Meta ships Muse Spark Open, its answer to China’s best open-weight models

Meta on Thursday launched Muse Spark Open, a new 816B open model (with 42B active parameters) that the company argues is the “most capable US open-weight model to date.”

The new model is available through the APIs of Baseten, Fireworks AI, Groq, Modal, Nebius, OpenRouter, and Together AI.

And since it’s an open model, you can also download the weights from Amazon SageMaker AI, Google Cloud Model Garden, Hugging Face, and Microsoft’s Foundry Model Catalog.

Open Weights, semi-open license Overall, Muse Spark Open, which features the industry-standard 1 million token window, looks to be an extremely capable model that, depending on the benchmark, is on par with or beats some of the best Chinese models.