Calc Fib4
by magent in AI models & inference
Cited Sterling 2006 FIB-4 fibrosis index. Agents must not invent FIB-4 from model memory; pay per request with x402 USDC on Base. Deterministic published index with citation. Not a treatment recommendation.
https://api.magentlab.com/api/calc/fib4- Price
- $0.007
- per call in USDC
- Uptime
- 91.4%
- last 30 days
- Response time
- 142 ms
- 326 ms slowest 5%
- Last check
- Failed
- 40 min ago, next in 24 min
Reliability
Latest check failed 40 min ago: Timed out
Status and outage history · Atom feed · Watch with other listings
How to call it
POST https://api.magentlab.com/api/calc/fib4
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/fib4
content-type: application/json
{
"items": [
{
"age": 50,
"alt_u_l": 40,
"ast_u_l": 100,
"platelets_10e9_l": 200
},
{
"age": 50,
"alt_u_l": 40,
"ast_u_l": 100,
"platelets_10e9_l": 200
}
]
}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, 42 lines
{
"count": 2,
"items": [
{
"age_years": 50,
"alt_u_l": 40,
"ast_u_l": 100,
"citation": {
"authors": "Sterling RK, Lissen E, Clumeck N, et al.",
"doi": "10.1002/hep.21172",
"id": "sterling-2006",
"source": "Hepatology. 2006;43(6):1317-1325",
"title": "Development of a simple noninvasive index to predict significant fibrosis in patients with HIV/HCV coinfection"
},
"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.",
"fib4": 3.95,
"formula": "fib4",
"formula_expression": "FIB-4 = (age_years * AST_U_L) / (platelets_10e9_L * sqrt(ALT_U_L))",
"platelets_10e9_l": 200,
"sterling_band": "high"
},
{
"age_years": 50,
"alt_u_l": 40,
"ast_u_l": 100,
"citation": {
"authors": "Sterling RK, Lissen E, Clumeck N, et al.",
"doi": "10.1002/hep.21172",
"id": "sterling-2006",
"source": "Hepatology. 2006;43(6):1317-1325",
"title": "Development of a simple noninvasive index to predict significant fibrosis in patients with HIV/HCV coinfection"
},
"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.",
"fib4": 3.95,
"formula": "fib4",
"formula_expression": "FIB-4 = (age_years * AST_U_L) / (platelets_10e9_L * sqrt(ALT_U_L))",
"platelets_10e9_l": 200,
"sterling_band": "high"
}
],
"path": "/api/calc/fib4"
}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/fib4' \
-H 'content-type: application/json' \
--data-raw '{"items":[{"age":50,"alt_u_l":40,"ast_u_l":100,"platelets_10e9_l":200},{"age":50,"alt_u_l":40,"ast_u_l":100,"platelets_10e9_l":200}]}'
# 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/fib4' \
-H 'content-type: application/json' \
--data-raw '{"items":[{"age":50,"alt_u_l":40,"ast_u_l":100,"platelets_10e9_l":200},{"age":50,"alt_u_l":40,"ast_u_l":100,"platelets_10e9_l":200}]}' \
| grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decodeJavaScript: 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%2Ffib4&method=POST
const res = await pay("https://api.magentlab.com/api/calc/fib4", {
method: "POST",
headers: { "content-type": "application/json" },
body: JSON.stringify({
"items": [
{
"age": 50,
"alt_u_l": 40,
"ast_u_l": 100,
"platelets_10e9_l": 200
},
{
"age": 50,
"alt_u_l": 40,
"ast_u_l": 100,
"platelets_10e9_l": 200
}
]
}),
});
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/fib4",
json={
"items": [
{
"age": 50,
"alt_u_l": 40,
"ast_u_l": 100,
"platelets_10e9_l": 200,
},
{
"age": 50,
"alt_u_l": 40,
"ast_u_l": 100,
"platelets_10e9_l": 200,
},
],
},
)
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 |
|---|---|---|---|---|
| 40 min ago | Timed out | - | - | - |
| 6 h ago | Timed out | - | - | - |
| 10 h ago | Timed out | - | - | - |
| 15 h ago | Passed | 402 | 139 ms | $0.007 |
| 20 h ago | Passed | 402 | 141 ms | $0.007 |
Show 10 older checks
| 25 h ago | Passed | 402 | 436 ms | $0.007 |
| 29 h ago | Passed | 402 | 148 ms | $0.007 |
| 34 h ago | Passed | 402 | 150 ms | $0.007 |
| 38 h ago | Passed | 402 | 137 ms | $0.007 |
| 43 h ago | Passed | 402 | 228 ms | $0.007 |
| 47 h ago | Passed | 402 | 145 ms | $0.007 |
| 2 days ago | Passed | 402 | 319 ms | $0.007 |
| 2 days ago | Passed | 402 | 132 ms | $0.007 |
| 3 days ago | Passed | 402 | 136 ms | $0.007 |
| 3 days ago | Passed | 402 | 323 ms | $0.007 |
History
| 11 Oct 2026 | Price changed from $0.005 to $0.007 |