# Muse Spark Open

id: ent_muse-spark-open  
kind: product  
timeline: /timelines/muse-spark-open.md  
page: /record/muse-spark-open  
same_as: https://asof.is/record/muse-spark-open (how to cite the id: /identifiers.md)  

816B (42B active) open-weights MoE model by Meta

## Fact pages

One page per fact: the current value with its sources, then every dated value and what replaced what. Fetch any of them as markdown.

- [Muse Spark Open release date](/record/muse-spark-open/model_release.md)
- [Muse Spark Open context window](/record/muse-spark-open/context_window.md)

## Current state

What the record asserts: claims that held, valid by their sources or primary-sourced at confidence 0.7 or more. Unverified, disputed, retracted and review-marked claims are listed below, labelled, not here.

- [Muse Spark Open](/record/muse-spark-open.md) | context_window | 1M-token | valid 2026-10-15 to present | conf 0.95 | valid | [clm_086E8B7FB0F7](/claim/clm_086E8B7FB0F7.md)
  sources: https://research.meta.ai/blog/muse-spark-open

## All claims

One claim per line, newest first. Superseded claims stay visible.

- [Muse Spark Open](/record/muse-spark-open.md) | context_window | 1M-token | valid 2026-10-15 to present | conf 0.95 | valid | [clm_086E8B7FB0F7](/claim/clm_086E8B7FB0F7.md)
  sources: https://research.meta.ai/blog/muse-spark-open

## Posts and Hugging Face repos (1)

Dated items from the entity's own feeds, and the days its Hugging Face repositories were created, newest first.

- [Muse Spark Open](/record/muse-spark-open.md) | model_release | Muse Spark Open | valid 2026-10-15 to present | conf 0.95 | valid | [clm_D58FC12544C0](/claim/clm_D58FC12544C0.md)
  sources: https://research.meta.ai/blog/muse-spark-open

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AsOf is a temporal fact ledger: a structured, dated, sourced record of what is true and what changed, built for AI retrieval.