Muse Spark Open
The gist
Meta released open weights for Muse Spark Open, an 816B-parameter multimodal model, on Oct 15, 2026.
It runs locally on two M5 Ultra Mac Studios.
How it unfolded
- Oct 15, 2026Meta released the weights for Muse Spark Open, a natively multimodal model with 816B total parameters (42B active) and a 1M-token context window, calling it the most capable US open-weight model to date.
- Oct 15, 2026The model became available via API platforms including Baseten, Fireworks AI, Groq, Modal, Nebius, OpenRouter and Together AI, with weights downloadable on Amazon SageMaker AI, Google Cloud Model Garden, Hugging Face, and Microsoft Foundry Models.
- Oct 15, 2026Apple published MLX research showing Muse Spark Open (816B) in NVFP4 precision generating over 36 tokens per second on a cluster of four Mac Studios, and NVIDIA published a blog on scaling agentic coding with the model on GB300 NVL72.