On October 15, Meta released Muse Spark Open, an 816-billion-parameter open-weight AI model designed for coding and other agent tasks. Meta worked with Apple to run the model locally across two Mac Studios, offering developers another way to use it beyond cloud services.
Muse Spark Open released
Meta describes Muse Spark Open as its most capable U.S. open-weight model to date. The model accepts text, images, video and audio, and has a context window of about 1 million tokens. It activates 42 billion parameters for each token, although serving it still requires loading the full model weights.
Meta made the model available through Hugging Face, cloud catalogs from Amazon, Google and Microsoft, and hosted providers including Baseten, Fireworks AI, Groq, Modal, Nebius, OpenRouter and Together AI. Meta listed those launch options in its announcement.
Apple hardware proves the point
To demonstrate local use, Meta and Apple used the MLX framework to run Muse Spark Open on two M5 Ultra Mac Studios. Each machine can provide up to 512 gigabytes of unified memory, giving the pair about 1 terabyte to hold the model. Meta tested the setup with coding and video-editing workflows that ran on the devices.
The collaboration is notable because Apple and Meta have spent years competing over privacy, advertising and consumer devices. Axios reported that the partnership shows how the AI race is changing relationships between technology rivals. It also gives developers an alternative to proprietary models and Nvidia-only infrastructure.
Open weights bring limits
Meta released the weights under its Muse Model License. The company says the terms allow many developers to use the model for free. However, companies offering it as a model-as-a-service product must notify Meta and enter a separate agreement when their aggregate gross revenue exceeds $20 million in a 12-month period.
The model also requires substantial hardware for local use. Meta’s documentation lists about 1.65 terabytes of weights for the full-precision version and about 537 gigabytes for a compressed version. Hosted services provide another way to use the model without supplying that hardware.
References
Axios. (2026, October 15). Apple and Meta bury the hatchet—for AI. https://www.axios.com/2026/10/15/apple-and-meta-bury-the-hatchet-for-ai
Meta. (2026, October 15). Build with Muse Spark Open. https://dev.meta.ai/resources/blog/build-with-muse-spark-open
Meta AI Research. (2026, October 15). Introducing Muse Spark Open, the most capable U.S. open-weight model to date. https://research.meta.ai/blog/muse-spark-open
Meta. (n.d.). Muse Spark Open. Meta Model API. https://dev.meta.ai/docs/muse-spark-open
Meta. (2026, October 15). Muse Model License. Hugging Face. https://huggingface.co/meta-models/Muse-Spark-Open-816B-A42B/blob/main/LICENSE.md