Liver · LIVE
NAFLD fibrosis score
Compute the Angulo 2007 NAFLD fibrosis score from age, BMI, IFG/diabetes, AST, ALT, platelets, and albumin.
Markdown: /docs/nafld-fibrosis.md · Canonical: https://magentlab.com/docs/nafld-fibrosis
Not a medical device. Not a diagnosis, dose, or listing recommendation.
What it computes
Compute the Angulo 2007 NAFLD fibrosis score from age, BMI, IFG/diabetes, AST, ALT, platelets, and albumin.
When to use
When an agent needs published NAFLD fibrosis-score arithmetic and must not invent FIB-4 cutoffs or a biopsy result.
When not to use
- Not a diagnosis and not a biopsy. Angulo bands are published cut-points, not histology.
- BMI is caller-supplied. magent does not compute BMI from height and weight in this tool.
- Angulo 2007 only. Not FIB-4, not APRI, and not the BARD score.
Formula
NFS = -1.675 + 0.037*age + 0.094*BMI + 1.13*IFG/diabetes + 0.99*(AST/ALT) - 0.013*platelets - 0.66*albumin
Citation
- Title
- The NAFLD fibrosis score: a noninvasive system that identifies liver fibrosis in patients with NAFLD
- Authors
- Angulo P, Hui JM, Marchesini G, et al.
- Source
- Hepatology. 2007;45(4):846-854
Worked example
Age 50, BMI 30, IFG, AST/ALT 1, platelets 200, albumin 4
Given:
age=50albumin_g_dl=4alt_u_l=40ast_u_l=40bmi_kg_m2=30ifg_or_diabetes=trueplatelets_10e9_l=200
- IFG/diabetes = 1; AST/ALT = 40/40 = 1
- NFS = -1.675 + 0.037*50 + 0.094*30 + 1.13*1 + 0.99*1 - 0.013*200 - 0.66*4 = -0.125
- Band indeterminate (-1.455 to 0.676)
Also searched as
- NAFLD fibrosis score
- NFS Angulo
- nonalcoholic fatty liver fibrosis
- Angulo 2007
- NAFLD score
- liver fibrosis NAFLD
Try
Opens the live endpoint. Unpaid browser requests show the paywall; agents should send Accept: application/json.
Full URL: https://api.magentlab.com/api/calc/nafld_fibrosis?age=50&bmi_kg_m2=30&ifg_or_diabetes=true&ast_u_l=40&alt_u_l=40&platelets_10e9_l=200&albumin_g_dl=4
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/nafld_fibrosis?age=50&bmi_kg_m2=30&ifg_or_diabetes=true&ast_u_l=40&alt_u_l=40&platelets_10e9_l=200&albumin_g_dl=4"
Parameters
| Name | Type | Required | Description |
|---|---|---|---|
age |
integer | required | Age in years (18-120). |
bmi_kg_m2 |
number | required | Body-mass index in kg/m^2 (10-80). Caller-supplied; magent does not compute BMI. |
ifg_or_diabetes |
boolean | required | Impaired fasting glucose or diabetes as assigned by the caller (Angulo 2007 IFG/diabetes term). true or false. |
ast_u_l |
number | required | Aspartate aminotransferase in U/L (1-10000). |
alt_u_l |
number | required | Alanine aminotransferase in U/L (1-10000). |
platelets_10e9_l |
number | required | Platelet count in 10^9/L (1-2000). |
albumin_g_dl |
number | optional | Albumin in g/dL (1-6). Provide albumin_g_dl or albumin_g_l, not both. |
albumin_g_l |
number | optional | Albumin in g/L (10-60). Converted as g/dL = g/L / 10. |
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.
- 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": [
{
"age": "50",
"albumin_g_dl": "4",
"alt_u_l": "40",
"ast_u_l": "40",
"bmi_kg_m2": "30",
"ifg_or_diabetes": "true",
"platelets_10e9_l": "200"
},
{
"age": "50",
"albumin_g_dl": "4",
"alt_u_l": "40",
"ast_u_l": "40",
"bmi_kg_m2": "30",
"ifg_or_diabetes": "true",
"platelets_10e9_l": "200"
}
]
}
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/nafld_fibrosis",
"items": [
{
"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": "Angulo P, Hui JM, Marchesini G, et al.",
"doi": "10.1002/hep.21496",
"id": "angulo-2007",
"source": "Hepatology. 2007;45(4):846-854",
"title": "The NAFLD fibrosis score: a noninvasive system that identifies liver fibrosis in patients with NAFLD"
},
"formula": "nafld_fibrosis",
"formula_expression": "NFS = -1.675 + 0.037*age + 0.094*BMI + 1.13*IFG/diabetes + 0.99*(AST/ALT) - 0.013*platelets - 0.66*albumin",
"albumin_g_dl": 4.0,
"age_years": 50,
"ast_u_l": 40.0,
"platelets_10e9_l": 200.0,
"alt_u_l": 40.0,
"angulo_band": "indeterminate",
"ast_alt_ratio": 1.0,
"bmi_kg_m2": 30.0,
"ifg_or_diabetes": true,
"nfs": -0.125
},
{
"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": "Angulo P, Hui JM, Marchesini G, et al.",
"doi": "10.1002/hep.21496",
"id": "angulo-2007",
"source": "Hepatology. 2007;45(4):846-854",
"title": "The NAFLD fibrosis score: a noninvasive system that identifies liver fibrosis in patients with NAFLD"
},
"formula": "nafld_fibrosis",
"formula_expression": "NFS = -1.675 + 0.037*age + 0.094*BMI + 1.13*IFG/diabetes + 0.99*(AST/ALT) - 0.013*platelets - 0.66*albumin",
"albumin_g_dl": 4.0,
"age_years": 50,
"ast_u_l": 40.0,
"platelets_10e9_l": 200.0,
"alt_u_l": 40.0,
"angulo_band": "indeterminate",
"ast_alt_ratio": 1.0,
"bmi_kg_m2": 30.0,
"ifg_or_diabetes": true,
"nfs": -0.125
}
]
}
Response
| Field | Type | Description |
|---|---|---|
formula |
string | nafld_fibrosis |
formula_expression |
string | Exact Angulo 2007 expression |
age_years |
integer | Age in years used |
bmi_kg_m2 |
number | Caller-supplied BMI in kg/m^2 |
ifg_or_diabetes |
boolean | IFG or diabetes flag used |
ast_u_l |
number | AST in U/L |
alt_u_l |
number | ALT in U/L |
ast_alt_ratio |
number | AST/ALT ratio, 4 decimals |
platelets_10e9_l |
number | Platelets in 10^9/L |
albumin_g_dl |
number | Albumin in g/dL |
nfs |
number | NAFLD fibrosis score, 3 decimals |
angulo_band |
string | Published Angulo 2007 cut-points: low (<-1.455), indeterminate (-1.455 to 0.676), high (>0.676). Not a diagnosis. |
citation |
object | Angulo Hepatology 2007 citation |
disclaimer |
string | Not-a-device notice |
Example JSON
Machine form of the same example. Frozen fixture. Not a live lookup.
{
"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": "Angulo P, Hui JM, Marchesini G, et al.",
"doi": "10.1002/hep.21496",
"id": "angulo-2007",
"source": "Hepatology. 2007;45(4):846-854",
"title": "The NAFLD fibrosis score: a noninvasive system that identifies liver fibrosis in patients with NAFLD"
},
"formula": "nafld_fibrosis",
"formula_expression": "NFS = -1.675 + 0.037*age + 0.094*BMI + 1.13*IFG/diabetes + 0.99*(AST/ALT) - 0.013*platelets - 0.66*albumin",
"albumin_g_dl": 4.0,
"age_years": 50,
"ast_u_l": 40.0,
"platelets_10e9_l": 200.0,
"alt_u_l": 40.0,
"angulo_band": "indeterminate",
"ast_alt_ratio": 1.0,
"bmi_kg_m2": 30.0,
"ifg_or_diabetes": true,
"nfs": -0.125
}
Client errors (HTTP 400)
Invalid params return 400 without charge. Shared HTTP 402 and 503 meanings: Payments.
| HTTP | Code | When |
|---|---|---|
| 400 | invalid_age |
age must be an integer from 18 to 120 Returned before settlement; you are not charged. |
| 400 | invalid_bmi_kg_m2 |
bmi_kg_m2 must be a number from 10 to 80. Returned before settlement; you are not charged. |
| 400 | invalid_flag |
boolean clinical flags must be true or false Returned before settlement; you are not charged. |
| 400 | invalid_ast |
ast_u_l must be a number from 1 to 10000 Returned before settlement; you are not charged. |
| 400 | invalid_alt |
alt_u_l must be a number from 1 to 10000 Returned before settlement; you are not charged. |
| 400 | invalid_platelets |
platelets_10e9_l must be a number from 1 to 2000 Returned before settlement; you are not charged. |
| 400 | invalid_albumin |
albumin_g_dl (1-6) or albumin_g_l (10-60) is required 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.
- APRI — Compute the AST to platelet ratio index (APRI) from AST, laboratory AST ULN, and platelet count.
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.
- 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.