Muse Spark 1.3

Muse Spark 1.3 was released September 2, 2026 by Meta's Superintelligence Labs under Chief AI Officer Alexandr Wang, the third point update to Meta's closed frontier line. It targets long-horizon agentic workflows — task tracking, multi-workflow threading in a single context, proactive gap identification — with Meta reporting roughly 25% fewer tokens and 20% fewer tool calls than 1.2 on comparable engineering tasks. It carries a 1M-token context window and is priced at $1.25/$4.25 per million tokens, with a contributor tier at $0.10/$0.20 for developers who let Meta use queries for training.

Meta's own benchmark card claims leads on coding and long-context rows and an Artificial Analysis Intelligence Index of 62. The honest caveats are structural: Muse Spark is closed weights — a promised open-weight release for 1.2 never materialized as of late September 2026 — the benchmark figures are Meta's and unreproduced, and the line represents Meta's deliberate move away from the open Llama strategy toward proprietary models. Wang has teased a larger successor codenamed Watermelon with no date.