{
  "title": "With and without Perture: exploratory landing-page field study",
  "published": "2026-10-27",
  "scope": "Internal exploratory executions of one core brief; not a randomized or blinded A/B benchmark",
  "timing": {
    "measurement": "Original task-turn duration, task started to task completed, including tooling, publication, and checks. Not human labor time or isolated generation time.",
    "runs": [
      {
        "condition": "Manual assets",
        "date": "2026-10-16",
        "duration_ms": 826555,
        "source": "Codex original task turn 01a146c7-d806-7403-a55b-f27917b056a3"
      },
      {
        "condition": "Connected brand context",
        "date": "2026-10-26",
        "duration_ms": 2097337,
        "source": "Codex original task turn 01a178e2-1e17-7ef0-bb07-b1f9252b5327"
      },
      {
        "condition": "Fresh connected repeat",
        "date": "2026-10-27",
        "duration_ms": 1507683,
        "source": "Codex original task turn 01a17e6b-1f20-7920-88aa-016b488cf3bb"
      }
    ],
    "matched_speedup_claim": false,
    "tokens_and_cost": "No cost or token comparison claimed"
  },
  "fresh_run": {
    "prompt_sha256": "2346d8d7c22c852873032605523e5e5b4de858ac1e264be853caf81376534fd5",
    "new_code_copy_and_image": true,
    "owner_context_fully_blind": false,
    "environment": "Isolated Perture Preview MCP",
    "first_generation": {
      "layout_passed": true,
      "browser_checks_passed": true,
      "source_passed": false,
      "source_findings": [
        {
          "code": "frontend.font.asset_traceability",
          "file": "dist/styles.css",
          "message": "@font-face uses a file that is not traceable to an approved Perture font asset.",
          "severity": "error"
        }
      ],
      "layout_adjustments": 0,
      "measured_widths": [
        320,
        390,
        639,
        640,
        960,
        1280,
        1440,
        2399,
        2400,
        3200
      ],
      "metrics": [
        {
          "width": 320,
          "gap_px": null,
          "center_offset_px": null,
          "findings": [],
          "issues": []
        },
        {
          "width": 390,
          "gap_px": null,
          "center_offset_px": null,
          "findings": [],
          "issues": []
        },
        {
          "width": 639,
          "gap_px": null,
          "center_offset_px": null,
          "findings": [],
          "issues": []
        },
        {
          "width": 640,
          "gap_px": 19,
          "center_offset_px": 2.4921875,
          "findings": [],
          "issues": []
        },
        {
          "width": 960,
          "gap_px": 30,
          "center_offset_px": 2.5,
          "findings": [],
          "issues": []
        },
        {
          "width": 1280,
          "gap_px": 21,
          "center_offset_px": 2.5,
          "findings": [],
          "issues": []
        },
        {
          "width": 1440,
          "gap_px": 21,
          "center_offset_px": 2.5,
          "findings": [],
          "issues": []
        },
        {
          "width": 2399,
          "gap_px": 21,
          "center_offset_px": 2.5,
          "findings": [],
          "issues": []
        },
        {
          "width": 2400,
          "gap_px": 41,
          "center_offset_px": 2.5,
          "findings": [],
          "issues": []
        },
        {
          "width": 3200,
          "gap_px": 41,
          "center_offset_px": 2.5,
          "findings": [],
          "issues": []
        }
      ]
    },
    "font_correction": {
      "reason": "Published font filename required by source traceability checker",
      "old_path": "assets/rethink.ttf",
      "new_path": "assets/RethinkSans-wght.ttf",
      "font_sha256": "c700224149f9248587ccb1e1482bb01c1c779076c8c593720838877ad9643347",
      "bytes_unchanged": true,
      "layout_copy_and_image_changed": false,
      "initial_source_validation_passed": false,
      "initial_layout_passed": true
    },
    "font_visual_equivalence": {
      "passed": true,
      "scope": "Only official font file name and matching source URLs changed; rendered screenshots compared byte for byte",
      "rows": [
        {
          "name": "mobile",
          "width": 390,
          "byte_identical_to_first_generation": true,
          "sha256": "6623ef2e0b7fe43c765440889f43e8308565bef6db4b469eb98c3e9088d30b3b"
        },
        {
          "name": "desktop",
          "width": 1440,
          "byte_identical_to_first_generation": true,
          "sha256": "2e12fb63ddbc59453f0b8b5c0462cc6755850ae0cf626c0a91d7ceb1172556bb"
        },
        {
          "name": "wide",
          "width": 2400,
          "byte_identical_to_first_generation": true,
          "sha256": "d8d6ac1590ca28dfa3b3945c10496381e87885e718a3bac45e597b4e1cd3e5c6"
        }
      ]
    },
    "final": {
      "source_passed": true,
      "traceability_passed": true,
      "geometry_passed": true,
      "source_hash": "59cb775b08af2ce842ca9eefa6e0e0dbf11478f68ee718fd90ef12cf6d51dab3",
      "source_binding": {
        "status": "served_source_matched",
        "files_matched": [
          "dist/assets/RethinkSans-wght.ttf",
          "dist/assets/brand.svg",
          "dist/assets/original.png",
          "dist/index.html",
          "dist/styles.css"
        ],
        "files_missing": [],
        "files_mismatched": [],
        "files_unreadable": [],
        "files_outside_scope": [],
        "local_files_stable": true
      },
      "source_findings": [],
      "geometry_errors": 0
    },
    "measurement_scope": "Gap measures visible text/control bounds to the rendered image element bounds; it does not segment white pixels inside the raster artwork.",
    "artistic_fidelity": "not formally attested; generated shading includes blue and gray tones beyond four literal hex colors",
    "official_component_fidelity": "not_verified: HTML composition uses allowed derived roles rather than an approved executable Figma hero/button",
    "remote_computed_geometry_attestation": false,
    "production_availability_established": false
  },
  "screenshots": [
    {
      "file": "manual-desktop.jpg",
      "sha256": "98aa98f0c79dac365c2c2ffd924025807561fe3d6b15fda9541d46bd8fbf5639",
      "bytes": 89025,
      "transformed_for_article": false
    },
    {
      "file": "manual-mobile.jpg",
      "sha256": "60e762d5bfc3e94087d515da1e51ae651dffa90ea7131bb7430cba4fff8053bd",
      "bytes": 50396,
      "transformed_for_article": false
    },
    {
      "file": "connected-desktop.png",
      "sha256": "2e12fb63ddbc59453f0b8b5c0462cc6755850ae0cf626c0a91d7ceb1172556bb",
      "bytes": 189665,
      "transformed_for_article": false
    },
    {
      "file": "connected-mobile.png",
      "sha256": "6623ef2e0b7fe43c765440889f43e8308565bef6db4b469eb98c3e9088d30b3b",
      "bytes": 59091,
      "transformed_for_article": false
    },
    {
      "file": "connected-earlier-desktop.png",
      "sha256": "7aea33e094d90f71449e9757afbd9814ac424dfdbe4346d386b3f2c77f25f459",
      "bytes": 61890,
      "transformed_for_article": false
    }
  ],
  "limits": [
    "Different execution dates, tools, and published brand snapshots",
    "Identical model state not established",
    "Local rendered geometry evidence is separate from remote computed-layout attestation",
    "The manual output is a functioning result, not a deliberately degraded baseline",
    "No blinded aesthetic score, general speedup, cost savings, or customer outcome claimed"
  ]
}