Meta has released the weights for Muse Spark Open, an open-weight AI model the company describes as the most capable of its kind from the United States so far. The model can run on a desktop setup, though the hardware requirement is substantial: two Mac Studios powered by Apple’s M5 Ultra chip.

Muse Spark Open has 816 billion total parameters, a one-million-token context window, and support for text, images, video, and audio. It is designed for coding and autonomous work that can span many steps, including complex software engineering and multi-step reasoning.

Muse Spark Open Model Specifications

Muse Spark Open uses 816 billion parameters in total, with 42 billion active at a time. Its one-million-token context window allows the model to retain and work with large amounts of information during a task.

The model supports several input types out of the box:

  • Text
  • Images
  • Video
  • Audio

Meta built Muse Spark Open for coding and agentic tasks. That focus includes longer-running work, challenging logic problems, and software tasks that require multiple stages rather than a single response.

Hardware Needed to Run Muse Spark Open Locally

Running Muse Spark Open on a desktop requires two Mac Studio systems using Apple’s M5 Ultra chip. The setup relies on Apple’s unified memory architecture.

Each M5 Ultra Mac Studio GPU can access up to 512GB of memory. By dividing the model across two systems, the pair can operate with a combined terabyte of memory. The setup also provides 1.2 TB/s of memory bandwidth.

That arrangement is what makes local operation of a model at this scale possible. It is still a costly desktop configuration, so it will not be a practical route for every user.

What Meta Tested With Muse Spark Open

Meta tested the two-Mac-Studio setup on real projects using Muse Code.

In one test, the model worked on Ice Cubes, an open-source Mastodon app. It addressed bugs, delivered new features, and handled the complete build process.

Meta also used the model with DaVinci Resolve. In that workflow, it reviewed clips frame by frame and cropped selected shots for vertical displays.

Ways to Access Muse Spark Open Without Two Mac Studios

You do not need the specified Mac Studio setup to try Muse Spark Open. The model is available through platforms including Groq and OpenRouter.

Developers can also download the model weights from Hugging Face.