Meta's Muse Spark is here - and it's closed source

This article was published on April 8, 2026 In short: Meta has released Muse Spark, the first model from Meta Superintelligence Labs, the unit it assembled under Alexandr Wang after spending $14.3 billion to acquire a stake in Scale AI. Rebuilt from scratch over nine months, the model is natively multimodal, introduces a “Contemplating” reasoning mode that runs sub-agents in parallel, and is now powering Meta AI across the company’s platforms. In a break from Meta’s Llama heritage, it is closed source. The model’s arrival closes a chapter that began in June 2025, when Mark Zuckerberg announced Meta Superintelligence Labs and installed Wang as the company’s first-ever chief AI officer. The mandate was explicit: catch up with OpenAI, Anthropic, and Google, and do so with a team and infrastructure rebuilt specifically for the task. Nine months later, that team has something to show for it. “Nine months ago we rebuilt our AI stack from scratch,” Wang wrote on X on Wednesday. “New infrastructure, new architecture, new data pipelines. Muse Spark is the result of that work, and now it powers Meta AI.” The statement is a direct acknowledgement of how deep the rebuild went: not a fine-tuned