Thinking Machines Lab is an AI research company founded in February 2025 by Mira Murati, the former chief technology officer of OpenAI, following her departure from that company in late 2024. The company assembled a founding team of several senior OpenAI researchers and engineers who left around the same time, and positioned itself as building AI systems that are more customizable, transparent, and collaborative with human users than existing chat-first products.
Founding and funding
Murati left OpenAI in September 2024 without publicly stating her next plans, and Thinking Machines Lab emerged months later with a founding team that included former OpenAI researchers such as John Schulman, who joined after a brief stint at Anthropic. The company raised a seed round reported at roughly $2 billion in mid-2025, one of the largest seed rounds in the history of the technology industry, at a valuation reported around $10 billion, reflecting investor appetite for teams with deep frontier-lab experience even before a product existed. The round drew participation from major venture firms and technology companies eager for exposure to a team seen as capable of building at the frontier alongside established labs like OpenAI, Anthropic, and Google DeepMind.
Tinker and product direction
In 2025 Thinking Machines Lab released Tinker, a developer-facing API and toolkit aimed at making Fine-tuning and customization of open-weight language models more accessible to researchers and smaller engineering teams, a departure from the closed, monolithic-assistant approach of ChatGPT-style products. The company framed Tinker as addressing a gap it argued the industry had underserved: infrastructure for people who want to adapt and control models directly rather than only consume them through a chat interface, a positioning that echoed some of the customization work in the Open-weights models ecosystem around models like Llama and Qwen. Murati and colleagues also published research and commentary emphasizing multi-human collaboration with AI systems, in contrast to the single-user chat paradigm popularized by ChatGPT.
Significance
Thinking Machines Lab's rapid, richly funded launch was widely read as part of a broader pattern of senior researchers leaving established labs to start new, well-capitalized ventures, alongside Ilya Sutskever's Safe Superintelligence Inc. and other 2024-2025 spinouts. Commentators noted the unusual dynamic of investors funding a company at multibillion-dollar valuations based primarily on team pedigree rather than a demonstrated product, a pattern some linked to broader concerns about an AI investment bubble.