Open Thoughts is a project led by Bespoke Labs and the DataComp community, aimed at curating high-quality open-source reasoning datasets for training advanced small models. The project brings together researchers and engineers from various universities and research institutions, including Stanford University, the University of California, Berkeley, and the University of Washington, dedicated to promoting the development of reasoning models through high-quality datasets. The project is established in response to the growing demand for applications of reasoning models in fields such as mathematics and code reasoning, where high-quality datasets are critical for improving model performance. Currently free to access, the project primarily targets researchers, developers, and professionals interested in reasoning models, with its open-source datasets and tools serving as a significant resource for advancing AI education and research.