Muse Spark

What it is

Muse Spark is the proprietary model family from Meta Superintelligence Labs, first released on 8 April 2026 at meta.ai and in the Meta AI app. Meta describes it as “a natively multimodal reasoning model with support for tool-use, visual chain of thought, and multi-agent orchestration,” with particular strength in visual STEM reasoning, entity recognition and localisation.

Muse Spark is available through Meta AI, Muse Code and the Meta Model API. Meta’s current model documentation lists the supported versions and their context windows. The newer Muse Wonder family launched on 12 October 2026 with separate access and pricing.

The versions

Muse Spark (8 April 2026). The launch model, available in Meta’s own products with a private API preview for selected users.

Muse Spark 1.1 (9 July 2026). The version that came with the first paid developer API in Meta’s history, at $1.25 per million input tokens and $4.25 per million output, with $20 in free credits and United States availability at launch. It has a one-million-token context window, supports computer use across desktop, browser and mobile surfaces, and delegates work to parallel subagents while acting as the lead agent itself. Meta positioned it against GPT-5.5 and Claude Opus 4.8, claiming first place on MCP Atlas, JobBench, Humanity’s Last Exam and Finance Agent V2. Replit, Cline and Box were named as early partners.

Muse Spark 1.3 (2 September 2026). An efficiency release: Meta reports about 20 per cent fewer tool calls and about 25 per cent fewer tokens than 1.2 on coding tasks, so the same work costs less and finishes sooner. On the Artificial Analysis Intelligence Index, rebased to v4.3 on 7 September 2026, it scores 48 at maximum effort. At our 2 October 2026 read that puts it level with GPT-6 Sol, behind Claude Opus 5.5 on 58, Claude Sonnet 5.5 on 56, Claude Fable 5.1, GPT-6 Astra and Gemini 4 Argon on 53, GPT-6.1 Sol on 52 and Claude Opus 5 on 51. Announced on Meta’s own research blog.

Muse Spark 1.2 (5 August 2026). A coding-focused update, released alongside Muse Code and co-trained with that harness on rejection-sampled trajectories from it. Meta scaled training compute on coding tasks and widened the range of training environments, targeting whole-repository generation, long end-to-end projects and auto-research. It is available in Muse Code and in the Meta Model API with what Meta calls expanded global access. Meta’s current documentation lists a 1,048,576-token context window for the Spark versions, including 1.2.

Contemplating mode

The headline feature of the original release is Contemplating mode, which Meta says “orchestrates multiple agents that reason in parallel” rather than running a single chain of thought. In that mode Meta reports 58 per cent on Humanity’s Last Exam and 38 per cent on the FrontierScience Research benchmark. As with any launch benchmark, these are the lab’s own figures and are best read alongside independent testing, but the design choice is the point: Muse Spark is built to spread a hard problem across several reasoning agents at once.

What it costs

The following prices and rate limits cover Spark 1.2, checked against Meta’s pricing documentation on 13 October 2026.

Prices are per million tokens. The contributor tier trades heavily discounted tokens for permission to use prompts and completions to train future Meta models; the standard tier states that prompts and completions are not used for training. Token throughput is 4 million a minute on standard against 3 million on contributor.

Built on a rebuilt stack

Meta frames Muse Spark as the product of a rebuilt pretraining stack rather than a larger version of an old one. It says the new approach reaches its capabilities “with over an order of magnitude less compute” than its earlier Llama 4 Maverick model. The company has not published a parameter count for any Muse Spark version.

Why it stands out

Muse Spark combines reasoning, image understanding and tool use in one family. The appropriate version depends on the task, permitted data use and available rate limits. Compare it with the newer Muse Wonder and other large language models.

The latest related release

Meta released Muse Spark Open weights on 15 October 2026. The downloadable model has its own Muse Model License and deployment requirements.