{
  "schema_version": "1.0",
  "request": "把明确提供的 015240.step 转换成可修改的 model-spec.json，并保留原始几何作为精确基体",
  "route": {
    "selected_backend": "build123d",
    "runner_skill": "cad",
    "project": "text-to-cad",
    "fallback_order": [
      "simplecadapi",
      "cadam"
    ],
    "workflow_profiles": [],
    "operation": "modify",
    "source_mode": "exact_step_base",
    "modification_mode": "model_spec_parameter_edit"
  },
  "source": {
    "path": "source.step",
    "format": "step",
    "backend": "build123d",
    "sha256": "55aee6a0ad74435503a1e7f108b32c9f403ae9838933e2be6728fb5b2f5cfbd4",
    "immutable_exact_base": true
  },
  "artifacts": [
    {
      "path": "model-spec.json",
      "role": "editable_geometry_contract"
    },
    {
      "path": "imported_015240.step",
      "role": "primary"
    },
    {
      "path": "imported_015240.stl",
      "role": "secondary"
    },
    {
      "path": "source.step",
      "role": "immutable_exact_base"
    }
  ],
  "parameters": {},
  "experience": {
    "library": "../../../../cad-experience-library/library.json",
    "context_kind": "generalized_cad_experience_query",
    "methods_applied": []
  },
  "assumptions": [
    "单位按 STEP 几何和导入工具约定记录为 mm。",
    "原 STEP 不包含可可靠恢复的原生草图、约束或特征历史；后续修改通过 model-spec.json 的命名参数和修改特征表达。",
    "“选中面厚度增加”按直接建模语义解释为源面 #f22 沿其 +Z 法向外移 1.0 mm。",
    "“红圈内的孔缩小”按目标水平板通孔从约 Ø4.8 mm 缩小到 Ø3.6 mm 处理。"
  ],
  "validation": [
    {
      "check": "exact_base_sha256",
      "passed": true,
      "value": "55aee6a0ad74435503a1e7f108b32c9f403ae9838933e2be6728fb5b2f5cfbd4"
    },
    {
      "check": "exact_base_geometry_signature",
      "passed": true,
      "scope": "immutable_source.step",
      "size_mm": [
        26.200001497,
        18.906424738,
        28.2
      ],
      "center_mm": [
        13.100000748,
        7.453212369,
        0.0
      ],
      "solid_count": 1,
      "face_count": 31,
      "edge_count": 87,
      "volume_mm3": 2400.466496
    },
    {
      "check": "model_spec_parameterized_rebuild",
      "passed": true,
      "modified_size_mm": [
        26.200001497,
        18.906424738,
        29.2
      ],
      "modified_center_mm": [
        13.100000748,
        7.453212369,
        0.5
      ],
      "solid_count": 1,
      "volume_mm3": 2476.533646
    },
    {
      "check": "selected_face_f22_extension",
      "passed": true,
      "source_plane_z_mm": 14.1,
      "result_plane_z_mm": 15.1,
      "extension_mm": 1.0,
      "result_face": "#f27"
    },
    {
      "check": "circled_hole_resize",
      "passed": true,
      "center_mm": [
        5.9,
        11.006425,
        0.0
      ],
      "axis": "Z",
      "source_diameter_mm": 4.799996,
      "result_diameter_mm": 3.6,
      "result_face": "#f22"
    },
    {
      "check": "source_to_modified_cad_diff",
      "passed": true,
      "geometry_changed": true,
      "size_delta_mm": [
        0.0,
        0.0,
        1.0
      ],
      "center_delta_mm": [
        0.0,
        0.0,
        0.5
      ]
    },
    {
      "check": "cad_inspect_refs_facts_planes_positioning",
      "passed": true
    },
    {
      "check": "snapshot_review",
      "passed": true,
      "views": [
        "snapshots/iso_20260723T085707Z.png",
        "snapshots/iso_opposite_20260723T085707Z.png",
        "snapshots/top_ortho_20260723T085707Z.png",
        "snapshots/front_ortho_20260723T085707Z.png"
      ]
    }
  ],
  "viewer_links": [
    "http://127.0.0.1:4179/?dir=%2FUsers%2Fjerry%2Flinkhand%2FCadSet%2Ftext-to-cad%2Fmodels%2Fcad-router-v1%2Fimported_015240&file=imported_015240.step"
  ]
}