{
  "api_version": "1",
  "updated": "2026-10-26",
  "latest_event": "2026-10-24",
  "rights": "© Frontier Log, all rights reserved.",
  "model": {
    "slug": "claude-fable-5-1",
    "name": "Claude Fable 5.1",
    "lab": "anthropic",
    "date": "2026-09-01",
    "source": "https://www.anthropic.com/claude-fable-and-mythos-5-1",
    "source_title": "Introducing Claude Fable 5.1 and Claude Mythos 5.1",
    "flagship": true,
    "event": "https://frontierlog.ai/event/2026-09-01-claude-fable-5-1-mythos-5-1",
    "releases": [],
    "variant_of": null,
    "made_by": "Anthropic",
    "url": "https://frontierlog.ai/model/claude-fable-5-1",
    "results": [
      {
        "id": "claude-fable-5-1:hle:no-tools:1",
        "model": "claude-fable-5-1",
        "model_name": "Claude Fable 5.1",
        "model_date": "2026-09-01",
        "event": "https://frontierlog.ai/event/2026-09-01-claude-fable-5-1-mythos-5-1",
        "benchmark": "hle",
        "benchmark_name": "Humanity's Last Exam",
        "setting": "no-tools",
        "setting_name": "No tools",
        "score": 60.9,
        "unit": "%",
        "printed": "60.9%",
        "reported_by": "anthropic",
        "run_by": null,
        "label": "Fable 5.1",
        "source": "https://www.anthropic.com/claude-fable-and-mythos-5-1",
        "source_title": "Introducing Claude Fable 5.1 and Claude Mythos 5.1",
        "source_date": "2026-09-01",
        "where": "benchmark table (HTML), row 'Multidisciplinary reasoning, Humanity's Last Exam', column 'Fable 5.1', 'no tools'",
        "own": true,
        "primary": true,
        "parallel": false,
        "notes": "",
        "caveat": "",
        "human_verified": true,
        "human_verified_on": "2026-10-17",
        "check": "human",
        "corroborated": true,
        "corroborated_on": "2026-10-19",
        "corroborated_by": [
          {
            "url": "https://www.anthropic.com/claude-fable-5-1-mythos-5-1-system-card",
            "name": "Claude Fable 5.1 and Mythos 5.1 card",
            "title": "Claude Fable 5.1 and Claude Mythos 5.1 System Card",
            "lab": "anthropic",
            "date": "2026-09-01",
            "printed": "60.9%",
            "where": "Figure 8.12.1.B HLE [no tools] test-time compute scaling (p.178), Claude Fable 5.1 \"max\" point label"
          },
          {
            "url": "https://www.anthropic.com/claude-opus-5-5-system-card",
            "name": "Claude Opus 5.5 card",
            "title": "Claude Opus 5.5 System Card",
            "lab": "anthropic",
            "date": "2026-09-22",
            "printed": "60.9",
            "where": "Table 8.1.A (p.174), row Humanity's Last Exam / No tools, column Claude Fable 5.1"
          }
        ],
        "source_capture": "https://frontierlog.ai/captures/f381a9ad69b68272.png"
      },
      {
        "id": "claude-fable-5-1:hle:with-tools:1",
        "model": "claude-fable-5-1",
        "model_name": "Claude Fable 5.1",
        "model_date": "2026-09-01",
        "event": "https://frontierlog.ai/event/2026-09-01-claude-fable-5-1-mythos-5-1",
        "benchmark": "hle",
        "benchmark_name": "Humanity's Last Exam",
        "setting": "with-tools",
        "setting_name": "With tools",
        "score": 65.0,
        "unit": "%",
        "printed": "65.0%",
        "reported_by": "anthropic",
        "run_by": null,
        "label": "Fable 5.1",
        "source": "https://www.anthropic.com/claude-fable-and-mythos-5-1",
        "source_title": "Introducing Claude Fable 5.1 and Claude Mythos 5.1",
        "source_date": "2026-09-01",
        "where": "benchmark table (HTML), row 'Multidisciplinary reasoning, Humanity's Last Exam', column 'Fable 5.1', 'with tools'",
        "own": true,
        "primary": true,
        "parallel": false,
        "notes": "",
        "caveat": "",
        "human_verified": true,
        "human_verified_on": "2026-10-17",
        "check": "human",
        "corroborated": true,
        "corroborated_on": "2026-10-19",
        "corroborated_by": [
          {
            "url": "https://www.anthropic.com/claude-fable-5-1-mythos-5-1-system-card",
            "name": "Claude Fable 5.1 and Mythos 5.1 card",
            "title": "Claude Fable 5.1 and Claude Mythos 5.1 System Card",
            "lab": "anthropic",
            "date": "2026-09-01",
            "printed": "65.0%",
            "where": "Figure 8.12.1.A HLE [with tools] reasoning-effort scaling (p.177), Claude Fable 5.1 \"max\" point label"
          },
          {
            "url": "https://openai.com/index/gpt-6-astra",
            "name": "GPT-6 Astra",
            "title": "GPT-6 Astra: A new generation of intelligence",
            "lab": "openai",
            "date": "2026-09-03",
            "printed": "65.0%",
            "where": "table 3 \"Humanity's Last Exam (w/ tools)\" row, \"Claude Fable 5.1\" column"
          }
        ],
        "source_capture": "https://frontierlog.ai/captures/f381a9ad69b68272.png"
      },
      {
        "id": "claude-fable-5-1:arc-agi-2:default:1",
        "model": "claude-fable-5-1",
        "model_name": "Claude Fable 5.1",
        "model_date": "2026-09-01",
        "event": "https://frontierlog.ai/event/2026-09-01-claude-fable-5-1-mythos-5-1",
        "benchmark": "arc-agi-2",
        "benchmark_name": "ARC-AGI-2",
        "setting": "default",
        "setting_name": "",
        "score": 90.0,
        "unit": "%",
        "printed": "90%",
        "reported_by": "anthropic",
        "run_by": null,
        "label": "Claude Fable 5.1",
        "source": "https://www.anthropic.com/claude-fable-5-1-mythos-5-1-system-card",
        "source_title": "Claude Fable 5.1 and Claude Mythos 5.1 System Card",
        "source_date": "2026-09-01",
        "where": "Section 8.16, Figure 8.16.B caption",
        "own": true,
        "primary": true,
        "parallel": false,
        "notes": "max effort; semi-private set; as reported by the ARC Prize Foundation",
        "caveat": "",
        "human_verified": true,
        "human_verified_on": "2026-10-17",
        "check": "human",
        "corroborated": true,
        "corroborated_on": "2026-10-19",
        "corroborated_by": [
          {
            "url": "https://openai.com/index/gpt-6-astra",
            "name": "GPT-6 Astra",
            "title": "GPT-6 Astra: A new generation of intelligence",
            "lab": "openai",
            "date": "2026-09-03",
            "printed": "90.0%",
            "where": "table 8 \"ARC-AGI-2\" row, \"Claude Fable 5.1\" column"
          }
        ],
        "source_capture": "https://frontierlog.ai/captures/03865a93633ebc0a.png"
      },
      {
        "id": "claude-fable-5-1:hle:with-tools:2",
        "model": "claude-fable-5-1",
        "model_name": "Claude Fable 5.1",
        "model_date": "2026-09-01",
        "event": "https://frontierlog.ai/event/2026-09-01-claude-fable-5-1-mythos-5-1",
        "benchmark": "hle",
        "benchmark_name": "Humanity's Last Exam",
        "setting": "with-tools",
        "setting_name": "With tools",
        "score": 65.6,
        "unit": "%",
        "printed": "65.6%",
        "reported_by": "anthropic",
        "run_by": null,
        "label": "Fable 5.1",
        "source": "https://www.anthropic.com/claude-opus-5-5",
        "source_title": "Introducing Claude Opus 5.5",
        "source_date": "2026-09-22",
        "where": "benchmark table, row 'Multidisciplinary reasoning, Humanity's Last Exam', column 'Fable 5.1', 'with tools'",
        "own": false,
        "primary": false,
        "parallel": false,
        "notes": "",
        "caveat": "",
        "human_verified": true,
        "human_verified_on": "2026-10-17",
        "check": "human",
        "corroborated": true,
        "corroborated_on": "2026-10-19",
        "corroborated_by": [
          {
            "url": "https://www.anthropic.com/claude-opus-5-5-system-card",
            "name": "Claude Opus 5.5 card",
            "title": "Claude Opus 5.5 System Card",
            "lab": "anthropic",
            "date": "2026-09-22",
            "printed": "65.6",
            "where": "Table 8.1.A (p.174), row Humanity's Last Exam / With tools, column Claude Fable 5.1"
          }
        ],
        "source_capture": "https://frontierlog.ai/captures/ca3ad55d7ec61f3c.png"
      },
      {
        "id": "claude-fable-5-1:swe-bench-pro:default:1",
        "model": "claude-fable-5-1",
        "model_name": "Claude Fable 5.1",
        "model_date": "2026-09-01",
        "event": "https://frontierlog.ai/event/2026-09-01-claude-fable-5-1-mythos-5-1",
        "benchmark": "swe-bench-pro",
        "benchmark_name": "SWE-bench Pro",
        "setting": "default",
        "setting_name": "",
        "score": 81.2,
        "unit": "%",
        "printed": "81.2%",
        "reported_by": "anthropic",
        "run_by": null,
        "label": "Fable 5.1",
        "source": "https://www.anthropic.com/claude-fable-5-1-mythos-5-1-system-card",
        "source_title": "Claude Fable 5.1 and Claude Mythos 5.1 System Card",
        "source_date": "2026-09-01",
        "where": "Section 8.2 'SWE-bench Pro, Multilingual, and Multimodal', first bullet",
        "own": true,
        "primary": true,
        "parallel": false,
        "notes": "average of 5 trials",
        "caveat": "The source doesn't say whether this is the public or the commercial set",
        "human_verified": true,
        "human_verified_on": "2026-10-17",
        "check": "human",
        "corroborated": true,
        "corroborated_on": "2026-10-19",
        "corroborated_by": [
          {
            "url": "https://www.anthropic.com/claude-opus-5-5-system-card",
            "name": "Claude Opus 5.5 card",
            "title": "Claude Opus 5.5 System Card",
            "lab": "anthropic",
            "date": "2026-09-22",
            "printed": "81.2",
            "where": "Table 8.1.A (p.174), row SWE-bench Pro, column Claude Fable 5.1"
          }
        ]
      },
      {
        "id": "claude-fable-5-1:deepswe-1-1:default:1",
        "model": "claude-fable-5-1",
        "model_name": "Claude Fable 5.1",
        "model_date": "2026-09-01",
        "event": "https://frontierlog.ai/event/2026-09-01-claude-fable-5-1-mythos-5-1",
        "benchmark": "deepswe-1-1",
        "benchmark_name": "DeepSWE v1.1",
        "setting": "default",
        "setting_name": "",
        "score": 67.4,
        "unit": "%",
        "printed": "67.4%",
        "reported_by": "anthropic",
        "run_by": null,
        "label": "Fable 5.1",
        "source": "https://www.anthropic.com/claude-fable-5-1-mythos-5-1-system-card",
        "source_title": "Claude Fable 5.1 and Claude Mythos 5.1 System Card",
        "source_date": "2026-09-01",
        "where": "Section 8.3 'DeepSWE v1.1', first paragraph",
        "own": true,
        "primary": true,
        "parallel": false,
        "notes": "average of 5 trials",
        "caveat": "",
        "human_verified": true,
        "human_verified_on": "2026-10-17",
        "check": "human",
        "corroborated": true,
        "corroborated_on": "2026-10-19",
        "corroborated_by": [
          {
            "url": "https://blog.google/innovation-and-ai/models-and-research/gemini-models/gemini-4-argon/",
            "name": "Gemini 4 Argon",
            "title": "Gemini 4 Argon: our next era of frontier intelligence",
            "lab": "google",
            "date": "2026-09-30",
            "printed": "67.4%",
            "where": "Benchmark table image; row 'DeepSWE v1.1'; column claude-fable-5-1"
          },
          {
            "url": "https://openai.com/index/gpt-6-astra",
            "name": "GPT-6 Astra",
            "title": "GPT-6 Astra: A new generation of intelligence",
            "lab": "openai",
            "date": "2026-09-03",
            "printed": "67.4%",
            "where": "table 2 \"DeepSWE v1.1\" row, \"Claude Fable 5.1\" column"
          }
        ]
      },
      {
        "id": "claude-fable-5-1:terminal-bench-4-0:default:1",
        "model": "claude-fable-5-1",
        "model_name": "Claude Fable 5.1",
        "model_date": "2026-09-01",
        "event": "https://frontierlog.ai/event/2026-09-01-claude-fable-5-1-mythos-5-1",
        "benchmark": "terminal-bench-4-0",
        "benchmark_name": "Terminal-Bench 4.0",
        "setting": "default",
        "setting_name": "",
        "score": 55.8,
        "unit": "%",
        "printed": "55.8%",
        "reported_by": "anthropic",
        "run_by": null,
        "label": "Fable 5.1",
        "source": "https://www.anthropic.com/claude-fable-and-mythos-5-1",
        "source_title": "Introducing Claude Fable 5.1 and Claude Mythos 5.1",
        "source_date": "2026-09-01",
        "where": "benchmark table, row 'Terminal-Bench 4.0', column 'Fable 5.1' (the cell also prints a Mythos 5.1 figure)",
        "own": true,
        "primary": true,
        "parallel": false,
        "notes": "",
        "caveat": "",
        "human_verified": true,
        "human_verified_on": "2026-10-17",
        "check": "human",
        "corroborated": true,
        "corroborated_on": "2026-10-19",
        "corroborated_by": [
          {
            "url": "https://www.anthropic.com/claude-fable-5-1-mythos-5-1-system-card",
            "name": "Claude Fable 5.1 and Mythos 5.1 card",
            "title": "Claude Fable 5.1 and Claude Mythos 5.1 System Card",
            "lab": "anthropic",
            "date": "2026-09-01",
            "printed": "55.8%",
            "where": "Section 8.6 (p.171) sentence: \"Claude Fable 5.1 scored 55.8%\" (max effort, Claude Code --bare)"
          },
          {
            "url": "https://www.anthropic.com/claude-opus-5-5-system-card",
            "name": "Claude Opus 5.5 card",
            "title": "Claude Opus 5.5 System Card",
            "lab": "anthropic",
            "date": "2026-09-22",
            "printed": "55.8",
            "where": "Table 8.1.A (p.174), row Terminal-Bench 4.0, column Claude Fable 5.1"
          },
          {
            "url": "https://www.anthropic.com/claude-sonnet-5-5-system-card",
            "name": "Claude Sonnet 5.5 card",
            "title": "Claude Sonnet 5.5 System Card",
            "lab": "anthropic",
            "date": "2026-09-28",
            "printed": "55.8%",
            "where": "Section 8.5 (p.113) sentence: \"Claude Fable 5.1 scored 55.8%\""
          },
          {
            "url": "https://www.anthropic.com/claude-opus-5-5",
            "name": "Claude Opus 5.5",
            "title": "Introducing Claude Opus 5.5",
            "lab": "anthropic",
            "date": "2026-09-22",
            "printed": "55.8%",
            "where": "HTML benchmark table under 'Performance and cost-effectiveness', row Terminal-Bench 4.0¹, column Fable 5.1"
          },
          {
            "url": "https://openai.com/index/gpt-6-astra",
            "name": "GPT-6 Astra",
            "title": "GPT-6 Astra: A new generation of intelligence",
            "lab": "openai",
            "date": "2026-09-03",
            "printed": "55.8%",
            "where": "table 2 \"Terminal-Bench 4.0\" row, \"Claude Fable 5.1\" column"
          }
        ],
        "source_capture": "https://frontierlog.ai/captures/f381a9ad69b68272.png"
      },
      {
        "id": "claude-fable-5-1:osworld-2-0:offline-partial:1",
        "model": "claude-fable-5-1",
        "model_name": "Claude Fable 5.1",
        "model_date": "2026-09-01",
        "event": "https://frontierlog.ai/event/2026-09-01-claude-fable-5-1-mythos-5-1",
        "benchmark": "osworld-2-0",
        "benchmark_name": "OSWorld 2.0",
        "setting": "offline-partial",
        "setting_name": "Offline set, partial score",
        "score": 77.9,
        "unit": "%",
        "printed": "77.9%",
        "reported_by": "anthropic",
        "run_by": null,
        "label": "Fable 5.1",
        "source": "https://www.anthropic.com/claude-fable-and-mythos-5-1",
        "source_title": "Introducing Claude Fable 5.1 and Claude Mythos 5.1",
        "source_date": "2026-09-01",
        "where": "benchmark table (HTML), row 'Computer use / OSWorld 2.0 [2]', column 'Fable 5.1', the value tagged 'partial'",
        "own": true,
        "primary": true,
        "parallel": false,
        "notes": "partial score; August 2026 task release, not comparable to earlier OSWorld 2.0 scores; tasks where safeguards intervened scored zero",
        "caveat": "",
        "human_verified": true,
        "human_verified_on": "2026-10-18",
        "check": "human",
        "corroborated": false,
        "corroborated_on": null,
        "corroborated_by": [],
        "source_capture": "https://frontierlog.ai/captures/f381a9ad69b68272.png"
      },
      {
        "id": "claude-fable-5-1:terminal-bench-science-0-1:default:1",
        "model": "claude-fable-5-1",
        "model_name": "Claude Fable 5.1",
        "model_date": "2026-09-01",
        "event": "https://frontierlog.ai/event/2026-09-01-claude-fable-5-1-mythos-5-1",
        "benchmark": "terminal-bench-science-0-1",
        "benchmark_name": "Terminal-Bench Science 0.1",
        "setting": "default",
        "setting_name": "",
        "score": 52.6,
        "unit": "%",
        "printed": "52.6%",
        "reported_by": "anthropic",
        "run_by": null,
        "label": "Fable 5.1",
        "source": "https://www.anthropic.com/claude-fable-and-mythos-5-1",
        "source_title": "Introducing Claude Fable 5.1 and Claude Mythos 5.1",
        "source_date": "2026-09-01",
        "where": "benchmark table (HTML), row 'Agentic scientific research, Terminal-Bench-Science 0.1 [1]', column 'Fable 5.1'",
        "own": true,
        "primary": true,
        "parallel": false,
        "notes": "standard error ±3.5 to 4.5 points",
        "caveat": "",
        "human_verified": true,
        "human_verified_on": "2026-10-19",
        "check": "human",
        "corroborated": true,
        "corroborated_on": "2026-10-19",
        "corroborated_by": [
          {
            "url": "https://www.anthropic.com/claude-fable-5-1-mythos-5-1-system-card",
            "name": "Claude Fable 5.1 and Mythos 5.1 card",
            "title": "Claude Fable 5.1 and Claude Mythos 5.1 System Card",
            "lab": "anthropic",
            "date": "2026-09-01",
            "printed": "52.6%",
            "where": "Table 8.1.A, Terminal-Bench-Science 0.1 row, Claude Fable 5.1/Mythos 5.1 column"
          },
          {
            "url": "https://www.anthropic.com/claude-opus-5-5",
            "name": "Claude Opus 5.5",
            "title": "Introducing Claude Opus 5.5",
            "lab": "anthropic",
            "date": "2026-09-22",
            "printed": "52.6%",
            "where": "benchmark table, Terminal-Bench-Science 0.1 row, Fable 5.1 column"
          },
          {
            "url": "https://www.anthropic.com/claude-opus-5-5-system-card",
            "name": "Claude Opus 5.5 card",
            "title": "Claude Opus 5.5 System Card",
            "lab": "anthropic",
            "date": "2026-09-22",
            "printed": "52.6",
            "where": "Table 8.1.A, Terminal-Bench-Science 0.1 row, Claude Fable 5.1 column"
          }
        ],
        "source_capture": "https://frontierlog.ai/captures/f381a9ad69b68272.png"
      },
      {
        "id": "claude-fable-5-1:frontiercode-1-1:main:1",
        "model": "claude-fable-5-1",
        "model_name": "Claude Fable 5.1",
        "model_date": "2026-09-01",
        "event": "https://frontierlog.ai/event/2026-09-01-claude-fable-5-1-mythos-5-1",
        "benchmark": "frontiercode-1-1",
        "benchmark_name": "FrontierCode 1.1",
        "setting": "main",
        "setting_name": "Main set",
        "score": 50.9,
        "unit": "%",
        "printed": "50.9%",
        "reported_by": "anthropic",
        "run_by": null,
        "label": "Claude Fable 5.1",
        "source": "https://www.anthropic.com/claude-fable-5-1-mythos-5-1-system-card",
        "source_title": "Claude Fable 5.1 and Claude Mythos 5.1 System Card",
        "source_date": "2026-09-01",
        "where": "Section 8.4 'FrontierCode', paragraph after the task description, sentence on FrontierCode 1.1 (Main)",
        "own": true,
        "primary": true,
        "parallel": false,
        "notes": "medium effort",
        "caveat": "",
        "human_verified": true,
        "human_verified_on": "2026-10-19",
        "check": "human",
        "corroborated": false,
        "corroborated_on": null,
        "corroborated_by": []
      },
      {
        "id": "claude-fable-5-1:frontiercode-1-1:extended:1",
        "model": "claude-fable-5-1",
        "model_name": "Claude Fable 5.1",
        "model_date": "2026-09-01",
        "event": "https://frontierlog.ai/event/2026-09-01-claude-fable-5-1-mythos-5-1",
        "benchmark": "frontiercode-1-1",
        "benchmark_name": "FrontierCode 1.1",
        "setting": "extended",
        "setting_name": "Extended set",
        "score": 63.6,
        "unit": "%",
        "printed": "63.6%",
        "reported_by": "anthropic",
        "run_by": null,
        "label": "Claude Fable 5.1",
        "source": "https://www.anthropic.com/claude-fable-5-1-mythos-5-1-system-card",
        "source_title": "Claude Fable 5.1 and Claude Mythos 5.1 System Card",
        "source_date": "2026-09-01",
        "where": "Section 8.4 'FrontierCode', paragraph after the task description, sentence on FrontierCode 1.1 Extended",
        "own": true,
        "primary": true,
        "parallel": false,
        "notes": "medium effort",
        "caveat": "",
        "human_verified": true,
        "human_verified_on": "2026-10-19",
        "check": "human",
        "corroborated": false,
        "corroborated_on": null,
        "corroborated_by": []
      },
      {
        "id": "claude-fable-5-1:automationbench:default:1",
        "model": "claude-fable-5-1",
        "model_name": "Claude Fable 5.1",
        "model_date": "2026-09-01",
        "event": "https://frontierlog.ai/event/2026-09-01-claude-fable-5-1-mythos-5-1",
        "benchmark": "automationbench",
        "benchmark_name": "AutomationBench",
        "setting": "default",
        "setting_name": "",
        "score": 31.4,
        "unit": "%",
        "printed": "31.4%",
        "reported_by": "anthropic",
        "run_by": null,
        "label": "Fable 5.1",
        "source": "https://www.anthropic.com/claude-fable-and-mythos-5-1",
        "source_title": "Introducing Claude Fable 5.1 and Claude Mythos 5.1",
        "source_date": "2026-09-01",
        "where": "benchmark table (HTML), row 'Business workflows, AutomationBench', column 'Fable 5.1'",
        "own": true,
        "primary": true,
        "parallel": false,
        "notes": "Zapier leaderboard, private held-out set; max effort; with production safeguards",
        "caveat": "",
        "human_verified": false,
        "human_verified_on": null,
        "check": "corroborated",
        "corroborated": true,
        "corroborated_on": "2026-10-19",
        "corroborated_by": [
          {
            "url": "https://www.anthropic.com/claude-fable-5-1-mythos-5-1-system-card",
            "name": "Claude Fable 5.1 and Mythos 5.1 card",
            "title": "Claude Fable 5.1 and Claude Mythos 5.1 System Card",
            "lab": "anthropic",
            "date": "2026-09-01",
            "printed": "31.4",
            "where": "Table 8.1.A Capability evaluation summary, row AutomationBench, column Claude Fable 5.1/Mythos 5.1 (also 8.15.6 text: 'Claude Fable 5.1 at max effort scored 31.4%')"
          },
          {
            "url": "https://www.anthropic.com/claude-opus-5-5-system-card",
            "name": "Claude Opus 5.5 card",
            "title": "Claude Opus 5.5 System Card",
            "lab": "anthropic",
            "date": "2026-09-22",
            "printed": "31.4",
            "where": "Table 8.1.A, row AutomationBench, column Claude Fable 5.1 (also 8.14.6 text: 'Claude Fable 5.1 at max effort at 31.4%')"
          },
          {
            "url": "https://www.anthropic.com/claude-opus-5-5",
            "name": "Claude Opus 5.5",
            "title": "Introducing Claude Opus 5.5",
            "lab": "anthropic",
            "date": "2026-09-22",
            "printed": "31.4%",
            "where": "Benchmark table, row Business workflows AutomationBench, column Fable 5.1"
          }
        ],
        "source_capture": "https://frontierlog.ai/captures/f381a9ad69b68272.png"
      },
      {
        "id": "claude-fable-5-1:frontiercode-1-1:main:2",
        "model": "claude-fable-5-1",
        "model_name": "Claude Fable 5.1",
        "model_date": "2026-09-01",
        "event": "https://frontierlog.ai/event/2026-09-01-claude-fable-5-1-mythos-5-1",
        "benchmark": "frontiercode-1-1",
        "benchmark_name": "FrontierCode 1.1",
        "setting": "main",
        "setting_name": "Main set",
        "score": 50.3,
        "unit": "%",
        "printed": "50.3%",
        "reported_by": "anthropic",
        "run_by": null,
        "label": "Fable 5.1",
        "source": "https://www.anthropic.com/claude-opus-5-5",
        "source_title": "Introducing Claude Opus 5.5",
        "source_date": "2026-09-22",
        "where": "benchmark table (HTML), row 'Agentic coding, FrontierCode v1.1 (Main)', column 'Fable 5.1'",
        "own": false,
        "primary": false,
        "parallel": false,
        "notes": "run by Cognition in Claude Code",
        "caveat": "",
        "human_verified": false,
        "human_verified_on": null,
        "check": "corroborated",
        "corroborated": true,
        "corroborated_on": "2026-10-19",
        "corroborated_by": [
          {
            "url": "https://www.anthropic.com/claude-opus-5-5-system-card",
            "name": "Claude Opus 5.5 card",
            "title": "Claude Opus 5.5 System Card",
            "lab": "anthropic",
            "date": "2026-09-22",
            "printed": "50.3",
            "where": "Table 8.1.A, row FrontierCode v1.1 (Main), column Claude Fable 5.1 (table is max effort)"
          }
        ],
        "source_capture": "https://frontierlog.ai/captures/ca3ad55d7ec61f3c.png"
      },
      {
        "id": "claude-fable-5-1:frontiercode-1-1:main:3",
        "model": "claude-fable-5-1",
        "model_name": "Claude Fable 5.1",
        "model_date": "2026-09-01",
        "event": "https://frontierlog.ai/event/2026-09-01-claude-fable-5-1-mythos-5-1",
        "benchmark": "frontiercode-1-1",
        "benchmark_name": "FrontierCode 1.1",
        "setting": "main",
        "setting_name": "Main set",
        "score": 52.8,
        "unit": "%",
        "printed": "52.8%",
        "reported_by": "anthropic",
        "run_by": null,
        "label": "Claude Fable 5.1",
        "source": "https://www.anthropic.com/claude-opus-5-5-system-card",
        "source_title": "Claude Opus 5.5 System Card",
        "source_date": "2026-09-22",
        "where": "Section 8.4 'FrontierCode', paragraph ranking Opus 5.5, the Claude Fable 5.1 figure in the FrontierCode (Main) sentence",
        "own": false,
        "primary": false,
        "parallel": false,
        "notes": "best effort level; run by Cognition in Claude Code",
        "caveat": "",
        "human_verified": true,
        "human_verified_on": "2026-10-20",
        "check": "human",
        "corroborated": false,
        "corroborated_on": null,
        "corroborated_by": []
      },
      {
        "id": "claude-fable-5-1:osworld-2-1:partial:1",
        "model": "claude-fable-5-1",
        "model_name": "Claude Fable 5.1",
        "model_date": "2026-09-01",
        "event": "https://frontierlog.ai/event/2026-09-01-claude-fable-5-1-mythos-5-1",
        "benchmark": "osworld-2-1",
        "benchmark_name": "OSWorld 2.1",
        "setting": "partial",
        "setting_name": "Full set, partial score",
        "score": 80.7,
        "unit": "%",
        "printed": "80.7%",
        "reported_by": "anthropic",
        "run_by": null,
        "label": "Fable 5.1",
        "source": "https://www.anthropic.com/claude-opus-5-5",
        "source_title": "Introducing Claude Opus 5.5",
        "source_date": "2026-09-22",
        "where": "benchmark table (HTML), row 'Computer use / OSWorld 2.1', column 'Fable 5.1', the value tagged 'partial'",
        "own": false,
        "primary": true,
        "parallel": false,
        "notes": "max effort; mean of 5 runs; September 10, 2026 task files; the system card labels it OSWorld 2.0",
        "caveat": "",
        "human_verified": false,
        "human_verified_on": null,
        "check": "corroborated",
        "corroborated": true,
        "corroborated_on": "2026-10-20",
        "corroborated_by": [
          {
            "url": "https://www.anthropic.com/claude-opus-5-5-system-card",
            "name": "Claude Opus 5.5 card",
            "title": "Claude Opus 5.5 System Card",
            "lab": "anthropic",
            "date": "2026-09-22",
            "printed": "80.7%",
            "where": "section 8.13.3 OSWorld 2.0 (p. 206), sentence: 'Claude Fable 5.1 scored 80.7% partial and 42.8% strict pass'; also 8.1 Evaluation summary, row 'OSWorld 2.0 (partial/strict)', column Claude Fable 5.1: '80.7/42.8', and Figure 8.13.3.A bar label 80.7"
          }
        ],
        "source_capture": "https://frontierlog.ai/captures/ca3ad55d7ec61f3c.png"
      }
    ]
  }
}
