Meta has released Muse Spark Open, an open-weight model designed for coding, agentic work, and multi-step reasoning. The natively multimodal system has 816 billion total parameters, with 42 billion active, and supports a 1 million-token context window.
The model can run locally across two Apple M5 Ultra Mac Studios using MLX. Each machine can provide up to 512 GB of unified memory, allowing the pair to hold the full model.
Meta says it tested on-device workflows that included shipping iOS changes, completing builds, and controlling DaVinci Resolve to review and crop footage.
Muse Spark Open is also available through APIs from Baseten, Fireworks AI, Groq, Modal, Nebius, OpenRouter, and Together AI. You can download its weights from Amazon SageMaker AI, Google Cloud Model Garden, Hugging Face, and Microsoft Foundry Models. Meta is releasing them under the Muse Model License, which permits free use for many developers but includes limited commercial terms.
Sources and related context #
- Muse Spark Open model card and license : Supports: Meta's model card confirms the parameter counts, 1M-token context window and MLX deployment, and includes the model's commercial license conditions.