Meta launched its Muse Spark Open model on October 15, 2026, to challenge Chinese AI developers. This powerful tool handles complex coding and multi-step reasoning tasks. Meta said, "Muse Spark Open is the most powerful open-weight model ever released by a U.S. company." Developers can now run it on local hardware.

Meta has introduced a new open-weight artificial intelligence (AI) model for complex coding, multi-step reasoning and autonomous tasks, called Muse Spark Open. Launched on October 15, 2026, the model will serve as a way to reinforce Meta's standing in the open-weight AI industry, where Chinese AI developers like Alibaba's Moonshot AI and Z.ai have made progress. According to Meta, Muse Spark Open is the most powerful open-weight model ever released by a U.S. company.

The model has 816 billion total parameters, with 42 billion active parameters, and supports a context window of one million tokens. According to Meta’s official announcement, developers can download its model weights, customise its capabilities and run it on supported hardware. It's also been optimised for Apple's M5 Ultra-powered Mac Studio systems and lets you use the model on the local machine rather than all the time in the cloud.

Meta Muse Spark Open targets coding and AI agents

According to Meta, Muse Spark Open is designed to serve long jobs, complex software development, and multi-step reasoning. The capabilities are targeted at developers creating AI agents that can manage workflows with minimal human interaction.

According to the official blog post, the model is compatible with multiple inference engines, such as SGLang, vLLM, TensorRT-LLM, Hugging Face Transformers, Apple MLX and llama.cpp. The model can also be customised by the developer using the PyTorch framework.

Meta has added customisable, auto-tunable Helion GPU kernels to SGLang. The company claims that these will provide kernel-level performance boosts from 1.03x to 3.95x on Nvidia and AMD GPUs and a 3% end-to-end performance boost on AMD MI350.

Apple M5 Ultra enables local AI model deployment

One of the key features of Muse Spark Open is its optimisation for Apple’s M5 Ultra chip. According to Meta, two Mac Studio systems can be used together to power the model in Apple's MLX framework.

Meta states that each of the M5 Ultra Mac Studios can be configured with up to 512GB of unified memory with two systems, which will accommodate the model's weights across a maximum unified memory capacity of 1TB. This configuration may open up advanced AI development to those looking to utilise their own hardware to run models.

Meta is also said to have performed tests with local AI workflows, such as software development and video editing. These entailed editing an open-source Mastodon client called Ice Cubes and editing clips in DaVinci Resolve that were appropriate for vertical videos.

Where to download Meta Muse Spark Open

Muse Spark Open is available via API platforms such as Baseten, Fireworks AI, Groq, Modal, Nebius, OpenRouter and Together AI. Developers can access the model weights from Amazon SageMaker AI, Google Cloud Model Garden, Hugging Face and Microsoft Foundry Models.

Meta highlights safety measures

Muse Spark Open was added to extra safety training, as open-weight models can be modified and deployed on their own, said Meta. The model passed the company's release criteria derived from its Meta Superintelligence Scaling Framework, the company said.

The launch follows Meta’s recent efforts to expand its AI capabilities and compete more directly with closed-model developers such as OpenAI and Anthropic. With Muse Spark Open, Meta is aiming to provide developers with more flexibility and to compete with the existing giants in the open-weight AI market.