PRODUCT

Four Cad

Four Cad is the CAD reasoning workspace on Rowe 1.0: upload native CAD or drawings, convert to cad_scene, run compare/optimize, and inspect reasoning_scene overlays — without flattening engineering structure to text.

Upload

Add OBJ, STL, or point-cloud JSON in the Four Cad workbench. Native CAD formats use the converter route when configured.

Analyze

Four Cad converts STEP, IGES, DXF, PDF, SVG, and draw.io into native cad_scene input, then runs Rowe compare/optimize without flattening drawings to text.

Inspect

Review reasoning_scene.v2 overlays, issues, measurements, comparisons, geometry changes, feature-tree-aware suggestions, and grounded text.

Where Four Cad fits

Four Cad is the product workspace. Rowe is the model API underneath. API docs stay focused on Rowe request and response contracts; Four Cad docs describe the CAD workflow built on those contracts.

Open Four Cad →Read Rowe API docs →

Current support

Browser path is live for OBJ, STL, and JSON point-cloud scenes. Native CAD and drawings (STEP, IGES, DXF, PDF, SVG) go through the hosted converter into cad_scene. SolidWorks native files are rejected (export STEP). Public API path: CAD demo path.

Supported browser uploadsOBJ, STL, JSON

Parsed in the browser and converted into Rowe point_cloud_scene input.

Native CAD and drawingsSTEP, IGES, DXF, PDF, SVG

Converted into Rowe cad_scene input with structured B-rep or drawing topology. Point clouds are optional for visualization only.

Diagramsdraw.io (.drawio, .xml)

Nodes with absolute bounding boxes, containers, directed connectors, labels, and derived spatial relations (contains, left_of, above, overlaps).

Workbench route/dashboard/four-cad

Authenticated dashboard product surface for upload, analysis, comparison, visualization, and report export.

Run route/api/dashboard/four-cad/run

Authenticated dashboard route that sends the generated Rowe request through the existing spatial response runtime.

Primary outputreasoning_scene

Renderable 3D reasoning data with objects, relations, overlays, measurements, issues, comparisons, and geometry changes.

Generated Rowe request

Four Cad sends Rowe the same spatial contracts you can send to the Responses API directly. Native CAD uploads become cad_scene with B-rep solids, drawing entities, dimensions, and optional feature trees. OBJ/STL still use point_cloud_scene.

JSON

{
  "model": "rowe-1.0",
  "input": {
    "task_type": "compare",
    "object_id": "candidate-bracket",
    "secondary_id": "baseline-bracket",
    "detail": "standard",
    "goal": {
      "product": "Four Cad",
      "mode": "compare",
      "objective": "Compare baseline and candidate CAD models without flattening them to text."
    },
    "cad_scene": {
      "scene_id": "four-cad-candidate",
      "schema_version": "four-cad.cad_scene.v1",
      "source_format": "step",
      "units": "millimeter",
      "structure": {
        "kind": "brep",
        "solids": [{ "id": "candidate", "volume": 1350, "bounding_box": { "x_min": 0.08, "x_max": 1.43, "y_min": 0, "y_max": 0.55, "z_min": 0.45, "z_max": 0.95 } }]
      }
    },
    "previous_cad_scene": {
      "scene_id": "four-cad-baseline",
      "schema_version": "four-cad.cad_scene.v1",
      "source_format": "step",
      "units": "millimeter",
      "structure": {
        "kind": "brep",
        "solids": [{ "id": "baseline", "volume": 1200, "bounding_box": { "x_min": 0, "x_max": 1.2, "y_min": 0, "y_max": 0.55, "z_min": 0.45, "z_max": 0.95 } }]
      }
    }
  }
}

Native CAD converter

Configure FOUR_CAD_CONVERTER_URL and optionally FOUR_CAD_CONVERTER_TOKEN to proxy STEP, IGES, DXF, PDF, and SVG files to a hosted converter that returns structured extraction data alongside point clouds. Without that configuration, the route returns converter_required with HTTP 501. API consumers can use the public /api/v1/cad/extract endpoint instead.

Terminal

$ curl https://fourechelon.com/api/dashboard/four-cad/convert \
    -H "Cookie: <dashboard session cookie>" \
    -F "file=@assembly.step"