Rein Security
Category: AI in Cybersecurity
Israeli runtime security platform that protects the AI agents enterprises build, giving visibility, governance and real-time guardrails over agent actions. Rein Security was founded in 2024. The company is led by Matan Bar-Efrat. Based in Tel Aviv, Israel. Team size: 11-50. Total funding raised: $35M. Latest round: Series A. Key investors include Glilot Capital, Sienna Venture Capital, Corner Ventures, Atlacle, RNP Capital Advisors, Ofer Ben-Noon (angel), Amir Jerbi (angel), Yoav Alon (angel).
- Founded
- 2024
- Headquarters
- Tel Aviv, Israel
- Team size
- 11-50
- Total funding
- $35M
Value proposition
Secures enterprise AI agents at runtime. Its patented code-native sidecar traces every agent action to the line of code and the business outcome, holds each agent to its defined role, and blocks harmful actions before they execute. It does this without routing data through a gateway or proxy.
Products and solutions
Enterprise Agent Security Platform covering agent discovery and inventory (agents, MCPs, apps), full execution tracing, dynamic action-level guardrails, agent posture and vulnerability management, AI agent supply-chain security, and automated fix generation. Also covers runtime AppSec use cases (API security, SCA reachability). Its Agent Breakers research team does vulnerability research.
Unique value
In-process, runtime visibility into what agents actually do, rather than only prompts or traffic. Execution data stays inside the customer's cloud with no gateway or proxy.
Target customer
Enterprise CISOs, AppSec and security teams in financial services, healthcare, SaaS, data, retail and energy that deploy custom or homegrown AI agents in production.
Industries served
Financial services, insurance, healthcare, SaaS, data/information services, retail, energy
Technology advantage
Patented runtime sidecar technology that sees the agent's application-layer execution (service calls, tool invocations, resources, identities). The founders have deep offensive and vulnerability-research backgrounds from Unit 8200, Check Point and Elbit. The Agent Breakers research team presented at Black Hat USA 2026.
How they differentiate
Focuses on agents built internally by enterprises and operates inside the customer's cloud at the application layer. Gateway or MCP-proxy approaches only see traffic crossing a control point; Rein ties agent actions to code paths and business outcomes and does not reroute data.
Main competitors
Zenity, Prompt Security (SentinelOne), Protect AI / Prisma AIRS (Palo Alto Networks), Sweet Security
Key partnerships
Named to TechCrunch Startup Battlefield 200, recognized by Omdia for AI security innovation.
Notable customers
Lemonade, Dun & Bradstreet
Major milestones
2024: founded. Jan 2026: emerged from stealth with an $8M seed round led by Glilot Capital. 2026: launched the Enterprise Agent Security Platform. Aug 2026: Agent Breakers presented the compromise of a top-5 US retailer's AI shopping agent at Black Hat USA. Named to TechCrunch Startup Battlefield 200. Oct 2026: $25M Series A, bringing total funding to $35M.
Growth metrics
Revenue up 8x and customers up 5x since the January 2026 launch. Secures thousands of AI agents executing millions of actions. Headcount grew from about 23 (Jan 2026) to 31 (Oct 2026).
Market positioning
Early-stage but fast-growing specialist in runtime security for enterprise AI agents. It pivoted from runtime AppSec into agentic AI security, one of roughly 40 vendors racing in this category.
Geographic focus
Israel (R&D) and the United States (New York go-to-market); global enterprise customers
Patents and IP
Patented runtime 'sidecar' technology, per the company and press.
About Matan Bar-Efrat
Ex-Cyberbit European Sales Manager and Regional Manager for the Netherlands; ex-Unit 8200 officer; Tel Aviv University.
Latest news about Rein Security
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Official website: https://reinsec.io