{"type":"post","id":"muse-spark-is-now-an-open-weights-model-67d449","slug":"muse-spark-is-now-an-open-weights-model-67d449","title":"Muse Spark Is Now an Open-Weights Model","description":"Meta has released Muse Spark Open’s weights on Hugging Face under the Muse Model License.","retrieval_nugget":"Meta has released Muse Spark Open’s weights on Hugging Face under the Muse Model License. The 816B-total, 42B-active model targets coding and agentic work, and the announcement pairs the release with inference-kernel and fine-tuning support. For builders, the change is a new self-hosting and adaptation option, not proof of production economics or independent model quality.","published_at":"2026-11-04","updated_at":"2026-11-07","record_date":"2026-11-04","date_kind":"published_at","topics":["open-models","models"],"entities":["Meta","Muse Spark Open","Muse Spark 1.3","SGLang","vLLM","Helion","TorchTitan"],"related_patterns":["harness-architecture-outlives-model-choice"],"novelty_label":"same_event","prior_refs":["https://newruntime.com/posts/meta-released-muse-spark-open-an-816b-total-5c27ac/"],"source_url":"https://pytorch.org/blog/muse-spark-open","source_urls":["https://pytorch.org/blog/muse-spark-open"],"schema_version":"newruntime-agent-readable-v0.2","stable_id":"post:muse-spark-is-now-an-open-weights-model-67d449","status":"published","visuals":[],"editor":{"role":"editor","name":"Andrey Reshetnikov","profile":"https://newruntime.com/owner-profile.md","profile_json":"https://newruntime.com/owner-profile.json","same_as":["https://www.linkedin.com/in/reshetnikov1/","https://t.me/lapetuse"]},"routes":{"html":"https://newruntime.com/posts/muse-spark-is-now-an-open-weights-model-67d449/","markdown":"https://newruntime.com/posts/muse-spark-is-now-an-open-weights-model-67d449.md","json":"https://newruntime.com/posts/muse-spark-is-now-an-open-weights-model-67d449.json"},"markdown_url":"https://newruntime.com/posts/muse-spark-is-now-an-open-weights-model-67d449.md","next_reads":[{"type":"topic","path":"/topics/open-models/","url":"https://newruntime.com/topics/open-models/","title":"Open Models","reason":"Explore the open-models topic hub.","media_type":"text/html","markdown_url":"https://newruntime.com/topics/open-models.md","json_url":"https://newruntime.com/topics/open-models.json"},{"type":"topic","path":"/topics/models/","url":"https://newruntime.com/topics/models/","title":"Models","reason":"Explore the models topic hub.","media_type":"text/html","markdown_url":"https://newruntime.com/topics/models.md","json_url":"https://newruntime.com/topics/models.json"},{"type":"collection","path":"/posts/","url":"https://newruntime.com/posts/","title":"Field Notes","reason":"Open the latest editorial analysis.","media_type":"text/html","json_url":"https://newruntime.com/posts.json"},{"type":"collection","path":"/sources/","url":"https://newruntime.com/sources/","title":"Sources","reason":"See the original sources this archive cites.","media_type":"text/html"}]}