❯ Meta ships Muse Spark 1.3 at unchanged pricing, and Zuckerberg says open weights are coming soon

launch and pricePer Axios, Meta rolled out Muse Spark 1.3 in Muse Code and the Meta Model API, saying it significantly improves coding and agentic performance at the same price as Spark 1.2. Zuckerberg then said Meta’s Watermelon model and Muse Spark open weights are “coming soon,” describing the release as frontier performance almost too cheap to meter.

benchmarks and efficiencyPer the company and third-party evaluations, there are two sets of numbers. On capability: 88.8 on Terminal-Bench 2.1, matching GPT-5.6, and a third-party reading of 75.4% on DeepSWE 1.1, placing it ahead of GPT-5.6 Sol and Fable 5. The efficiency side is more interesting — against 1.2 it makes 20% fewer tool calls and uses 25% fewer tokens. Per Artificial Analysis, the limited-preview max variant scores 62 on the Intelligence Index, behind only Claude, and 68 on the Coding Agent Index, second overall. Note that the max variant is partner-only with no announced pricing; what is publicly available is a different tier.

holding price is the pointPer those same figures, a generational gain at flat pricing, combined with fewer tool calls and fewer tokens, means unit cost per task is falling. Engineering teams that select on cost per task feel this first: the same job now takes roughly a quarter fewer calls and a quarter less generated text. The open-weights promise points elsewhere — after GLM-5.3 moved to a restrictive license, a genuine Meta open-weights release would pry the open camp back open.

▪ SIGNALMatching frontier performance while cutting tool calls by a fifth, what Meta is selling is cost per task, not a leaderboard position.