Meta Opens 816B Parameter Model Muse Spark Open to Developers, Trained on NVIDIA Blackwell Ultra

Meta released Muse Spark Open on October 15, 2026, an 816-billion parameter mixture-of-experts model designed for coding agents and agentic workflows, available as open weights via Hugging Face. The model activates 42.7 billion parameters per token through sparse routing, reducing computational overhead while maintaining strong capability across long and complex tasks.