Meta and Apple Bring Muse Spark Open to Mac Studio with 816 Billion Parameters

Meta announced the release of Muse Spark Open, an open-weight artificial intelligence model designed for coding and agentic work.

The model has 816 billion total parameters, including 42 billion active parameters, and a 1 million-token context window. Meta says it is suited to extended tasks, multi-step reasoning and software engineering.

Muse Spark Open runs across two Mac Studios

Meta worked with Apple to tune the model for two M5 Ultra Mac Studios with 512GB of memory each, using the latest MLX framework. The company describes the setup as a system with one terabyte of unified memory.

Meta says the M5 Ultra’s integrated GPU can use up to 512GB of unified memory in each Mac Studio, while the chip’s memory bandwidth reaches 1.2TB/s. That allows the two machines to hold the full model and read the portion required for each token.

512GB Mac Studio has not launched

Apple has not yet released the 512GB Mac Studio; it is expected later in October 2026. No price was provided, but the 256GB version already costs more than $10,000.

Muse Spark Open is available through the Baseten, Fireworks AI, Groq, Modal, Nebius, OpenRouter and Together AI API platforms. Its weights can be downloaded through Amazon SageMaker AI, Google Cloud Model Garden, Hugging Face and Microsoft Foundry Models, with a license permitting limited commercial use.

Meta CEO Mark Zuckerberg thanked Apple CEO John Ternus for the collaboration. Ternus posted about the partnership on October 15, 2026, while Meta AI chief Alexandr Wang told Axios that he was pleased the companies were working together.