Artificial intelligence agent security startup AIR Security Inc. formally launched today with $50 million in funding to build what it calls an inline firewall for AI agents.

Founded earlier this year, AIR is going after a gap that has opened as coding agents spread through large enterprises. Those agents reach for third-party skills, plugins and Model Context Protocol servers on their own initiative. The security team rarely sees what got picked up. AIR’s software sits in that path and screens the instructions, tools and data heading into an agent’s context before the agent acts on any of it.

Discovery comes first. The platform maps the agents already running across endpoints, cloud accounts and software-as-a-service applications, then keeps re-checking the components those agents depend on. A skill that passed review in March can be rewritten in June by whoever maintains it. Untrusted tools and injected instructions are blocked at runtime, and AIR also runs a marketplace of add-ons it has already cleared.

Company researchers have put some numbers on the exposure. More than 17,800 public AI add-ons, accounting for 6.7 million installations, drew instructions from outside sources nobody had verified. The team also turned up AI skills impersonating Anthropic PBC and OpenAI Group PBC that could run arbitrary code once installed. Roughly 27% of the add-ons and skills AIR finds online get filtered out.

More than 20 companies use the platform and about a quarter of them are large enterprises, with the strongest demand so far coming from financial services and pharmaceutical firms, according to TechCrunch.

“Every enterprise has a firewall protecting its network,” Chief Executive Yair Saban said. “Now they need one protecting their AI agents.”

Saban started the company with Chief Technology Officer Niv Hoffman. Both spent years in Unit 8200, the Israeli military intelligence corps, doing offensive cybersecurity work, and about 40 people now work for them. Ryan Knisley signed on as chief strategy officer after holding the chief information security officer job at both The Walt Disney Co. and Costco Wholesale Corp.

The $50 million came in two rounds, both closed inside the company’s first six months. Sequoia Capital led the first at $10 million and Greenoaks Capital Partners led the $40 million that followed. Swish Ventures and Netz Capital also invested. Angel backers include Wiz Inc. co-founder Yinon Costica, Clay co-founder Varun Anand, Eon co-founder Ofir Ehrlich, Cognition President Zach Frankel and Anne Neuberger, the former White House deputy national security adviser for cyber and emerging technology.

Bogomil Balkansky, a partner at Sequoia Capital, told TechCrunch the problem AIR is addressing is “not a scanning problem” but one of continuous re-verification, since the components an agent uses keep changing underneath it. Greenoaks partner Patrick Backhouse made a related point in the funding announcement, saying agents work at runtime with skills, plugins, add-ons and MCP servers “from sources that no security team has reviewed.”

AIR, based in New York, will spend the new money on hiring researchers and building out sales in the U.S. and Europe.

Image: AIR Security