Involute spur gear as exact NURBS: the outline as STEP or IGES curves, a solid when a face

[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0x7Ac7fDc938839dc67C603733AB118d1ece7F9ace",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "30000",
    "maxTimeoutSeconds": 300
  }
]

{
  "bazaar": {
    "info": {
      "input": {
        "method": "GET",
        "queryParams": {
          "backlash": 0,
          "face_width": 10,
          "format": "step",
          "mate": 40,
          "mate_shift": 0,
          "module": 2,
          "pressure_angle": 20,
          "shift": 0,
          "teeth": 20,
          "trace": "1"
        },
        "type": "http"
      }
    },
    "schema": {
      "$schema": "https://json-schema.org/draft/2020-12/schema",
      "properties": {
        "input": {
          "additionalProperties": false,
          "properties": {
            "method": {
              "enum": [
                "GET"
              ],
              "type": "string"
            },
            "queryParams": {
              "properties": {
                "backlash": {
                  "description": "Tooth thickness reduction at the pitch circle, mm; default 0",
                  "type": "number"
                },
                "face_width": {
                  "description": "Face width in mm: when given, the file holds the extruded solid instead of the planar outline",
                  "type": "number"
                },
                "format": {
                  "description": "step, iges, or json for the drawing numbers alone; default step",
                  "type": "string"
                },
                "mate": {
                  "description": "Tooth count of a mating gear: when given, the file holds both gears meshed at the working center distance and the report adds the pair's numbers",
                  "type": "integer"
                },
                "mate_shift": {
                  "description": "The mate's profile shift coefficient; default 0",
                  "type": "number"
                },
                "module": {
                  "description": "Module in mm (pitch diameter / teeth); default 1",
                  "type": "number"
                },
                "pressure_angle": {
                  "description": "Pressure angle in degrees: 14.5, 20 or 25 are the standards; default 20",
                  "type": "number"
                },
                "shift": {
                  "description": "Profile shift coefficient x; a small tooth count needs a positive shift, and the refusal says how much",
                  "type": "number"
                },
                "teeth": {
                  "description": "Number of teeth, 6 to 200",
                  "type": "integer"
                },
                "trace": {
                  "description": "1 to be given the free verification record for this result (the contract, the standards, the checks, the numbers); omitted, nothing extra is included",
                  "type": "string"
                }
              },
              "required": [
                "teeth"
              ],
              "type": "object"
            },
            "type": {
              "const": "http",
              "type": "string"
            }
          },
          "required": [
            "type",
            "method"
          ],
          "type": "object"
        }
      },
      "required": [
        "input"
      ],
      "type": "object"
    }
  }
}

curl "https://genworks.com/demo/gear/cad"
# -> 402 Payment Required, accepts[] lists how to pay
# retry with a PAYMENT-SIGNATURE (or PAYMENT header) once paid

const res = await fetch("https://genworks.com/demo/gear/cad");
if (res.status === 402) {
  const { accepts } = await res.json();
  // pay one of accepts[] via an x402 client, then retry with the payment header
}

import httpx
res = httpx.get("https://genworks.com/demo/gear/cad")
if res.status_code == 402:
    accepts = res.json()["accepts"]
    # pay one of accepts[] via an x402 client, then retry with the payment header