Meta unveils Muse Spark Open with 1M context, 42B active
According to AI at Meta on X, Meta released Muse Spark Open, a US open-weight model for coding and agentic work with 816B total and 42B active parameters, a 1M-token context window, and native multimodal support across text, image, video, and audio.
SourceAnalysis
Meta AI released Muse Spark Open on October 15, 2026, describing it as the most capable US open-weight model available at the time.
The model targets coding and agentic applications, with strengths in long-horizon tasks, complex software engineering, and multi-step reasoning according to the announcement. Key specifications include 816B total parameters with 42B active parameters, a 1M token context window, and native multimodality supporting text, image, video, and audio inputs.
AI at Meta
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