Meta has launched 'Muse Code,' a terminal-based coding agent now in beta, designed to handle full software engineering tasks across large repositories. Powered by Meta's Muse Spark coding model, the tool launches parallel sub-agents that work together within isolated worktrees, leaving developers' working copies untouched. Meta CEO Mark Zuckerberg cited internal testing in which the tool built six features for a game simultaneously without collisions. AI chief Alexander Wang positioned the tool as a cost-effective alternative to competitors such as OpenAI's Codex and Anthropic's Claude Code. As AI coding agents become increasingly central to software development workflows, Meta's entry signals that major AI labs are racing to differentiate themselves through cost and parallel processing capabilities rather than competing solely on raw model performance.