Claude Fable 5

{
  "id": "anthropic/claude-fable-5",
  "name": "Claude Fable 5",
  "description": "Claude model for creative writing, analysis, and controlled agent workflows",
  "family": "claude-fable",
  "last_updated": "2026-06-09",
  "knowledge": "2026-01-31",
  "attachment": true,
  "reasoning": true,
  "tool_call": true,
  "temperature": false,
  "modalities": {
    "input": [
      "text",
      "image",
      "pdf"
    ],
    "output": [
      "text"
    ]
  },
  "limit": {
    "context": 1000000,
    "output": 128000
  },
  "benchmarks": [
    {
      "name": "SWE-Bench Pro",
      "score": 80.3,
      "source": "https://www.anthropic.com/news/claude-fable-5-mythos-5",
      "metric": "resolve rate",
      "date": "2026-06-09"
    },
    {
      "name": "SWE-Bench Verified",
      "score": 95,
      "source": "https://benchlm.ai/benchmarks/sweVerified",
      "metric": "resolved"
    },
    {
      "name": "Terminal-Bench",
      "score": 88,
      "source": "https://www.anthropic.com/news/claude-fable-5-mythos-5",
      "metric": "success rate",
      "version": "2.1",
      "date": "2026-06-09"
    },
    {
      "name": "Humanity's Last Exam",
      "score": 59,
      "source": "https://www.anthropic.com/news/claude-fable-5-mythos-5",
      "metric": "accuracy",
      "variant": "no tools",
      "date": "2026-06-09"
    },
    {
      "name": "Humanity's Last Exam",
      "score": 64.5,
      "source": "https://www.anthropic.com/news/claude-fable-5-mythos-5",
      "metric": "accuracy",
      "variant": "with tools",
      "date": "2026-06-09"
    },
    {
      "name": "OSWorld-Verified",
      "score": 85,
      "source": "https://www.anthropic.com/news/claude-fable-5-mythos-5",
      "metric": "success rate",
      "date": "2026-06-09"
    },
    {
      "name": "FrontierCode",
      "score": 29.3,
      "source": "https://www.anthropic.com/news/claude-fable-5-mythos-5",
      "metric": "pass rate",
      "variant": "high effort",
      "dataset": "Diamond",
      "date": "2026-06-09"
    },
    {
      "name": "GDPval-AA",
      "score": 1932,
      "source": "https://www.anthropic.com/news/claude-fable-5-mythos-5",
      "metric": "Elo",
      "date": "2026-06-09"
    },
    {
      "name": "AutomationBench",
      "score": 17.4,
      "source": "https://www.anthropic.com/news/claude-fable-5-mythos-5",
      "metric": "success rate",
      "date": "2026-06-09"
    }
  ],
  "release_date": "2026-06-09",
  "open_weights": false
}