Thinking Machines Lab

Thinking Machines Lab is a San Francisco-based AI research and product company founded by Mira Murati, OpenAI's former chief technology officer, and publicly unveiled on February 18, 2025. The company states its mission is to make AI systems "more widely understood, customizable, and generally capable," and has emphasized publishing research and technical notes rather than operating as a closed lab. Co-founders and early team members came largely from OpenAI, including chief scientist John Schulman (an OpenAI co-founder) and, at launch, Barret Zoph and Luke Metz — both of whom later left the company. Thinking Machines closed a $2 billion seed round in July 2025 led by Andreessen Horowitz at a $12 billion post-money valuation, with Nvidia, Accel, ServiceNow, Cisco, AMD and Jane Street also participating — one of the largest first institutional rounds in Silicon Valley history. The company's first product, Tinker, launched October 1, 2025, is an API that lets developers fine-tune open-weight language models (including Meta's Llama and DeepSeek families) via supervised or reinforcement learning without managing the underlying distributed training infrastructure themselves. In January 2026, co-founders Barret Zoph and Luke Metz departed, along with researcher Sam Schoenholz, to rejoin OpenAI — a departure Wired described as not amicable, and which removed Zoph from his CTO role. In April 2026, Thinking Machines signed a multibillion-dollar, non-exclusive compute deal with Google Cloud (running on Nvidia GB300 infrastructure) to support Tinker's reinforcement-learning workloads. As of September 2026, the company was reported to be in discussions to raise new capital at a valuation of roughly $40 billion, with Accel considered a possible lead; an earlier round of talks in late 2025 reportedly explored a valuation as high as $50-60 billion but did not result in a closed round. Neither the $40 billion nor the earlier $50-60 billion figure reflects a completed financing and is not recorded as a funding round below.