Infisical Raises $40 Million at $600 Million to Keep API Keys Out of the Hands of Rogue AI Agents

Infisical, the open-source secrets management platform, has raised a $40 million Series B at a $600 million valuation, led by Elad Gil with continued participation from Gradient Ventures and Y Combinator, according to Forbes. The round's thesis is less about storing secrets for people and more about withholding them from machines: as companies put autonomous agents into production, the credentials those agents carry have become the softest spot in enterprise security.

The problem Infisical is attacking showed up twice this month alone. Bank of America warned customers that anyone who shares their banking password with an AI assistant owns the losses that follow. LiteLLM, an open-source gateway with 23 million downloads, shipped a compromised release that contained a credential stealer. And AWS disclosed a set of agent-platform flaws, scored a perfect 10.0, that exposed credentials across cloud environments. An agent that holds live API keys is a single prompt injection away from handing them over.

The company's answer, launched alongside the round, is Agent Vault, an access-brokering proxy. Instead of storing sensitive API tokens, passwords or encryption keys in the agent's environment, the agent routes outgoing requests through an HTTPS forward proxy that attaches the appropriate authorization headers on the fly. Administrators configure time-bound access bundles defining which APIs and MCP servers an agent may interact with, and every session is logged for audit — without secrets ever entering the model's context window or landing on disk.

The traction figures are company-reported: Infisical says it secures more than 10 billion secrets daily across 1,300 enterprise customers and 300,000 developers, with customers including Airbus, Volkswagen, Hugging Face, OpenRouter and Wise, on top of an open-source platform that has crossed 30,000 GitHub stars. The company plans to hire more than 100 people across engineering and commercial roles.

What is interesting about the round is where it places a Y Combinator-era secrets manager in the market. Credential brokering for non-human identities is becoming a security category of its own — adjacent to the agent-identity and permission-governance space, but anchored in the unglamorous plumbing of key storage. If agents are going to act on behalf of companies, someone has to hold the keys and decide, request by request, whether the agent gets to use them. Infisical is betting that the answer is a proxy that never shows the agent the key at all.