**Meta's Muse Spark series, a line of multimodal large language models optimized for agentic coding and tool use from Meta Superintelligence Labs, saw Muse Spark 1.3 launch on September 2, 2026, with gains in long-horizon tasks, fewer tool calls, and better usability.** The October 15 open-weights release of Muse Spark Open (an 816B/42B MoE model with 1M context, based on the 1.3 base) fulfilled a key roadmap item, while the October 12 debut of Muse Wonder as a stronger frontier successor redirected attention away from incremental Spark updates. With no official previews, API hints, or timelines for a 1.4+ version as of October 17, and historical cadence pointing to roughly monthly iterations that have now paused, trader consensus on Polymarket reflects low implied probability for any 1.4+ release by October 31. Upcoming catalysts include Meta's next earnings or AI announcements that could clarify whether Spark continues as a distinct line or merges into broader efforts.