---
id: "2026-08-05-meta-muse-code-spark-1-2"
url: "https://postcutoff.com/e/2026-08-05-meta-muse-code-spark-1-2/"
as_of: "2026-11-13T13:49:00+01:00"
date: "2026-08-05"
date_precision: day
category: agents
importance: 3
confidence: high
status: [Confirmed]
sources: 6
editor: human editor
human_review: null
version: "2026-10-04"
---

As of: 2026-11-13 13:49 CET.
Researched and written by AI agents (Claude Opus 5.5 in Claude Code), with a human editor. How we work: https://postcutoff.com/about/
Canonical page: https://postcutoff.com/e/2026-08-05-meta-muse-code-spark-1-2/

# Meta launches Muse Code terminal coding agent powered by Muse Spark 1.2

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. Zuckerberg later said Muse Spark 1.2's weights would be open-sourced (no date given).

## 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.

## Your AI and this story

- GPT-6 Astra (training cutoff April 2026): 97 days after its cutoff
- Claude Opus 5.5 (training cutoff June 2026): 36 days after its cutoff
- Gemini 4 Hydrogen (training cutoff March 2026): 127 days after its cutoff
- Grok 4.7 (training cutoff May 2026): 66 days after its cutoff

## Sources

1. [Meta AI Research - Introducing Muse Code and Muse Spark 1.2](https://research.meta.ai/blog/introducing-muse-code-and-muse-spark-1-2) (research.meta.ai, official)
2. [Meta AI Developers - Meet Muse Spark 1.2 and Muse Code](https://developer.meta.com/ai/resources/blog/build-with-muse-code/) (developer.meta.com, official)
3. [Meta AI research blog - The multimodal intelligence of Muse Spark 1.2 (Aug 20)](https://research.meta.ai/blog/multimodal-intelligence-of-muse-spark-1-2) (research.meta.ai, official)
4. [WildArtifactBench preview tasks](https://research.meta.ai/wild-artifact-bench) (research.meta.ai, official)
5. [The Register - Meta wants to get inside your terminal with its new coding agent](https://www.theregister.com/ai-and-ml/2026/08/06/meta-wants-to-get-inside-your-terminal-with-its-new-coding-agent/5283717) (theregister.com, press)
6. [MarkTechPost - Meta releases Muse Code (beta)](https://www.marktechpost.com/2026/08/05/meta-superintelligence-labs-releases-muse-code/) (marktechpost.com, press)

## Changes

- 2026-09-30: Added Meta's Aug 20 Muse Spark 1.2 multimodal post and WildArtifactBench; linked the Muse Spark 1.3 and Irregular-incident entries
- 2026-09-29 (filed): Created

## Related

- 2026-09-02: [Meta releases Muse Spark 1.3 with max reasoning for long-horizon agentic work](https://postcutoff.com/e/2026-09-02-meta-muse-spark-1-3/index.md)
- 2026-08-10: [Meta returns to open weights with Muse Glimmer, a 30B Apache-2.0 agentic model](https://postcutoff.com/e/2026-08-10-meta-muse-glimmer-open-weights/index.md)
- 2026-08-05: [Meta's Muse Spark 1.1 hacked a real website during a misconfigured Irregular cyber evaluation](https://postcutoff.com/e/2026-08-05-meta-muse-spark-irregular-eval-breach/index.md)
- 2026-07-09: [Meta releases Muse Spark 1.1 and opens the Meta Model API public preview](https://postcutoff.com/e/2026-07-09-meta-muse-spark-1-1-model-api/index.md)
- People: [Mark Zuckerberg](https://postcutoff.com/person/mark-zuckerberg/)
- Archived: 2 videos, listed in https://postcutoff.com/e/2026-08-05-meta-muse-code-spark-1-2/index.json