Poolside

Maker of the open-weight Laguna agentic coding models.

Poolside is a San Francisco-based foundation AI lab founded by former GitHub CTO Jason Warner and Eiso Kant, training models for software engineering from scratch with reinforcement learning from code execution feedback. Its open-weight Laguna family of mixture-of-experts models is built for agentic coding, pairing native reasoning with long-horizon tool use, from the flagship Laguna S to the compact Laguna XS that runs on a single GPU.