference." That's worth stating plainly rather than repeating as settled fact: a 10x ARR claim from a private security vendor raising a round is exactly the kind of number that's true often enough to be worth taking seriously, and also exactly the kind of number a company has every incentive to round favorably. Treating a vendor's self-reported growth rate with the same skepticism this site applies to a vendor's self-reported benchmark numbers is the same discipline either way.