Infisical Raises $40M Series B at $600M Valuation to Secure AI Agents

Infisical has raised $40 million in Series B funding at a $600 million valuation to solve a security problem that enterprise AI adoption has created: how software agents can work inside critical systems without ever holding the credentials that unlock them.

Elad Gil led the round. He also invested in Infisical's Series A. Gradient and Y Combinator participated. The San Francisco company plans to spend the money on product development, larger engineering and go-to-market teams, and security infrastructure built specifically for AI agents.

The bet rests on an existing business. Infisical says it serves more than 1,300 customers and 300,000 developers, and secures 10 billion secrets daily. Its core open-source project has drawn more than 30,000 GitHub stars. Named customers include Airbus, Volkswagen, Hugging Face, OpenRouter, Lucid, First American Financial Corporation, Wise, and Clay.

Those numbers describe the wider platform, not Agent Vault, its newest product. The product page still carries a "preview" label. The financing therefore supports two things at once: an established secrets-management business and a push into unproven agent access infrastructure.

How does Agent Vault actually work?

Agents that investigate incidents, review code, or automate workflows often need access to repositories, cloud services, and business applications. Placing credentials directly in the agent's environment creates one more route for sensitive data to leak into logs, reach model providers, or land in the hands of an attacker using prompt injection.

Agent Vault brokers access through a forward proxy. The agent sends a request toward an approved service; the proxy attaches the real credential on the way out. Depending on configuration, it can attach or replace an authorization header, or substitute a credential for a placeholder. Infisical says the underlying secret stays out of the agent's environment, filesystem, and model context. The approach works with HTTP clients that honor the standard HTTPS_PROXY configuration, so it can fit into existing agent runtimes.

In plain terms, this changes where trust sits. An agent can ask an authorized service to do work without ever reading the API key that authenticates the request.

Infisical's documentation describes access bundles as lists of services an agent can use during a session, including APIs and MCP servers. Sessions provide time-bound access. Proxies intercept outbound requests and attach real credentials, and session logs keep an encrypted record of what was requested.

What credential isolation cannot fix?

Here the company's own framing meets a hard limit. Isolation alone cannot stop an agent from misusing access it has already been granted. An agent with permission to modify a system can still make an unwanted modification using that permitted access. Teams must define which services and actions a job actually requires, alongside credential controls.

The relevant security question becomes twofold: whether an agent can obtain a secret, and what it can accomplish without ever seeing one. Infisical did not disclose how many customers currently use Agent Vault.

CEO Vlad Matsiiako put the company's pitch in employee terms. "You wouldn't give an employee unrestricted access to every system in your company, and AI agents shouldn't be any different," Matsiiako said. "Agents need access to company systems to do their jobs, but giving them actual passwords and API keys is a major security risk. We let agents get their job done safely without ever having those credentials in their hands."

What does the $600 million valuation buy?

Matsiiako said Infisical will keep investing in secrets management, certificate management, and privileged access management while increasing its focus on Agent Vault. The company is hiring for more than 100 positions across engineering, sales, marketing, product, design, and other teams.

Lead investor Elad Gil framed the opportunity as decade-scale. "AI agents are becoming a new class of users inside every enterprise, and securing their access will be one of the biggest cybersecurity challenges of the next decade," Gil said. "Vlad and co-founders Maidul and Tony recognized early that AI agents would create an entirely new set of security challenges, and they've built Infisical into a platform that I believe can become essential infrastructure for the AI era."

The wider enterprise shift is already visible in new identity and credential controls for agents. As agents take on work across business systems, security teams need ways to connect delegated authority with observable actions, and to revoke access when that authority ends. Infisical's proposition is concrete: delegate the work, keep the keys under security infrastructure built to manage them. Whether a preview-stage product can carry a $600 million valuation is the question this round now has the cash to answer.