{
  "schema": "fak.cross-agent-ablation.v1",
  "regime": "B (nondeterministic; external model varies; the WorkloadHash guard does NOT apply)",
  "provenance": {
    "app_version": "0.32.0",
    "command": "python tools/cross_agent_ablate.py run --task pong --k 5",
    "os": "win32",
    "generated_by": "tools/cross_agent_ablate.py",
    "wall_clock_utc": "2026-06-25T01:20:11Z"
  },
  "task": {
    "id": "pong",
    "prompt": "Create a file named RESULT.txt in the current directory containing exactly the single word PONG and nothing else. Use your file tools. Then reply done.",
    "success_check": "RESULT.txt strip()=='PONG'"
  },
  "k_reps": 5,
  "headline_model": "claude-opus-4-8",
  "validity": {
    "success_gate": "no 'saved' number unless both.completed && both.success",
    "variance": "mean +/- CI95 (Student-t) over K>=5 reps; external models are nondeterministic",
    "model_named": "each arm names its model; kernel-efficiency refused unless model held constant",
    "decompose": "kernel-efficiency (model constant) and agent-capability (model varies) as TWO numbers"
  },
  "arms": [
    {
      "arm": "claude_code",
      "model": "claude-opus-4-8",
      "models_seen": [
        "claude-opus-4-8"
      ],
      "reps": 5,
      "completed_reps": 5,
      "success_reps": 5,
      "success_rate": 1.0,
      "metrics": {
        "output_tokens": {
          "mean": 126.8,
          "ci95": 13.9741,
          "n": 5
        },
        "input_tokens": {
          "mean": 2503.0,
          "ci95": 0.0,
          "n": 5
        },
        "provider_cache_read_tokens": {
          "mean": 42619.4,
          "ci95": 4.0799,
          "n": 5
        },
        "cache_creation_tokens": {
          "mean": 6955.4,
          "ci95": 18.1101,
          "n": 5
        },
        "total_input_tokens": {
          "mean": 52077.8,
          "ci95": 21.4022,
          "n": 5
        },
        "turns": {
          "mean": 2.0,
          "ci95": 0.0,
          "n": 5
        },
        "wall_seconds": {
          "mean": 8.2747,
          "ci95": 2.3289,
          "n": 5
        }
      },
      "raw_reps": [
        {
          "arm": "claude_code",
          "model": "claude-opus-4-8",
          "completed": true,
          "success": true,
          "turns": 2,
          "tokens": {
            "input": 2503,
            "output": 138,
            "provider_cache_read": 42621,
            "cache_create": 6969
          },
          "tools": {},
          "wall_seconds": 11.531
        },
        {
          "arm": "claude_code",
          "model": "claude-opus-4-8",
          "completed": true,
          "success": true,
          "turns": 2,
          "tokens": {
            "input": 2503,
            "output": 118,
            "provider_cache_read": 42617,
            "cache_create": 6943
          },
          "tools": {},
          "wall_seconds": 7.765
        },
        {
          "arm": "claude_code",
          "model": "claude-opus-4-8",
          "completed": true,
          "success": true,
          "turns": 2,
          "tokens": {
            "input": 2503,
            "output": 140,
            "provider_cache_read": 42621,
            "cache_create": 6971
          },
          "tools": {},
          "wall_seconds": 6.6784
        },
        {
          "arm": "claude_code",
          "model": "claude-opus-4-8",
          "completed": true,
          "success": true,
          "turns": 2,
          "tokens": {
            "input": 2503,
            "output": 121,
            "provider_cache_read": 42623,
            "cache_create": 6955
          },
          "tools": {},
          "wall_seconds": 7.6572
        },
        {
          "arm": "claude_code",
          "model": "claude-opus-4-8",
          "completed": true,
          "success": true,
          "turns": 2,
          "tokens": {
            "input": 2503,
            "output": 117,
            "provider_cache_read": 42615,
            "cache_create": 6939
          },
          "tools": {},
          "wall_seconds": 7.7417
        }
      ]
    },
    {
      "arm": "claude_code+fak",
      "model": "claude-opus-4-8",
      "models_seen": [
        "claude-opus-4-8"
      ],
      "reps": 5,
      "completed_reps": 5,
      "success_reps": 5,
      "success_rate": 1.0,
      "metrics": {
        "output_tokens": {
          "mean": 124.0,
          "ci95": 10.4608,
          "n": 5
        },
        "input_tokens": {
          "mean": 2144.0,
          "ci95": 0.0,
          "n": 5
        },
        "provider_cache_read_tokens": {
          "mean": 72506.2,
          "ci95": 46.4049,
          "n": 5
        },
        "cache_creation_tokens": {
          "mean": 6413.2,
          "ci95": 45.9208,
          "n": 5
        },
        "total_input_tokens": {
          "mean": 81063.4,
          "ci95": 91.7912,
          "n": 5
        },
        "turns": {
          "mean": 2.0,
          "ci95": 0.0,
          "n": 5
        },
        "wall_seconds": {
          "mean": 6.1219,
          "ci95": 0.9387,
          "n": 5
        }
      },
      "raw_reps": [
        {
          "arm": "claude_code+fak",
          "model": "claude-opus-4-8",
          "completed": true,
          "success": true,
          "turns": 2,
          "tokens": {
            "input": 2144,
            "output": 121,
            "provider_cache_read": 72573,
            "cache_create": 6478
          },
          "tools": {},
          "wall_seconds": 5.2235,
          "adjudication": {
            "allowed": 1,
            "denied": 0,
            "repaired": 0,
            "quarantined": 0,
            "deferred": 0,
            "vdso_hits": 0,
            "journal_rows": 1,
            "journal": "guard-audit.jsonl"
          }
        },
        {
          "arm": "claude_code+fak",
          "model": "claude-opus-4-8",
          "completed": true,
          "success": true,
          "turns": 2,
          "tokens": {
            "input": 2144,
            "output": 119,
            "provider_cache_read": 72488,
            "cache_create": 6389
          },
          "tools": {},
          "wall_seconds": 5.5735,
          "adjudication": {
            "allowed": 1,
            "denied": 0,
            "repaired": 0,
            "quarantined": 0,
            "deferred": 0,
            "vdso_hits": 0,
            "journal_rows": 1,
            "journal": "guard-audit.jsonl"
          }
        },
        {
          "arm": "claude_code+fak",
          "model": "claude-opus-4-8",
          "completed": true,
          "success": true,
          "turns": 2,
          "tokens": {
            "input": 2144,
            "output": 121,
            "provider_cache_read": 72492,
            "cache_create": 6397
          },
          "tools": {},
          "wall_seconds": 7.1576,
          "adjudication": {
            "allowed": 1,
            "denied": 0,
            "repaired": 0,
            "quarantined": 0,
            "deferred": 0,
            "vdso_hits": 0,
            "journal_rows": 1,
            "journal": "guard-audit.jsonl"
          }
        },
        {
          "arm": "claude_code+fak",
          "model": "claude-opus-4-8",
          "completed": true,
          "success": true,
          "turns": 2,
          "tokens": {
            "input": 2144,
            "output": 139,
            "provider_cache_read": 72488,
            "cache_create": 6409
          },
          "tools": {},
          "wall_seconds": 6.2234,
          "adjudication": {
            "allowed": 1,
            "denied": 0,
            "repaired": 0,
            "quarantined": 0,
            "deferred": 0,
            "vdso_hits": 0,
            "journal_rows": 1,
            "journal": "guard-audit.jsonl"
          }
        },
        {
          "arm": "claude_code+fak",
          "model": "claude-opus-4-8",
          "completed": true,
          "success": true,
          "turns": 2,
          "tokens": {
            "input": 2144,
            "output": 120,
            "provider_cache_read": 72490,
            "cache_create": 6393
          },
          "tools": {},
          "wall_seconds": 6.4317,
          "adjudication": {
            "allowed": 1,
            "denied": 0,
            "repaired": 0,
            "quarantined": 0,
            "deferred": 0,
            "vdso_hits": 0,
            "journal_rows": 1,
            "journal": "guard-audit.jsonl"
          }
        }
      ],
      "adjudication_totals": {
        "allowed": 5,
        "denied": 0,
        "repaired": 0,
        "quarantined": 0,
        "deferred": 0,
        "vdso_hits": 0,
        "journal_rows": 5
      }
    }
  ],
  "comparison": {
    "baseline_arm": "claude_code",
    "treatment_arm": "claude_code+fak",
    "gated": true,
    "variance_ok": true,
    "kernel_efficiency": {
      "model": "claude-opus-4-8",
      "output_tokens_ratio": 0.9779,
      "total_input_tokens_ratio": 1.5566,
      "turns_ratio": 1.0,
      "saved_output_tokens": 2.8,
      "saved_total_input_tokens": -28985.6,
      "note": "model held constant -> the delta is the kernel's, not the model's; +saved = kernel cheaper, -saved = kernel overhead"
    },
    "agent_capability": {
      "baseline": {
        "arm": "claude_code",
        "success_rate": 1.0
      },
      "treatment": {
        "arm": "claude_code+fak",
        "success_rate": 1.0
      },
      "note": "success rate is the MODEL's capability and varies across reps; with both arms on one model it is ~held here, so kernel-efficiency is the live number"
    }
  }
}
