Sepal AI

Proximal, founded in fall 2025 in San Francisco, describes itself as a data research lab that builds complex, long-horizon reinforcement learning environments and evaluation data for frontier AI labs and enterprises. It started with coding-agent training data and is expanding into drug design, chip design and legacy software modernization; it also released the open benchmark FrontierSWE.

Micro1, founded in 2022 in Palo Alto, California, helps AI companies source and manage human contractors for data labeling and model training.

AfterQuery, founded in 2024 in San Francisco, USA, is an applied research company that provides expert datasets and reinforcement learning training environments for frontier AI models.

Founded in 2018 and headquartered in San Francisco, Labelbox is an AI data and agent infrastructure company offering Horizon (RL environments for frontier labs), Recursion managed agents for enterprises, and the Alignerr expert network for labeling, evaluation and human feedback.

Mechanize, Inc. (San Francisco, 2025) was founded by former Epoch AI researchers Tamay Besiroglu, Matthew Barnett and Ege Erdil. It builds simulated work environments and graders for frontier coding agents, used for RL training and evaluation. In Aug–Sep 2026 Google reportedly struck a talent-plus-nonexclusive-license deal with it; the company remains independent under CEO Guive Assadi.

Fleet (fleetai.com), founded in 2024 and based in New York, builds high-fidelity reinforcement-learning environments that replicate enterprise software such as Salesforce and Excel plus browser/desktop workflows, so frontier AI labs and enterprises can train and evaluate computer-use agents. Founder and CEO Nicolai Ouporov was a founding engineer at Respell (acquired by Salesforce).