{
  "site": "Agentic Weekly",
  "dataset": "Agentic Weekly model facts",
  "as_of": "2026-10-26",
  "license": {
    "name": "CC BY 4.0",
    "url": "https://creativecommons.org/licenses/by/4.0/"
  },
  "attribution": "Data: Agentic Weekly (https://theagenticweekly.com), CC BY 4.0",
  "page": "https://theagenticweekly.com/models",
  "evidence_labels": {
    "Reported": "Read from the cited vendor page on the as-of date; not run by us.",
    "Tested": "We ran it ourselves; scope is stated in tested_note. No model is Tested yet."
  },
  "model": {
    "slug": "muse-spark-open",
    "name": "Muse Spark Open",
    "vendor": "Meta",
    "family": "Muse",
    "category": "llm",
    "status": "generally-available",
    "groups": [
      "open-weights",
      "frontier"
    ],
    "short_answer": "Muse Spark Open is Meta's latest language model in our dataset, released Oct 15, 2026. Open weights (Muse Model License (limited commercial terms)). Meta's open-weights 816B-parameter mixture-of-experts model (42B active), released Oct 15, 2026 under the Muse Model License, which has limited commercial terms. Verified against vendor sources on Oct 26, 2026.",
    "summary": "Meta's open-weights 816B-parameter mixture-of-experts model (42B active), released Oct 15, 2026 under the Muse Model License, which has limited commercial terms.",
    "release_date": "2026-10-15",
    "latest_update": null,
    "api_id": null,
    "context_tokens": 1000000,
    "max_output_tokens": null,
    "input_modalities": [
      "text",
      "image",
      "video",
      "audio"
    ],
    "output_modalities": [
      "text"
    ],
    "parameters": {
      "total": "816B",
      "active": "42B",
      "architecture": "mixture-of-experts, 256 experts, 8 active"
    },
    "license": "Muse Model License (limited commercial terms)",
    "open_weights": true,
    "pricing": null,
    "evidence": "Reported",
    "tested_note": null,
    "last_verified": "2026-10-26",
    "is_stale": false,
    "facts": {
      "release_date": {
        "value": "2026-10-15",
        "source_url": "https://research.meta.ai/blog/muse-spark-open",
        "as_of": "2026-10-26",
        "evidence": "Reported"
      },
      "context_tokens": {
        "value": 1000000,
        "source_url": "https://research.meta.ai/blog/muse-spark-open",
        "as_of": "2026-10-26",
        "evidence": "Reported"
      },
      "input_modalities": {
        "value": [
          "text",
          "image",
          "video",
          "audio"
        ],
        "source_url": "https://research.meta.ai/blog/muse-spark-open",
        "as_of": "2026-10-26",
        "evidence": "Reported"
      },
      "output_modalities": {
        "value": [
          "text"
        ],
        "source_url": "https://research.meta.ai/blog/muse-spark-open",
        "as_of": "2026-10-26",
        "evidence": "Reported"
      },
      "parameters": {
        "value": {
          "total": "816B",
          "active": "42B",
          "architecture": "mixture-of-experts, 256 experts, 8 active"
        },
        "source_url": "https://huggingface.co/meta-models/Muse-Spark-Open-816B-A42B",
        "as_of": "2026-10-26",
        "evidence": "Reported"
      },
      "license": {
        "value": {
          "type": "open-weights-restricted",
          "name": "Muse Model License (limited commercial terms)",
          "openWeights": true
        },
        "source_url": "https://huggingface.co/meta-models/Muse-Spark-Open-816B-A42B",
        "as_of": "2026-10-26",
        "evidence": "Reported",
        "note": "Not an OSI-approved open-source license; read the terms before commercial use."
      }
    },
    "vendor_claims": [
      "Needs about 700 GB of VRAM for the NVFP4 checkpoint and about 2 TB for BF16, per Meta; it is not a laptop model."
    ],
    "notes": [
      "Meta lists hosted access at Baseten, Fireworks, Groq, Modal, Nebius, OpenRouter and Together; prices are set by those providers."
    ],
    "not_verified": [
      "Meta's own API price: not stated by Meta. Meta's proprietary Muse Spark 1.x models appear on public leaderboards but we did not verify their specifications; Muse Wonder is listed separately."
    ],
    "sources": [
      {
        "label": "Meta research blog",
        "url": "https://research.meta.ai/blog/muse-spark-open"
      },
      {
        "label": "Hugging Face model card",
        "url": "https://huggingface.co/meta-models/Muse-Spark-Open-816B-A42B"
      }
    ],
    "url": "https://theagenticweekly.com/models/muse-spark-open",
    "markdown": "https://theagenticweekly.com/models/muse-spark-open.md",
    "api": "https://theagenticweekly.com/api/models/muse-spark-open"
  }
}