Meta has released Muse Code, a new terminal coding agent currently available in beta that can accomplish complete software engineering tasks across large repositories, including planning changes, writing code, and validating results. The tool can be installed with a single command and is powered by Meta's previously released coding model, Muse Spark.
Muse Code handles large projects by launching its own agents that work simultaneously in parallel. When a job is large enough, it fans out to separate sub-agents working in parallel in isolated worktrees, ensuring the user's working copy is never touched. In testing, Meta had the tool build six features for a game simultaneously with no collisions.
The release positions Meta more competitively against AI lab peers like OpenAI with its coding agent Codex and Anthropic with Claude Code. Meta's AI chief Alexandr Wang told the Wall Street Journal the tool could be an incredibly good option for many workflows and use cases, especially from a cost perspective.