Liver · LIVE

FNI

Compute the Tavaglione 2023 fibrotic NASH index (FNI) from AST, HbA1c, and HDL cholesterol as a score for fibrotic nonalcoholic steatohepatitis.

LIVE $0.005 USDC GET /api/calc/fni

Markdown: /docs/fni.md · Canonical: https://magentlab.com/docs/fni

Not a medical device. Not a diagnosis, dose, or listing recommendation.

What it computes

Compute the Tavaglione 2023 fibrotic NASH index (FNI) from AST, HbA1c, and HDL cholesterol as a score for fibrotic nonalcoholic steatohepatitis.

When to use

When an agent needs published Tavaglione 2023 FNI arithmetic and must not invent FIB-4, NAFLD fibrosis, SAFE, or BARD cutoffs or a biopsy result.

When not to use

Not a medical device. Not a diagnosis and not a biopsy. FNI bands are published rule-out and rule-in cut-points, not histology.
Tavaglione 2023 FNI only. Not FIB-4, not the NAFLD fibrosis score, not SAFE, and not BARD.
HDL must be exactly one of hdl_mg_dl (5-150) or hdl_mmol_l (0.1-3.9). mmol/L converts as mg/dL = mmol/L * 38.67. magent does not assay AST, HbA1c, or HDL.

Formula

FNI = e^x / (1+e^x) where x = -10.33 + 2.54*ln(AST U/L) + 3.86*ln(HbA1c %) - 1.66*ln(HDL mg/dL) (natural log)

Citation

Title: Development and Validation of a Score for Fibrotic Nonalcoholic Steatohepatitis
Authors: Tavaglione F, Jamialahmadi O, De Vincentis A, et al.
Source: Clin Gastroenterol Hepatol. 2023;21(6):1523-1532.e1
DOI: 10.1016/j.cgh.2022.03.044

Worked example

AST 40 U/L, HbA1c 5.5%, HDL 50 mg/dL

Given: a1c_percent=5.5ast_u_l=40hdl_mg_dl=50

x = -10.33 + 2.54*ln(40) + 3.86*ln(5.5) - 1.66*ln(50) = -0.8739
FNI = e^x / (1+e^x) = 0.2944
0.10 < 0.2944 < 0.33 → fni_band gt_0_10_lt_0_33

Also searched as

fibrotic NASH index
FNI score
Tavaglione FNI
fibrotic nonalcoholic steatohepatitis
NASH AST HbA1c HDL score
fibrotic NASH
FNI liver score

Try

Opens the live endpoint. Unpaid browser requests show the paywall; agents should send Accept: application/json.

/api/calc/fni?ast_u_l=40&a1c_percent=5.5&hdl_mg_dl=50

Full URL: https://api.magentlab.com/api/calc/fni?ast_u_l=40&a1c_percent=5.5&hdl_mg_dl=50

Call

Expect HTTP 402 until you retry with PAYMENT-SIGNATURE. Incomplete query params return HTTP 400 before any quote or charge.

curl -i -H "Accept: application/json" "https://api.magentlab.com/api/calc/fni?ast_u_l=40&a1c_percent=5.5&hdl_mg_dl=50"

Parameters

Name	Type	Required	Description
`ast_u_l`	number	required	Aspartate aminotransferase in U/L (1-10000).
`a1c_percent`	number	required	HbA1c in percent (4-15). magent does not convert from eAG.
`hdl_mg_dl`	number	optional	HDL cholesterol in mg/dL (5-150). Provide this or hdl_mmol_l, not both. Used in the natural-log term.
`hdl_mmol_l`	number	optional	HDL cholesterol in mmol/L (0.1-3.9). Converted as mg/dL = mmol/L * 38.67. Provide this or hdl_mg_dl, not both.

Bulk (POST)

POST the same path with a JSON items array. The first item is the GET unit; each additional item is $0.002. Invalid items return HTTP 400 before settlement.

POST /api/calc/fni Max 25 unit_amount + extra_item_amount * (n - 1) extra $0.002 PREVIEW

1 to 25 items. Each item uses the same keys as the GET query parameters.
POST of 1 item costs the same as GET. Lists longer than 25: chunk into multiple POSTs. Extra items still execute; do not pad dummy rows.
The first invalid item fails the whole request (index in the 400 JSON). You are not charged.
HTTP 200 is {count, path, items}. Each items[i] is the GET 200 body for that row.
Catalog misses (empty matches, found=false) stay paid 200s inside that slot.
x402 resource URL is this path plus n and body_sha256. Browsers that prefer text/html get the same paywall as GET; Pay retries POST with the same items.

Example request (fixture)

{
  "items": [
    {
      "a1c_percent": "5.5",
      "ast_u_l": "40",
      "hdl_mg_dl": "50"
    },
    {
      "a1c_percent": "5.5",
      "ast_u_l": "40",
      "hdl_mg_dl": "50"
    }
  ]
}

Open bulk paywall →

Opens a two-item fixture on the API host. Unpaid browsers get the same MetaMask paywall as GET; Pay retries POST with those items.

Example 200 (fixture)

{
  "count": 2,
  "path": "/api/calc/fni",
  "items": [
    {
      "x": -0.8739,
      "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.",
      "citation": {
        "authors": "Tavaglione F, Jamialahmadi O, De Vincentis A, et al.",
        "doi": "10.1016/j.cgh.2022.03.044",
        "id": "tavaglione-2023",
        "pmid": "35421583",
        "source": "Clin Gastroenterol Hepatol. 2023;21(6):1523-1532.e1",
        "title": "Development and Validation of a Score for Fibrotic Nonalcoholic Steatohepatitis"
      },
      "formula": "fni",
      "formula_expression": "FNI = e^x / (1+e^x) where x = -10.33 + 2.54*ln(AST U/L) + 3.86*ln(HbA1c %) - 1.66*ln(HDL mg/dL) (natural log)",
      "ast_u_l": 40.0,
      "a1c_percent": 5.5,
      "fni": 0.2944,
      "fni_band": "gt_0_10_lt_0_33",
      "hdl_mg_dl": 50.0,
      "hdl_unit": "mg_dl"
    },
    {
      "x": -0.8739,
      "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.",
      "citation": {
        "authors": "Tavaglione F, Jamialahmadi O, De Vincentis A, et al.",
        "doi": "10.1016/j.cgh.2022.03.044",
        "id": "tavaglione-2023",
        "pmid": "35421583",
        "source": "Clin Gastroenterol Hepatol. 2023;21(6):1523-1532.e1",
        "title": "Development and Validation of a Score for Fibrotic Nonalcoholic Steatohepatitis"
      },
      "formula": "fni",
      "formula_expression": "FNI = e^x / (1+e^x) where x = -10.33 + 2.54*ln(AST U/L) + 3.86*ln(HbA1c %) - 1.66*ln(HDL mg/dL) (natural log)",
      "ast_u_l": 40.0,
      "a1c_percent": 5.5,
      "fni": 0.2944,
      "fni_band": "gt_0_10_lt_0_33",
      "hdl_mg_dl": 50.0,
      "hdl_unit": "mg_dl"
    }
  ]
}

Response

Field	Type	Description
`formula`	string	fni
`formula_expression`	string	Exact Tavaglione 2023 expression (natural log; HDL in mg/dL)
`ast_u_l`	number	AST in U/L
`a1c_percent`	number	HbA1c in percent
`hdl_mg_dl`	number	HDL cholesterol used in mg/dL (after mmol/L conversion when supplied)
`hdl_unit`	string	Caller HDL unit used: mg_dl or mmol_l
`x`	number	Linear predictor x, 4 decimals
`fni`	number	FNI probability, 4 decimals
`fni_band`	string	Published Tavaglione 2023 cut-points on the rounded FNI: lte_0_10 (rule-out; FNI ≤ 0.10), gt_0_10_lt_0_33 (indeterminate; 0.10 < FNI < 0.33), gte_0_33 (rule-in; FNI ≥ 0.33). Not a biopsy.
`citation`	object	Tavaglione Clin Gastroenterol Hepatol 2023 citation
`disclaimer`	string	Not-a-device notice

Example JSON

Machine form of the same example. Frozen fixture. Not a live lookup.

{
  "x": -0.8739,
  "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.",
  "citation": {
    "authors": "Tavaglione F, Jamialahmadi O, De Vincentis A, et al.",
    "doi": "10.1016/j.cgh.2022.03.044",
    "id": "tavaglione-2023",
    "pmid": "35421583",
    "source": "Clin Gastroenterol Hepatol. 2023;21(6):1523-1532.e1",
    "title": "Development and Validation of a Score for Fibrotic Nonalcoholic Steatohepatitis"
  },
  "formula": "fni",
  "formula_expression": "FNI = e^x / (1+e^x) where x = -10.33 + 2.54*ln(AST U/L) + 3.86*ln(HbA1c %) - 1.66*ln(HDL mg/dL) (natural log)",
  "ast_u_l": 40.0,
  "a1c_percent": 5.5,
  "fni": 0.2944,
  "fni_band": "gt_0_10_lt_0_33",
  "hdl_mg_dl": 50.0,
  "hdl_unit": "mg_dl"
}

Client errors (HTTP 400)

Invalid params return 400 without charge. Shared HTTP 402 and 503 meanings: Payments.

HTTP	Code	When
400	`invalid_ast`	ast_u_l must be a number from 1 to 10000 Returned before settlement; you are not charged.
400	`invalid_a1c`	a1c_percent must be a number from 4 to 15 Returned before settlement; you are not charged.
400	`invalid_hdl`	hdl_mg_dl must be a number from 5 to 150, or hdl_mmol_l from 0.1 to 3.9, not both. Returned before settlement; you are not charged.
400	`invalid_items`	POST body must be a JSON object with only an items array Returned before settlement; you are not charged.
400	`invalid_item_count`	items must be an array of 1 to 25 objects Returned before settlement; you are not charged.
400	`invalid_item`	each items entry must be a JSON object Returned before settlement; you are not charged.

Related tools

FIB-4 — Compute the FIB-4 fibrosis index from age, AST, ALT, and platelets.
NAFLD fibrosis score — Compute the Angulo 2007 NAFLD fibrosis score from age, BMI, IFG/diabetes, AST, ALT, platelets, and albumin.
SAFE score — Compute the Sripongpun 2023 steatosis-associated fibrosis estimator (SAFE) from age, caller-supplied BMI, diabetes, AST, ALT, globulin in g/dL, and platelets.
BARD — Sum the Harrison 2008 BARD score (BMI ≥28, AST/ALT ≥0.8, diabetes) and return low (0–1) or high (2–4).

Payment

Unpaid requests return HTTP 402 even if query parameters or POST items are missing or invalid, so CDP and agents can index the path. After a PAYMENT-SIGNATURE, invalid params return HTTP 400 JSON before settlement. magent does not charge. Fix the params, then request a new 402 quote for that complete URL. Catalog misses (empty matches, found=false) are valid paid 200s. Unpaid valid requests return HTTP 402 with a base64 PAYMENT-REQUIRED header. HTTP 503 is not a new quote: retry the same PAYMENT-SIGNATURE. Full handshake and shared payment errors: Payments. Stdio MCP: /docs/mcp.

Guarantees

HTTP 402 is unpaid, including a missing query. After PAYMENT-SIGNATURE, invalid parameters return HTTP 400 before settlement. You are not charged. HTTP 402 never includes the tool JSON.
exact: settlement finishes before the tool (paymentFlow upfront). batch-settlement: verify/deposit before the tool; chargedCumulativeAmount commits after HTTP 2xx. Uncertain or failed settlement fails closed (HTTP 503). Retry the same PAYMENT-SIGNATURE.
HTTP 402 is unpaid only. Do not sign a second authorization because of a 503.
Execution is timeout-bounded and concurrency-capped.
Calculator inputs are stored encrypted for allowlisted operators (Magent Console). They are not in public logs, SSH lookups, catalog, or rollups. Request logs store path without query.