Meta launches Muse Code terminal coding agent powered by Muse Spark 1.2
Confirmed
The takeaway
On 2026-08-05 Meta Superintelligence Labs launched Muse Code (beta), a terminal coding agent for long-horizon software engineering, powered by a new code-focused model, Muse Spark 1.2 - Meta’s answer to Claude Code, Codex CLI and Grok Build.
Status
- Claim
Confirmed
- Our reporting
- High confidence
- Importance
- 3 of 5
- Last verified
- 30 September 2026
Your AI and this story
- GPT-6 Astra97 days after its cutoff
- Claude Opus 5.536 days after its cutoff
- Gemini 4 Hydrogen127 days after its cutoff
- Grok 4.766 days after its cutoff
None of these four assistants can know about it. The closest, Claude Opus 5.5, stops 36 days before it.
Key facts
- Muse Code (beta) and Muse Spark 1.2 announced 2026-08-05
- Plans, implements and validates multi-file changes across large repos using persistent async sub-agents
- Local append-only event log of every model call, tool run, approval and edit - replay-exact and restart-safe
- Muse Spark 1.2 also available in the Meta Model API with expanded global access
- Meta demo: Muse Spark 1.2 optimized KDA and MLA kernels for NVIDIA Hopper GPUs over 1,000+ tool calls
- Reported pricing: $1.25/$4.25 per 1M tokens, or $0.10/$0.20 if Meta may train on your code (MindStudio/secondary)
- Reported: on 2026-08-10 Zuckerberg said Muse Spark 1.2 weights will be open-sourced, date TBD
- Aug 20 follow-up (Meta research blog): Muse Spark 1.2 multimodal results ‘ahead of the open-weights release’; tool use gives the largest multimodal gains; a Muse Spark variant plans tasks for a bimanual robot; Meta previewed WildArtifactBench (agent vs baseline, compared by human or agentic judges, win-rate/Elo) and released 10 of its tasks
What happened
MSL released Muse Code, a CLI coding agent built around a simple agent loop plus asynchronous background agents, with crash recovery via a local event log. It runs on Muse Spark 1.2, a coding-specialized model evaluated on Terminal-Bench 2.1, DeepSWE 1.1 and an internal Meta coding bench (charts only, no numbers in the post).
Why it matters
Every frontier lab now ships its own terminal coding agent; Muse Code is Meta’s entry into the most commercially valuable agent category of 2026.
Pricing and the open-sourcing pledge come from secondary sources and were not confirmed on the official post.
Sources
6 sources from 4 sites. Numbers match the chips in the text.
6 sources: 4 primary, 2 press
Primary
- Meta AI Research - Introducing Muse Code and Muse Spark 1.2research.meta.ai, official
- Meta AI Developers - Meet Muse Spark 1.2 and Muse Codedeveloper.meta.com, official
- Meta AI research blog - The multimodal intelligence of Muse Spark 1.2 (Aug 20)research.meta.ai, official
- WildArtifactBench preview tasksresearch.meta.ai, official
Press
- The Register - Meta wants to get inside your terminal with its new coding agenttheregister.com, press
- MarkTechPost - Meta releases Muse Code (beta)marktechpost.com, press
Changes
- Added Meta’s Aug 20 Muse Spark 1.2 multimodal post and WildArtifactBench; linked the Muse Spark 1.3 and Irregular-incident entries
- Filed
