See, Control, and Audit Every Enterprise Agent Action.

Rein Security was built to address a gap the broader cybersecurity industry was ignoring: enterprise agents. While most vendors focused on productivity chatbots and developer coding assistants, a new class of agents had quietly entered production — moving money, accessing sensitive systems, making customer-facing decisions, and living on the public internet. Rein's founders, both with deep enterprise security backgrounds, concluded that none of the existing proxy, gateway, or eBPF-based approaches could secure agents that needed to be understood from the inside, and so built a sidecar-based platform that lives alongside the agent with full execution context.

The Rein platform organizes around four capabilities: discovery, coverage, protection, and privacy. Discovery maps every agent action back to its actual business outcome rather than inspecting raw prompts in isolation. Coverage extends across inventory, posture, vulnerability management, compliance, supply chain security, and governance from a single deployment. Protection enforces granular, dynamic guardrails on individual agent actions in real time, stopping harmful behavior before it reaches a business-impacting outcome. The privacy pillar is designed so that no agentic data leaves the organization, positioning Rein as viable for regulated industries with strict data residency requirements.

Rein's distinguishing approach is execution context: security decisions are grounded in what an agent is actually doing and why it matters to the business, not just what text it generated. The platform deploys once and automatically extends across both AI and non-AI environments, covering AppSec use cases such as SCA, SAST, and real-time API security alongside agentic workflows. Rein is positioned for enterprises in sectors like finance, healthcare, and SaaS where agents are operating on high-value systems, and where security teams need coverage that keeps pace with agent adoption without forcing workflow tradeoffs.