Meta releases Muse Spark Open weights, reversing its closed course with conditions

Meta on Thursday released the weights of Muse Spark Open, which it calls the most capable US open-weight model to date. The company said the multimodal model has 816 billion total parameters (42 billion active) and a one-million-token context window, and is built for coding and agentic work. Meta said the weights can be downloaded from Hugging Face, Amazon SageMaker AI, Google Cloud, and Microsoft Foundry. It also said the model received extra safety post-training and met the thresholds of its internal risk framework.