{"type":"post","id":"muse-spark-open-on-fireworks-meta-s-open-316301","slug":"muse-spark-open-on-fireworks-meta-s-open-316301","title":"Muse Spark Open on Fireworks: Meta’s Open Weights Model, Available on US Serverless","description":"**Thesis:** A model’s open weights create options, but the serving route determines which teams can put those options into production.","retrieval_nugget":"**Thesis:** A model’s open weights create options, but the serving route determines which teams can put those options into production.","published_at":"2026-10-21","updated_at":"2026-10-21","record_date":"2026-10-21","date_kind":"published_at","topics":["open-models","inference"],"source_urls":["https://fireworks.ai/blog/meta-muse-spark-open"],"schema_version":"newruntime-agent-readable-v0.2","stable_id":"post:muse-spark-open-on-fireworks-meta-s-open-316301","status":"published","visuals":[],"editorial_provenance":{"schema_version":"newruntime-editorial-copy-v1","content_status":"source_grounded_final","final_copy_sha256":"sha256:cf0fb90f3593119537ba9f6da50e4839bc334e07b948ae50c8504bf57a0026c3","reviewed_at":"2026-10-21T08:05:08.924Z","source_evidence_count":1,"verified_claim_count":3,"site_analysis_schema_version":"newruntime-site-analysis-v1","site_object_kind":"field_note","observed_fact_count":3,"implication_count":2,"watch_condition_count":1,"related_record_count":0},"analysis":{"schema_version":"newruntime-site-analysis-v1","object_kind":"field_note","thesis":"A model’s open weights create options, but the serving route determines which teams can put those options into production.","observed_facts":[{"text":"Fireworks says Muse Spark Open is available on its serverless API using US-only capacity, with no US premium and Zero Data Retention by default.","source_urls":["https://fireworks.ai/blog/meta-muse-spark-open"]},{"text":"The source describes an 816-billion-parameter model with 42 billion active parameters per token and a one-million-token context window.","source_urls":["https://fireworks.ai/blog/meta-muse-spark-open"]},{"text":"Fireworks offers reserved throughput for production workloads and serverless LoRA training.","source_urls":["https://fireworks.ai/blog/meta-muse-spark-open"]}],"mechanism":"A distinct hosting route packages access to open weights with stated geographic capacity, data-retention defaults, and options for production throughput and model adaptation.","why_now":"Fireworks’ announcement adds a provider-specific serving option after earlier reports of the model’s availability on other platforms.","implications":["Teams can compare another hosting route against their geographic, data-handling, and workload requirements.","Reported benchmark results are not interchangeable because the announcement describes different evaluators and harnesses."],"evidence_boundary":"The evidence is Fireworks’ company announcement. Its performance figures are vendor-reported or benchmark-specific; the source says some third-party results were measured on Meta’s API release. It does not establish comparative performance on a reader’s workload or independently verify service terms.","watch_conditions":["Watch for independent, same-workload tests across providers and confirmation of current pricing and operational terms for reserved throughput and LoRA training."],"related_records":[],"new_branch_reason":"No prior New Runtime analytical record was supplied; this begins a distinct record on Fireworks’ serving route and its stated deployment terms for Muse Spark Open."},"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-open-on-fireworks-meta-s-open-316301/","markdown":"https://newruntime.com/posts/muse-spark-open-on-fireworks-meta-s-open-316301.md","json":"https://newruntime.com/posts/muse-spark-open-on-fireworks-meta-s-open-316301.json"},"related_shifts":["compute-backed-ai-contracts"],"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/inference/","url":"https://newruntime.com/topics/inference/","title":"Inference","reason":"Explore the inference topic hub.","media_type":"text/html","markdown_url":"https://newruntime.com/topics/inference.md","json_url":"https://newruntime.com/topics/inference.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":"/source-ledger.json","url":"https://newruntime.com/source-ledger.json","title":"Source Ledger","reason":"Inspect the public source evidence graph.","media_type":"application/json"}]}