Key Info

Meta's Muse Spark Open, billed as the strongest open-weight model from a US lab, is now available on OpenRouter with day-0 support from Baseten, Fireworks AI, Nebius, and Together Compute.

Highlights

  • Built for agentic coding and long-horizon tasks, complex software engineering, and multi-step reasoning
  • 816B total / 42B active parameters
  • 1M token context window
  • Fully multimodal: image, video, audio, and PDF input
  • Pricing: $1.25 per million input tokens, $4.25 per million output tokens