We're open-sourcing Muse Spark Open!

First reported Oct 15, 2026, 17:10 UTC

Source reports

We're open-sourcing Muse Spark Open! This is an important release which is the most capable US open-weight model yet. 🇺🇸 - 816B parameters (42B active) - 1M token context window - Built for coding and long-horizon agents - Runs locally on two Apple M5 Ultra Mac Studios More… — @mattdeitke (X), Oct 15, 2026, 17:10 UTC

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