69trust / 100

Calc Possum

x402 APIPassing, checked 4 h ago

Copeland 1991 POSSUM surgical audit: 12 physiologic and 6 operative 1/2/4/8 items (age has no 8; ECG has no 2). Returns physiologic_score, operative_score, and estimated morbidity and mortality percents from the unrounded Copeland logits. Not P-POSSUM (Whiteley), not a diagnosis, not operative consent. magent does not examine the patient.

POST

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

Price: $0.007; per call in USDC
Uptime: 97.1%; last 30 days
Response time: 259 ms; 620 ms slowest 5%
Last check: Passed; 4 h ago, next any minute now

Run a free test call How to call it

Reliability

All checks passedSome failedAll failedNot checked

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

How to call it

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

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/possum
content-type: application/json

{
  "items": [
    {
      "age_years": 50,
      "blood_loss_ml": 50,
      "cardiac": "no_failure",
      "ecg": "normal",
      "gcs": 15,
      "hemoglobin_g_dl": 14,
      "malignancy": "none",
      "mode_of_surgery": "elective",
      "multiple_procedures": "one",
      "operative_severity": "minor",
      "peritoneal_soiling": "none",
      "potassium_mmol_l": 4,
      "pulse": 70,
      "respiratory": "no_dyspnea",
      "sodium_mmol_l": 140,
      "systolic_bp_mm_hg": 120,
      "urea_mmol_l": 5,
      "wbc_k_ul": 8
    },
    {
      "age_years": 50,
      "blood_loss_ml": 50,
      "cardiac": "no_failure",
      "ecg": "normal",
      "gcs": 15,
      "hemoglobin_g_dl": 14,
      "malignancy": "none",
      "mode_of_surgery": "elective",
      "multiple_procedures": "one",
      "operative_severity": "minor",
      "peritoneal_soiling": "none",
      "potassium_mmol_l": 4,
      "pulse": 70,
      "respiratory": "no_dyspnea",
      "sodium_mmol_l": 140,
      "systolic_bp_mm_hg": 120,
      "urea_mmol_l": 5,
      "wbc_k_ul": 8
    }
  ]
}

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, 264 lines

{
  "count": 2,
  "items": [
    {
      "citation": {
        "authors": "Copeland GP, Jones D, Walters M",
        "doi": "10.1002/bjs.1800780327",
        "id": "copeland-1991",
        "pmid": "2021856",
        "source": "Br J Surg. 1991;78(3):355-360",
        "title": "POSSUM: a scoring system for surgical audit"
      },
      "components": [
        {
          "factor": "age_years",
          "points": 1,
          "present": true,
          "value": 50
        },
        {
          "factor": "cardiac",
          "points": 1,
          "present": true,
          "value": "no_failure"
        },
        {
          "factor": "respiratory",
          "points": 1,
          "present": true,
          "value": "no_dyspnea"
        },
        {
          "factor": "systolic_bp_mm_hg",
          "points": 1,
          "present": true,
          "value": 120
        },
        {
          "factor": "pulse",
          "points": 1,
          "present": true,
          "value": 70
        },
        {
          "factor": "gcs",
          "points": 1,
          "present": true,
          "value": 15
        },
        {
          "factor": "hemoglobin_g_dl",
          "points": 1,
          "present": true,
          "value": 14
        },
        {
          "factor": "wbc_k_ul",
          "points": 1,
          "present": true,
          "value": 8
        },
        {
          "factor": "urea_mmol_l",
          "points": 1,
          "present": true,
          "value": 5
        },
        {
          "factor": "sodium_mmol_l",
          "points": 1,
          "present": true,
          "value": 140
        },
        {
          "factor": "potassium_mmol_l",
          "points": 1,
          "present": true,
          "value": 4
        },
        {
          "factor": "ecg",
          "points": 1,
          "present": true,
          "value": "normal"
        },
        {
          "factor": "operative_severity",
          "points": 1,
          "present": true,
          "value": "minor"
        },
        {
          "factor": "multiple_procedures",
          "points": 1,
          "present": true,
          "value": "one"
        },
        {
          "factor": "blood_loss_ml",
          "points": 1,
          "present": true,
          "value": 50
        },
        {
          "factor": "peritoneal_soiling",
          "points": 1,
          "present": true,
          "value": "none"
        },
        {
          "factor": "malignancy",
          "points": 1,
          "present": true,
          "value": "none"
        },
        {
          "factor": "mode_of_surgery",
          "points": 1,
          "present": true,
          "value": "elective"
        }
      ],
      "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.",
      "estimated_morbidity_percent": 5.47,
      "estimated_mortality_percent": 1.08,
      "formula": "possum",
      "formula_expression": "physiologic_score = sum of 12 Copeland 1991 Table 1 items (1/2/4/8; age has no 8, ECG has no 2); operative_score = sum of 6 Table 2 items (1/2/4/8; multiple_procedures and mode_of_surgery have no 2); ln[R/(1-R)] morbidity = -5.91 + 0.16*physiologic_score + 0.19*operative_score; ln[R/(1-R)] mortality = -7.04 + 0.13*physiologic_score + 0.16*operative_score; estimated_morbidity_percent and estimated_mortality_percent = 100 * exp(logit)/(1+exp(logit)) from the unrounded logit",
      "morbidity_logit": -2.85,
      "mortality_logit": -4.52,
      "operative_score": 6,
      "physiologic_score": 12
    },
    {
      "citation": {
        "authors": "Copeland GP, Jones D, Walters M",
        "doi": "10.1002/bjs.1800780327",
        "id": "copeland-1991",
        "pmid": "2021856",
        "source": "Br J Surg. 1991;78(3):355-360",
        "title": "POSSUM: a scoring system for surgical audit"
      },
      "components": [
        {
          "factor": "age_years",
          "points": 1,
          "present": true,
          "value": 50
        },
        {
          "factor": "cardiac",
          "points": 1,
          "present": true,
          "value": "no_failure"
        },
        {
          "factor": "respiratory",
          "points": 1,
          "present": true,
          "value": "no_dyspnea"
        },
        {
          "factor": "systolic_bp_mm_hg",
          "points": 1,
          "present": true,
          "value": 120
        },
        {
          "factor": "pulse",
          "points": 1,
          "present": true,
          "value": 70
        },
        {
          "factor": "gcs",
          "points": 1,
          "present": true,
          "value": 15
        },
        {
          "factor": "hemoglobin_g_dl",
          "points": 1,
          "present": true,
          "value": 14
        },
        {
          "factor": "wbc_k_ul",
          "points": 1,
          "present": true,
          "value": 8
        },
        {
          "factor": "urea_mmol_l",
          "points": 1,
          "present": true,
          "value": 5
        },
        {
          "factor": "sodium_mmol_l",
          "points": 1,
          "present": true,
          "value": 140
        },
        {
          "factor": "potassium_mmol_l",
          "points": 1,
          "present": true,
          "value": 4
        },
        {
          "factor": "ecg",
          "points": 1,
          "present": true,
          "value": "normal"
        },
        {
          "factor": "operative_severity",
          "points": 1,
          "present": true,
          "value": "minor"
        },
        {
          "factor": "multiple_procedures",
          "points": 1,
          "present": true,
          "value": "one"
        },
        {
          "factor": "blood_loss_ml",
          "points": 1,
          "present": true,
          "value": 50
        },
        {
          "factor": "peritoneal_soiling",
          "points": 1,
          "present": true,
          "value": "none"
        },
        {
          "factor": "malignancy",
          "points": 1,
          "present": true,
          "value": "none"
        },
        {
          "factor": "mode_of_surgery",
          "points": 1,
          "present": true,
          "value": "elective"
        }
      ],
      "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.",
      "estimated_morbidity_percent": 5.47,
      "estimated_mortality_percent": 1.08,
      "formula": "possum",
      "formula_expression": "physiologic_score = sum of 12 Copeland 1991 Table 1 items (1/2/4/8; age has no 8, ECG has no 2); operative_score = sum of 6 Table 2 items (1/2/4/8; multiple_procedures and mode_of_surgery have no 2); ln[R/(1-R)] morbidity = -5.91 + 0.16*physiologic_score + 0.19*operative_score; ln[R/(1-R)] mortality = -7.04 + 0.13*physiologic_score + 0.16*operative_score; estimated_morbidity_percent and estimated_mortality_percent = 100 * exp(logit)/(1+exp(logit)) from the unrounded logit",
      "morbidity_logit": -2.85,
      "mortality_logit": -4.52,
      "operative_score": 6,
      "physiologic_score": 12
    }
  ],
  "path": "/api/calc/possum"
}

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/possum' \
  -H 'content-type: application/json' \
  --data-raw '{"items":[{"age_years":50,"blood_loss_ml":50,"cardiac":"no_failure","ecg":"normal","gcs":15,"hemoglobin_g_dl":14,"malignancy":"none","mode_of_surgery":"elective","multiple_procedures":"one","operative_severity":"minor","peritoneal_soiling":"none","potassium_mmol_l":4,"pulse":70,"respiratory":"no_dyspnea","sodium_mmol_l":140,"systolic_bp_mm_hg":120,"urea_mmol_l":5,"wbc_k_ul":8},{"age_years":50,"blood_loss_ml":50,"cardiac":"no_failure","ecg":"normal","gcs":15,"hemoglobin_g_dl":14,"malignancy":"none","mode_of_surgery":"elective","multiple_procedures":"one","operative_severity":"minor","peritoneal_soiling":"none","potassium_mmol_l":4,"pulse":70,"respiratory":"no_dyspnea","sodium_mmol_l":140,"systolic_bp_mm_hg":120,"urea_mmol_l":5,"wbc_k_ul":8}]}'

# 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/possum' \
  -H 'content-type: application/json' \
  --data-raw '{"items":[{"age_years":50,"blood_loss_ml":50,"cardiac":"no_failure","ecg":"normal","gcs":15,"hemoglobin_g_dl":14,"malignancy":"none","mode_of_surgery":"elective","multiple_procedures":"one","operative_severity":"minor","peritoneal_soiling":"none","potassium_mmol_l":4,"pulse":70,"respiratory":"no_dyspnea","sodium_mmol_l":140,"systolic_bp_mm_hg":120,"urea_mmol_l":5,"wbc_k_ul":8},{"age_years":50,"blood_loss_ml":50,"cardiac":"no_failure","ecg":"normal","gcs":15,"hemoglobin_g_dl":14,"malignancy":"none","mode_of_surgery":"elective","multiple_procedures":"one","operative_severity":"minor","peritoneal_soiling":"none","potassium_mmol_l":4,"pulse":70,"respiratory":"no_dyspnea","sodium_mmol_l":140,"systolic_bp_mm_hg":120,"urea_mmol_l":5,"wbc_k_ul":8}]}' \
  | 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%2Fpossum&method=POST
const res = await pay("https://api.magentlab.com/api/calc/possum", {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({
    "items": [
      {
        "age_years": 50,
        "blood_loss_ml": 50,
        "cardiac": "no_failure",
        "ecg": "normal",
        "gcs": 15,
        "hemoglobin_g_dl": 14,
        "malignancy": "none",
        "mode_of_surgery": "elective",
        "multiple_procedures": "one",
        "operative_severity": "minor",
        "peritoneal_soiling": "none",
        "potassium_mmol_l": 4,
        "pulse": 70,
        "respiratory": "no_dyspnea",
        "sodium_mmol_l": 140,
        "systolic_bp_mm_hg": 120,
        "urea_mmol_l": 5,
        "wbc_k_ul": 8
      },
      {
        "age_years": 50,
        "blood_loss_ml": 50,
        "cardiac": "no_failure",
        "ecg": "normal",
        "gcs": 15,
        "hemoglobin_g_dl": 14,
        "malignancy": "none",
        "mode_of_surgery": "elective",
        "multiple_procedures": "one",
        "operative_severity": "minor",
        "peritoneal_soiling": "none",
        "potassium_mmol_l": 4,
        "pulse": 70,
        "respiratory": "no_dyspnea",
        "sodium_mmol_l": 140,
        "systolic_bp_mm_hg": 120,
        "urea_mmol_l": 5,
        "wbc_k_ul": 8
      }
    ]
  }),
});
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/possum",
        json={
            "items": [
                {
                    "age_years": 50,
                    "blood_loss_ml": 50,
                    "cardiac": "no_failure",
                    "ecg": "normal",
                    "gcs": 15,
                    "hemoglobin_g_dl": 14,
                    "malignancy": "none",
                    "mode_of_surgery": "elective",
                    "multiple_procedures": "one",
                    "operative_severity": "minor",
                    "peritoneal_soiling": "none",
                    "potassium_mmol_l": 4,
                    "pulse": 70,
                    "respiratory": "no_dyspnea",
                    "sodium_mmol_l": 140,
                    "systolic_bp_mm_hg": 120,
                    "urea_mmol_l": 5,
                    "wbc_k_ul": 8,
                },
                {
                    "age_years": 50,
                    "blood_loss_ml": 50,
                    "cardiac": "no_failure",
                    "ecg": "normal",
                    "gcs": 15,
                    "hemoglobin_g_dl": 14,
                    "malignancy": "none",
                    "mode_of_surgery": "elective",
                    "multiple_procedures": "one",
                    "operative_severity": "minor",
                    "peritoneal_soiling": "none",
                    "potassium_mmol_l": 4,
                    "pulse": 70,
                    "respiratory": "no_dyspnea",
                    "sodium_mmol_l": 140,
                    "systolic_bp_mm_hg": 120,
                    "urea_mmol_l": 5,
                    "wbc_k_ul": 8,
                },
            ],
        },
    )
    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
4 h ago	Passed	402	402 ms	$0.007
9 h ago	Passed	402	296 ms	$0.007
13 h ago	Timed out	-	-	-
18 h ago	Passed	402	155 ms	$0.007
23 h ago	Passed	402	223 ms	$0.007

Show 10 older checks

27 h ago	Passed	402	223 ms	$0.007
32 h ago	Passed	402	479 ms	$0.007
36 h ago	Passed	402	385 ms	$0.007
40 h ago	Passed	402	259 ms	$0.007
44 h ago	Passed	402	168 ms	$0.007
2 days ago	Passed	402	177 ms	$0.007
2 days ago	Passed	402	180 ms	$0.007
2 days ago	Passed	402	437 ms	$0.007
3 days ago	Passed	402	233 ms	$0.007
3 days ago	Passed	402	345 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-possum.svg)](https://toolvet.app/s/calc-possum)