Changelog

Shipping in the open.

Every release of the Muse Code CLI and Meta’s Muse models, as it lands.

muse-spark-1.3Sep 2, 2026MODEL

Muse Spark 1.3 becomes Muse Code’s model

NEWReplaces Muse Spark 1.2 in Muse Code; same-day release on the Meta Model API as muse-spark-1.3 and muse-spark-1.3-contributor

IMPROVEDAbout 20% fewer tool calls and 25% fewer tokens than 1.2 on the same coding work

IMPROVEDAsks clarifying questions and flags when it is stuck instead of guessing

NEWPrices unchanged: $1.25 / $4.25 per 1M tokens on Standard, $0.10 / $0.20 on Contributor

NEWMax reasoning configuration in limited partner preview while safety testing finishes

muse codeAug 31, 2026GA

NEWMonthly plans: Everyday Usage ($5), High Usage ($15, 3× usage), Power Usage ($50, 10× usage); pay-as-you-go stays

NEWInter-session messaging: sessions on the same machine warn and answer each other over a local socket

NEWWorkflows: orchestrate teams of subagents across stages, monitored live in /workflows

NEWRewind: press Esc twice to roll the conversation back to a safe point from the event log

NEWMuse Code SDK in developer preview: TypeScript, built on the local Muse Session Protocol

muse-glimmerAug 10, 2026OPEN

NEWOpen-weight 30B agentic model distilled from Muse Spark, released under Apache 2.0

NEWRuns locally on a single consumer GPU (about 20 GB quantized); weights on Hugging Face, Ollama, and LM Studio

NEWA separate model: Meta has not documented it as a Muse Code backend

muse code betaAug 5, 2026BETA

NEWMuse Code beta for macOS and Linux — one-command install, browser auth at dev.meta.ai

NEWPersistent async background agents — active all session, not spawned per task

NEWAgent fan-out: sub-agents work in parallel in isolated git worktrees

NEWAppend-only local event log — replay-exact, restart-safe after crashes

NEWBuilt-in /plan, /grill, and /goal commands

NEWZero-data-retention requests now accepted via Meta sales

muse-spark-1.2Aug 5, 2026MODEL

NEWCo-trained with the Muse Code harness — rejection-sampled agent trajectories, goal conditioning, context compaction

IMPROVEDOptimized for multi-file refactors, long debugging sessions, and tasks that run past a single prompt

IMPROVEDKernel case study: 1,000+ tool calls sustained over 24 hours

NEWContributor and standard variants; expanded global access to the public preview

muse-spark-1.1Earlier in 2026

NEWMeta Model API opens: OpenAI-SDK-compatible endpoint at api.meta.ai/v1

NEW1,048,576-token context window

NEWModel API cookbook: API fundamentals, agent patterns, and end-to-end use cases