Meta unveils open-weight Muse Spark Open model

Meta announced its open-weight AI model Muse Spark Open on October 15, 2026. Focused on coding and agent tasks, the model supports text, image, video and audio inputs.

The MoE model contains 816 billion parameters in total. It activates 42 billion parameters per token, with a context window of up to 1 million tokens.

Local use requires specialized hardware

Running Muse Spark Open locally on a Mac does not mean an ordinary Mac setup. It requires a specialized setup with two Apple M5 Ultra Mac Studios and MLX infrastructure.

Open weights, not unrestricted open source

The model’s weights are available under the Muse Model License. Accessible weights do not mean the model is open-source software granting unrestricted usage rights.

For details, see Meta’s official announcement and Webrazzi’s RSS report.