Thinking Machines Lab

Thinking Machines Lab Inc. is an American artificial intelligence (AI) startup founded by Mira Murati, the former chief technology officer of OpenAI. Their flagship model is Inkling, an open weights large language model. The company was founded in February 2025, and by July had completed an early-stage funding round led by Andreessen Horowitz, raising $2 billion at a valuation of $12 billion overall from investors such as Nvidia, AMD, Cisco, and Jane Street. The company is based in San Francisco and structured as a public benefit corporation. Inkling released under the Apache License on July 15, 2026, with 975 billion parameters; the company released Inkling Small, a distilled 276-billion parameter model with similar performance, the same month. The model was partially developed using Chinese open weights models DeepSeek-V3 for its foundation and Moonshot AI's Kimi K2.5 for post-training synthetic data. At the time, Inkling was considered the largest and most powerful open weights model released outside of China, exceeding Nvidia's Nemotron 3 Ultra. Thinking Machines launched Tinker, an API for fine-tuning open weights models, in October 2025. As of August 2026, Tinker supports open models families Inkling, Qwen, and Nemotron, and models DeepSeek-V3.1, GLM-5.3, Kimi K2.6, and gpt-oss.