Uses the Kozeny-Carman relation with supplied porosity and pore diameter, then applies Dar

[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0x2880EdfFF13100677Bf97A3CBdF3Bc34771C4E5E",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "3000",
    "maxTimeoutSeconds": 300
  }
]

{
  "bazaar": {
    "info": {
      "input": {
        "body": {
          "fluid_dynamic_viscosity_pa_s": 0.001,
          "kozeny_constant": 180,
          "mean_pore_diameter_um": 180,
          "porosity_fraction": 0.72,
          "pressure_drop_pa": 1200,
          "scaffold_thickness_mm": 4
        },
        "bodyType": "json",
        "method": "POST",
        "type": "http"
      }
    },
    "schema": {
      "$schema": "https://json-schema.org/draft/2020-12/schema",
      "properties": {
        "input": {
          "additionalProperties": false,
          "properties": {
            "body": {
              "additionalProperties": false,
              "properties": {
                "fluid_dynamic_viscosity_pa_s": {
                  "maximum": 1000000,
                  "minimum": 1e-9,
                  "type": "number"
                },
                "kozeny_constant": {
                  "maximum": 10000,
                  "minimum": 1,
                  "type": "number"
                },
                "mean_pore_diameter_um": {
                  "maximum": 1000000,
                  "minimum": 0.001,
                  "type": "number"
                },
                "porosity_fraction": {
                  "maximum": 0.99,
                  "minimum": 0.01,
                  "type": "number"
                },
                "pressure_drop_pa": {
                  "maximum": 1000000000000,
                  "minimum": -1000000000000,
                  "type": "number"
                },
                "scaffold_thickness_mm": {
                  "maximum": 1000000,
                  "minimum": 0.001,
                  "type": "number"
                }
              },
              "required": [
                "porosity_fraction",
                "mean_pore_diameter_um",
                "scaffold_thickness_mm",
                "fluid_dynamic_viscosity_pa_s",
                "pressure_drop_pa"
              ],
              "type": "object"
            },
            "bodyType": {
              "enum": [
                "json",
                "form-data",
                "text"
              ],
              "type": "string"
            },
            "method": {
              "enum": [
                "POST",
                "PUT",
                "PATCH"
              ],
              "type": "string"
            },
            "type": {
              "const": "http",
              "type": "string"
            }
          },
          "required": [
            "type",
            "method",
            "bodyType",
            "body"
          ],
          "type": "object"
        }
      },
      "required": [
        "input"
      ],
      "type": "object"
    }
  }
}

curl "https://bio.halowerk.com/v1/tissue-scaffold"
# -> 402 Payment Required, accepts[] lists how to pay
# retry with a PAYMENT-SIGNATURE (or PAYMENT header) once paid

const res = await fetch("https://bio.halowerk.com/v1/tissue-scaffold");
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://bio.halowerk.com/v1/tissue-scaffold")
if res.status_code == 402:
    accepts = res.json()["accepts"]
    # pay one of accepts[] via an x402 client, then retry with the payment header