The Series A was led by Kleiner Perkins, and the Seed was led by Sequoia. Other participating investors included Redpoint Ventures, Theory Ventures, Vine Ventures, CRV, A*, and Abstract Ventures, in addition to angel investors, including John Hennessy, chairman of Alphabet Inc., Lip-Bu Tan, CEO of Intel, and Tri Dao, Chief Scientist at Together AI.

Sail Research is the infrastructure company purpose-built for long-horizon AI agents. Sail's platform combines two core components: an inference stack rebuilt from the ground up for throughput and efficiency, delivering up to 10x lower cost per token; and Sailboxes, a stateful sandbox environment designed to run for days rather than seconds. Together, they give teams the economics and scale to build agents that are maximally ambitious. Sail is backed by Kleiner Perkins, Sequoia, Redpoint Ventures, Theory Ventures, Vine Ventures, CRV, A*, and Abstract Ventures.