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API happy path

Canonical paid-key call: POST /api/v1/responses with model rowe-1.0 and a four-cad.cad_scene.v1 input. Use an existing entitled key; this page does not walk Stripe Checkout.

Canonical paid-key call

Use an entitled key ($FOUR_ECHELON_API_KEY). This page does not run Stripe Checkout. Prefer cad_scene for engineering demos.

POST → https://fourechelon.com/api/v1/responses

Terminal

curl https://fourechelon.com/api/v1/responses \
  -H "Authorization: Bearer $FOUR_ECHELON_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "rowe-1.0",
    "input": {
      "task_type": "optimize",
      "object_id": "bracket",
      "cad_scene": {
        "scene_id": "bracket-review",
        "schema_version": "four-cad.cad_scene.v1",
        "source_format": "step",
        "units": "millimeter",
        "structure": {
          "kind": "brep",
          "solids": [
            {
              "id": "solid-1",
              "volume": 1250,
              "bounding_box": {
                "x_min": 0,
                "x_max": 120,
                "y_min": 0,
                "y_max": 55,
                "z_min": 0,
                "z_max": 25
              },
              "faces": [{ "face_type": "plane" }]
            }
          ],
          "features": [
            { "id": "base_extrude", "feature_type": "extrude", "parameters": { "depth": 25 } }
          ],
          "dimensions": [
            { "dim_type": "linear", "measurement": 120, "text": "120 mm" }
          ]
        }
      }
    }
  }'

From a CAD file

Extract first, wrap the extraction structure as four-cad.cad_scene.v1, then call Responses. Full curl sequence: CAD demo path.

Terminal

curl https://fourechelon.com/api/v1/cad/extract \
  -H "Authorization: Bearer $FOUR_ECHELON_API_KEY" \
  -F "file=@bracket.step" \
  -F "target_contract=both"

Point-cloud variant

Still valid for sampled geometry and legacy spatial workflows.

Terminal

curl https://fourechelon.com/api/v1/responses \
  -H "Authorization: Bearer $FOUR_ECHELON_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "rowe-1.0",
    "input": {
      "task_type": "fit",
      "object_id": "case",
      "secondary_id": "shelf",
      "point_cloud_scene": {
        "point_clouds": [
          {
            "object_id": "case",
            "kind": "box",
            "points": [
              { "x": 0, "y": 0, "z": 0 },
              { "x": 1, "y": 0, "z": 0 },
              { "x": 0, "y": 1, "z": 1 }
            ]
          }
        ]
      }
    }
  }'