Calc Fena

{
  "count": 2,
  "items": [
    {
      "citation": {
        "authors": "Espinel CH",
        "doi": "10.1001/jama.1976.03270060029022",
        "id": "espinel-1976",
        "source": "JAMA. 1976;236(6):579-581",
        "title": "The FENa test. Use in the differential diagnosis of acute renal failure"
      },
      "creatinine_mg_dl": 2,
      "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
      "espinel_stratum": "prerenal",
      "fena_percent": 0.29,
      "formula": "fena",
      "formula_expression": "FENa_percent = 100 * (urine_sodium_mmol_l * plasma_creatinine_mg_dl) / (plasma_sodium_mmol_l * urine_creatinine_mg_dl)",
      "sodium_mmol_l": 140,
      "urine_creatinine_mg_dl": 100,
      "urine_sodium_mmol_l": 20
    },
    {
      "citation": {
        "authors": "Espinel CH",
        "doi": "10.1001/jama.1976.03270060029022",
        "id": "espinel-1976",
        "source": "JAMA. 1976;236(6):579-581",
        "title": "The FENa test. Use in the differential diagnosis of acute renal failure"
      },
      "creatinine_mg_dl": 2,
      "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
      "espinel_stratum": "prerenal",
      "fena_percent": 0.29,
      "formula": "fena",
      "formula_expression": "FENa_percent = 100 * (urine_sodium_mmol_l * plasma_creatinine_mg_dl) / (plasma_sodium_mmol_l * urine_creatinine_mg_dl)",
      "sodium_mmol_l": 140,
      "urine_creatinine_mg_dl": 100,
      "urine_sodium_mmol_l": 20
    }
  ],
  "path": "/api/calc/fena"
}

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i -X POST 'https://api.magentlab.com/api/calc/fena' \
  -H 'content-type: application/json' \
  --data-raw '{"items":[{"creatinine_mg_dl":2,"creatinine_umol_l":176.84,"sodium_mmol_l":140,"urine_creatinine_mg_dl":100,"urine_creatinine_umol_l":8842,"urine_sodium_mmol_l":20},{"creatinine_mg_dl":2,"creatinine_umol_l":176.84,"sodium_mmol_l":140,"urine_creatinine_mg_dl":100,"urine_creatinine_umol_l":8842,"urine_sodium_mmol_l":20}]}'

# x402 v2 sends the challenge base64-encoded in the PAYMENT-REQUIRED header (v1 sends it in the body).
# To read the header:
curl -sS -g -o /dev/null -D - -X POST 'https://api.magentlab.com/api/calc/fena' \
  -H 'content-type: application/json' \
  --data-raw '{"items":[{"creatinine_mg_dl":2,"creatinine_umol_l":176.84,"sodium_mmol_l":140,"urine_creatinine_mg_dl":100,"urine_creatinine_umol_l":8842,"urine_sodium_mmol_l":20},{"creatinine_mg_dl":2,"creatinine_umol_l":176.84,"sodium_mmol_l":140,"urine_creatinine_mg_dl":100,"urine_creatinine_umol_l":8842,"urine_sodium_mmol_l":20}]}' \
  | grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decode

// npm i @x402/fetch @x402/evm viem
import { wrapFetchWithPayment, x402Client } from "@x402/fetch";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

// Pays at most $0.007 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.007" });
registerExactEvmScheme(client, { signer: privateKeyToAccount(process.env.EVM_PRIVATE_KEY) });
const pay = wrapFetchWithPayment(fetch, client);

// Not sure it's safe to pay? ToolVet checks it first for $0.005. Pay for that from a separate
// client: this one is capped at $0.007 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fapi.magentlab.com%2Fapi%2Fcalc%2Ffena&method=POST
const res = await pay("https://api.magentlab.com/api/calc/fena", {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({
    "items": [
      {
        "creatinine_mg_dl": 2,
        "creatinine_umol_l": 176.84,
        "sodium_mmol_l": 140,
        "urine_creatinine_mg_dl": 100,
        "urine_creatinine_umol_l": 8842,
        "urine_sodium_mmol_l": 20
      },
      {
        "creatinine_mg_dl": 2,
        "creatinine_umol_l": 176.84,
        "sodium_mmol_l": 140,
        "urine_creatinine_mg_dl": 100,
        "urine_creatinine_umol_l": 8842,
        "urine_sodium_mmol_l": 20
      }
    ]
  }),
});
console.log(res.status, await res.text());

# pip install "x402[requests,evm]"
import os
from eth_account import Account
from x402 import x402ClientSync
from x402.http.clients import x402_requests
from x402.mechanisms.evm import EthAccountSigner
from x402.mechanisms.evm.exact.register import register_exact_evm_client

# Pays at most $0.007 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.007"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.post(
        "https://api.magentlab.com/api/calc/fena",
        json={
            "items": [
                {
                    "creatinine_mg_dl": 2,
                    "creatinine_umol_l": 176.84,
                    "sodium_mmol_l": 140,
                    "urine_creatinine_mg_dl": 100,
                    "urine_creatinine_umol_l": 8842,
                    "urine_sodium_mmol_l": 20,
                },
                {
                    "creatinine_mg_dl": 2,
                    "creatinine_umol_l": 176.84,
                    "sodium_mmol_l": 140,
                    "urine_creatinine_mg_dl": 100,
                    "urine_creatinine_umol_l": 8842,
                    "urine_sodium_mmol_l": 20,
                },
            ],
        },
    )
    print(res.status_code, res.text)