Atlacle has invested in Rein Security and announced a new initiative to support stronger security in AI agent execution environments. As the first investment by Atlacle Fund I, it participated in the Series A round and outlined plans to expand collaboration in the Japanese market.
Atlacle Fund I announced that it had invested in the Series A round of Rein Security, Inc. This was Atlacle Fund I’s first investment and is described as a decision to invest in the company’s technology for providing security in AI agent execution environments.
Rein Security operates a platform that provides security for the runtime in which AI agents execute actions. Using a sidecar architecture, the platform provides functions for visualizing and controlling AI agent behavior and access destinations.
The company was established in 2024. Since launching its product in January 2026, it has grown sales 8x and its customer base 5x. It has reportedly been adopted across a wide range of industries, including finance, insurance, SaaS, data and retail.
Atlacle plans to expand collaboration with Japanese companies and support Rein Security’s global growth. It also emphasized the importance of Security, Permission, Governance, Auditability and Compliance in the Japanese market.