# NAFLD fibrosis score NAFLD fibrosis score Status: LIVE Price: $0.005 USDC `GET /api/calc/nafld_fibrosis` HTML: https://magentlab.com/docs/nafld-fibrosis Markdown: https://magentlab.com/docs/nafld-fibrosis.md 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 [The NAFLD fibrosis score: a noninvasive system that identifies liver fibrosis in patients with NAFLD](https://doi.org/10.1002/hep.21496) Angulo P, Hui JM, Marchesini G, et al. Hepatology. 2007;45(4):846-854 DOI: [10.1002/hep.21496](https://doi.org/10.1002/hep.21496) ## Worked example ### Age 50, BMI 30, IFG, AST/ALT 1, platelets 200, albumin 4 Given: `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` 1. IFG/diabetes = 1; AST/ALT = 40/40 = 1 2. NFS = -1.675 + 0.037*50 + 0.094*30 + 1.13*1 + 0.99*1 - 0.013*200 - 0.66*4 = -0.125 3. 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 ## Parameters - `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. Method: `POST /api/calc/nafld_fibrosis` Max items: 25 Price: unit_amount + extra_item_amount * (n - 1) (unit 5000 atomic, extra 2000 atomic) Status: 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: ```json { "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" } ] } ``` Human paywall (two-item fixture): https://api.magentlab.com/paywall/bulk/nafld-fibrosis Example 200: ```json { "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", "age_years": 50, "albumin_g_dl": 4.0, "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", "age_years": 50, "albumin_g_dl": 4.0, "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 fields - `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 Frozen fixture. Not a live lookup. ```json { "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", "age_years": 50, "albumin_g_dl": 4.0, "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 } ``` ## Errors - HTTP 400 `invalid_age`: age must be an integer from 18 to 120 Returned before settlement; you are not charged. - HTTP 400 `invalid_bmi_kg_m2`: bmi_kg_m2 must be a number from 10 to 80. Returned before settlement; you are not charged. - HTTP 400 `invalid_flag`: boolean clinical flags must be true or false Returned before settlement; you are not charged. - HTTP 400 `invalid_ast`: ast_u_l must be a number from 1 to 10000 Returned before settlement; you are not charged. - HTTP 400 `invalid_alt`: alt_u_l must be a number from 1 to 10000 Returned before settlement; you are not charged. - HTTP 400 `invalid_platelets`: platelets_10e9_l must be a number from 1 to 2000 Returned before settlement; you are not charged. - HTTP 400 `invalid_albumin`: albumin_g_dl (1-6) or albumin_g_l (10-60) is required Returned before settlement; you are not charged. - HTTP 400 `invalid_items`: POST body must be a JSON object with only an items array Returned before settlement; you are not charged. - HTTP 400 `invalid_item_count`: items must be an array of 1 to 25 objects Returned before settlement; you are not charged. - HTTP 400 `invalid_item`: each items entry must be a JSON object Returned before settlement; you are not charged. Shared HTTP 402 and 503: https://magentlab.com/docs/payments ## Related tools - [FIB-4](https://magentlab.com/docs/fib4) — Compute the FIB-4 fibrosis index from age, AST, ALT, and platelets. - [APRI](https://magentlab.com/docs/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. - GET the tool with Accept: application/json (do not send Accept: text/html unless you want the human paywall). - HTTP 402 means you have not paid. Decode the base64 PAYMENT-REQUIRED header. HTTP 503 is not a new quote. - Sign accepts[0] (exact, EIP-3009) with validBefore = now + maxTimeoutSeconds (600 seconds), or accepts[1] (batch-settlement deposit/voucher) on product GET. Ping and POST {items} stay exact. Magent retries transient facilitator 429/5xx before answering. - Retry the same URL with PAYMENT-SIGNATURE (base64 JSON echoing accepted, payload, and extensions when present). - Success is HTTP 200 JSON plus PAYMENT-RESPONSE. exact settles before the tool. batch-settlement verifies (and deposit-settles) before the tool and commits the charge after HTTP 2xx. HTTP 503: retry the same PAYMENT-SIGNATURE. Mint a new exact nonce only after a new HTTP 402. - offered `exact` on eip155:8453: Fixed-price USDC on Base. The buyer authorizes the advertised amount (EIP-3009). magent settles before the tool runs (paymentFlow upfront). extra.assetTransferMethod=eip3009 extra.paymentFlow=upfront. - offered `batch-settlement` on eip155:8453: Payment-channel vouchers claimed later in batches. Exact stays accepts[0]. Same-path POST {items} is still exact. extra.assetTransferMethod=eip3009 extra.paymentFlow=authorization. - not offered `upto`: Not offered. Usage-based: buyer authorizes a ceiling, seller settles the actual amount after work. Reserved for a future metered tool. Not for current calculators or code search. Same-path POST {items} is still scheme exact: one EIP-3009 authorization for GET unit plus $0.002 per extra item. That is not x402 batch-settlement (payment channels / vouchers). Shared HTTP 402 and 503 table: https://magentlab.com/docs/payments Stdio MCP (one process per host): https://magentlab.com/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.