69trust / 100

Calc Ohfrs

x402 APIFailing, checked 2 h ago

Ottawa Heart Failure Risk Scale (OHFRS; Stiell 2013 derivation). Ten caller-assigned flags (stroke/TIA 1, intubation 2, arrival HR >=110 2, arrival SaO2 <90% 1, walk-test HR >=110 or unable 1, new ischemic ECG 2, urea >=12 mmol/L 1, CO2 >=35 mmol/L 2, troponin at MI level 2, NT-proBNP >=5000 ng/L 1); integer points, max 15. Derivation SAE risk 2.8% to 89.0%. Not a medical device, not a disposition or discharge order, not EHMRG. magent does not walk the patient or read the ECG.

POST

https://api.magentlab.com/api/calc/ohfrs

Price: $0.007; per call in USDC
Uptime: 97.0%; last 30 days
Response time: 163 ms; 606 ms slowest 5%
Last check: Failed; 2 h ago, next any minute now

Run a free test call How to call it

Reliability

All checks passedSome failedAll failedNot checked

Latest check failed 2 h ago: Timed out

Status and outage history · Atom feed · Watch with other listings

How to call it

POST https://api.magentlab.com/api/calc/ohfrs

Each call costs $0.007 in USDC on Base, paid with the request over x402.

Run a free test callOne unpaid request, the way an agent sends it. You see the payment challenge it gets back. Nothing is charged.

Example request

From the listing.

POST https://api.magentlab.com/api/calc/ohfrs
content-type: application/json

{
  "items": [
    {
      "co2_ge_35_mmol_l": false,
      "history_stroke_or_tia": false,
      "hr_arrival_ge_110": false,
      "intubation_respiratory_distress": false,
      "new_ischemic_ecg": false,
      "ntprobnp_ge_5000": false,
      "sao2_lt_90_arrival": false,
      "troponin_mi_level": false,
      "urea_ge_12_mmol_l": false,
      "walk_test_hr_ge_110_or_unable": false
    },
    {
      "co2_ge_35_mmol_l": false,
      "history_stroke_or_tia": false,
      "hr_arrival_ge_110": false,
      "intubation_respiratory_distress": false,
      "new_ischemic_ecg": false,
      "ntprobnp_ge_5000": false,
      "sao2_lt_90_arrival": false,
      "troponin_mi_level": false,
      "urea_ge_12_mmol_l": false,
      "walk_test_hr_ge_110_or_unable": false
    }
  ]
}

Parameters

Parameter	Type	Required	Description
`items`	array of object	Yes

Example response

The provider's example. We can't check it without paying.

Example response, 140 lines

{
  "count": 2,
  "items": [
    {
      "citation": {
        "authors": "Stiell IG, Clement CM, Brison RJ, et al.",
        "doi": "10.1111/acem.12056",
        "id": "stiell-2013",
        "pmid": "23570474",
        "source": "Acad Emerg Med. 2013;20(1):17-26",
        "title": "A risk scoring system to identify emergency department patients with heart failure at high risk for serious adverse events"
      },
      "components": [
        {
          "factor": "history_stroke_or_tia",
          "points": 0,
          "present": false
        },
        {
          "factor": "intubation_respiratory_distress",
          "points": 0,
          "present": false
        },
        {
          "factor": "hr_arrival_ge_110",
          "points": 0,
          "present": false
        },
        {
          "factor": "sao2_lt_90_arrival",
          "points": 0,
          "present": false
        },
        {
          "factor": "walk_test_hr_ge_110_or_unable",
          "points": 0,
          "present": false
        },
        {
          "factor": "new_ischemic_ecg",
          "points": 0,
          "present": false
        },
        {
          "factor": "urea_ge_12_mmol_l",
          "points": 0,
          "present": false
        },
        {
          "factor": "co2_ge_35_mmol_l",
          "points": 0,
          "present": false
        },
        {
          "factor": "troponin_mi_level",
          "points": 0,
          "present": false
        },
        {
          "factor": "ntprobnp_ge_5000",
          "points": 0,
          "present": false
        }
      ],
      "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.",
      "formula": "ohfrs",
      "formula_expression": "OHFRS = history_stroke_or_tia(1) + intubation_respiratory_distress(2) + hr_arrival_ge_110(2) + sao2_lt_90_arrival(1) + walk_test_hr_ge_110_or_unable(1) + new_ischemic_ecg(2) + urea_ge_12_mmol_l(1) + co2_ge_35_mmol_l(2) + troponin_mi_level(2) + ntprobnp_ge_5000(1); Stiell 2013 derivation; max 15; SAE risk varied from 2.8% to 89.0%; admission thresholds of total score 1, 2, or 3 had sensitivities 95.2 / 80.6 / 64.5%",
      "max_score": 15,
      "score": 0
    },
    {
      "citation": {
        "authors": "Stiell IG, Clement CM, Brison RJ, et al.",
        "doi": "10.1111/acem.12056",
        "id": "stiell-2013",
        "pmid": "23570474",
        "source": "Acad Emerg Med. 2013;20(1):17-26",
        "title": "A risk scoring system to identify emergency department patients with heart failure at high risk for serious adverse events"
      },
      "components": [
        {
          "factor": "history_stroke_or_tia",
          "points": 0,
          "present": false
        },
        {
          "factor": "intubation_respiratory_distress",
          "points": 0,
          "present": false
        },
        {
          "factor": "hr_arrival_ge_110",
          "points": 0,
          "present": false
        },
        {
          "factor": "sao2_lt_90_arrival",
          "points": 0,
          "present": false
        },
        {
          "factor": "walk_test_hr_ge_110_or_unable",
          "points": 0,
          "present": false
        },
        {
          "factor": "new_ischemic_ecg",
          "points": 0,
          "present": false
        },
        {
          "factor": "urea_ge_12_mmol_l",
          "points": 0,
          "present": false
        },
        {
          "factor": "co2_ge_35_mmol_l",
          "points": 0,
          "present": false
        },
        {
          "factor": "troponin_mi_level",
          "points": 0,
          "present": false
        },
        {
          "factor": "ntprobnp_ge_5000",
          "points": 0,
          "present": false
        }
      ],
      "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.",
      "formula": "ohfrs",
      "formula_expression": "OHFRS = history_stroke_or_tia(1) + intubation_respiratory_distress(2) + hr_arrival_ge_110(2) + sao2_lt_90_arrival(1) + walk_test_hr_ge_110_or_unable(1) + new_ischemic_ecg(2) + urea_ge_12_mmol_l(1) + co2_ge_35_mmol_l(2) + troponin_mi_level(2) + ntprobnp_ge_5000(1); Stiell 2013 derivation; max 15; SAE risk varied from 2.8% to 89.0%; admission thresholds of total score 1, 2, or 3 had sensitivities 95.2 / 80.6 / 64.5%",
      "max_score": 15,
      "score": 0
    }
  ],
  "path": "/api/calc/ohfrs"
}

Call it from code

The curl command shows the payment challenge. The JavaScript and Python versions pay and call, and never pay more than $0.007.

curl: see the payment challenge

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i -X POST 'https://api.magentlab.com/api/calc/ohfrs' \
  -H 'content-type: application/json' \
  --data-raw '{"items":[{"co2_ge_35_mmol_l":false,"history_stroke_or_tia":false,"hr_arrival_ge_110":false,"intubation_respiratory_distress":false,"new_ischemic_ecg":false,"ntprobnp_ge_5000":false,"sao2_lt_90_arrival":false,"troponin_mi_level":false,"urea_ge_12_mmol_l":false,"walk_test_hr_ge_110_or_unable":false},{"co2_ge_35_mmol_l":false,"history_stroke_or_tia":false,"hr_arrival_ge_110":false,"intubation_respiratory_distress":false,"new_ischemic_ecg":false,"ntprobnp_ge_5000":false,"sao2_lt_90_arrival":false,"troponin_mi_level":false,"urea_ge_12_mmol_l":false,"walk_test_hr_ge_110_or_unable":false}]}'

# 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/ohfrs' \
  -H 'content-type: application/json' \
  --data-raw '{"items":[{"co2_ge_35_mmol_l":false,"history_stroke_or_tia":false,"hr_arrival_ge_110":false,"intubation_respiratory_distress":false,"new_ischemic_ecg":false,"ntprobnp_ge_5000":false,"sao2_lt_90_arrival":false,"troponin_mi_level":false,"urea_ge_12_mmol_l":false,"walk_test_hr_ge_110_or_unable":false},{"co2_ge_35_mmol_l":false,"history_stroke_or_tia":false,"hr_arrival_ge_110":false,"intubation_respiratory_distress":false,"new_ischemic_ecg":false,"ntprobnp_ge_5000":false,"sao2_lt_90_arrival":false,"troponin_mi_level":false,"urea_ge_12_mmol_l":false,"walk_test_hr_ge_110_or_unable":false}]}' \
  | grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decode

JavaScript: pay and call

// 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%2Fohfrs&method=POST
const res = await pay("https://api.magentlab.com/api/calc/ohfrs", {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({
    "items": [
      {
        "co2_ge_35_mmol_l": false,
        "history_stroke_or_tia": false,
        "hr_arrival_ge_110": false,
        "intubation_respiratory_distress": false,
        "new_ischemic_ecg": false,
        "ntprobnp_ge_5000": false,
        "sao2_lt_90_arrival": false,
        "troponin_mi_level": false,
        "urea_ge_12_mmol_l": false,
        "walk_test_hr_ge_110_or_unable": false
      },
      {
        "co2_ge_35_mmol_l": false,
        "history_stroke_or_tia": false,
        "hr_arrival_ge_110": false,
        "intubation_respiratory_distress": false,
        "new_ischemic_ecg": false,
        "ntprobnp_ge_5000": false,
        "sao2_lt_90_arrival": false,
        "troponin_mi_level": false,
        "urea_ge_12_mmol_l": false,
        "walk_test_hr_ge_110_or_unable": false
      }
    ]
  }),
});
console.log(res.status, await res.text());

Python: pay and call

# 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/ohfrs",
        json={
            "items": [
                {
                    "co2_ge_35_mmol_l": False,
                    "history_stroke_or_tia": False,
                    "hr_arrival_ge_110": False,
                    "intubation_respiratory_distress": False,
                    "new_ischemic_ecg": False,
                    "ntprobnp_ge_5000": False,
                    "sao2_lt_90_arrival": False,
                    "troponin_mi_level": False,
                    "urea_ge_12_mmol_l": False,
                    "walk_test_hr_ge_110_or_unable": False,
                },
                {
                    "co2_ge_35_mmol_l": False,
                    "history_stroke_or_tia": False,
                    "hr_arrival_ge_110": False,
                    "intubation_respiratory_distress": False,
                    "new_ischemic_ecg": False,
                    "ntprobnp_ge_5000": False,
                    "sao2_lt_90_arrival": False,
                    "troponin_mi_level": False,
                    "urea_ge_12_mmol_l": False,
                    "walk_test_hr_ge_110_or_unable": False,
                },
            ],
        },
    )
    print(res.status_code, res.text)

Security scan

1 finding

Charges more than its listed price in payment
Listed at $0.005, charges $0.007

Recent checks

When	Result	HTTP	Time	Price
2 h ago	Timed out	-	-	-
7 h ago	Passed	402	142 ms	$0.007
12 h ago	Passed	402	139 ms	$0.007
17 h ago	Passed	402	163 ms	$0.007
21 h ago	Passed	402	262 ms	$0.007

Show 10 older checks

26 h ago	Passed	402	161 ms	$0.007
30 h ago	Passed	402	150 ms	$0.007
35 h ago	Passed	402	461 ms	$0.007
39 h ago	Passed	402	148 ms	$0.007
43 h ago	Passed	402	161 ms	$0.007
47 h ago	Passed	402	157 ms	$0.007
2 days ago	Passed	402	595 ms	$0.007
2 days ago	Passed	402	256 ms	$0.007
3 days ago	Passed	402	153 ms	$0.007
3 days ago	Passed	402	324 ms	$0.007

History

11 Oct 2026	Price changed from $0.005 to $0.007

Trust score 69/ 100

Availability (30-day uptime)		29 / 30
Valid x402 challenge		15 / 15
Response time		10 / 10
Real paying agents (30 days)		5 / 15
Charges what it lists		0 / 10
Security scan		10 / 10
Verified owner		0 / 10

How the score works

Payment terms

Price: $0.007 per call
Listed at: $0.005 (charges more)
Token: USDC
Networks: Base
Pays to: 0x836B…9Ee2

Real usage

Paying agents: 2 in 30 days
Paid calls: 5 in 30 days
Last paid call: 4 days ago

Source: x402 Bazaar settlement data.

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Trust score

[![ToolVet trust score](https://toolvet.app/badge/calc-ohfrs.svg)](https://toolvet.app/s/calc-ohfrs)