Bespoke Labs Raises $31.75M Series A for AI Agent Training

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Bespoke Labs, an applied AI research company based in Santa Clara, California, has raised $31.75 million in a Series A round led by Wing VC. Mayfield and The House Fund joined the round, along with employees at major technology firms, bringing the startup’s total funding to $40 million.

Founded in 2024 by Mahesh Sathiamoorthy and Alex Dimakis, Bespoke Labs builds reinforcement learning environments, data curation systems and infrastructure for training and evaluating AI agents. The team is a core contributor to Terminal-Bench, a widely cited benchmark for agentic capability, and is behind OpenThoughts, an open reasoning dataset downloaded more than 500,000 times.

The company will put the new capital toward enhancing its reinforcement learning platform and funding more data research for AI development.