Rein Security

Rein Security sells a security platform for companies that run AI agents and AI applications in production. Its argument is that prompts and gateways show only part of what an agent does, so the platform sits at the runtime layer where agents act and records each database access and API call, linking who reached what and why.

The platform is deployed as a sidecar. The site describes four areas. Visibility gives an audit trail of agent actions with business context. Prevention learns a baseline for each agent and stops deviations as they happen without taking the agent offline. Posture covers code security, vulnerability management, compliance, supply chain security and governance for agents. Privacy is the claim that agent data never leaves the organisation, because no gateway or proxy is involved.

Rein says one deployment spreads across AI and non-AI environments and finds services on its own. The same execution context also supports application security work such as software composition analysis, static analysis and real-time API security.

Pages are written for security teams, with solution pages for finance, healthcare, and SaaS and retail agents. Customer quotes come from security leaders at Dun & Bradstreet, Lemonade and H&R Block. The site announces a 25 million dollar Series A and 35 million dollars raised in total.

Key facts

• Product: runtime security platform for AI agents, MCP tools and applications
• Deployment: sidecar at the runtime layer
• Also covers: SCA, SAST and API security
• Funding: 25 million dollar Series A, 35 million dollars in total
• Pricing: not published; demo on request