Muse Spark Open
Muse Spark Open is Meta’s open-weight multimodal model for agentic coding and long-horizon tasks: an 816-billion-parameter Mixture-of-Experts model with 42B active parameters per token and a one-million-token context window.
Model
Muse Spark Open is Meta’s open-weight multimodal model for coding and agentic work, with 816B total parameters, 42B active per token, and a one-million-token context window. Its Mixture-of-Experts Transformer pairs the language model with a Perception Encoder and accepts text, image, and video inputs to generate text.
Muse Spark Open supports multi-step reasoning, coding agents, and end-to-end task completion, including sequential tool use, failure recovery, and extended multi-turn workflows. It can interpret screenshots, charts, documents, and video, and can also support synthetic data generation and evaluation of other models’ outputs. The model was trained on data from more than 100 languages.
Shared Endpoint
On a Shared Endpoint, you pay per token. The endpoint is OpenAI-compatible and already live: point your existing SDK at it and start sending requests.