# Child–Pugh

Status: LIVE
Price: $0.005 USDC
`GET /api/calc/child_pugh`
HTML: https://magentlab.com/docs/child-pugh
Markdown: https://magentlab.com/docs/child-pugh.md

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

## What it computes

Compute the Child–Turcotte–Pugh cirrhosis severity score from bilirubin, albumin, INR, encephalopathy, and ascites.

## When to use

When an agent needs the published Child–Pugh class and must not invent points from a chart narrative.

## When not to use

- Not a transplant listing protocol and not a MELD-Na substitute.
- Encephalopathy and ascites are caller-assigned grades. magent does not examine the patient.
- Pugh 1973 scored coagulation as prothrombin time prolonged 1–4 / 4–6 / >6 seconds. This tool accepts INR <1.7 / 1.7–2.3 / >2.3 as the contemporary laboratory substitute.

## Formula

```
Child-Pugh = bilirubin + albumin + INR + encephalopathy + ascites; each 1-3; class A 5-6, B 7-9, C 10-15; max 15
```

## Citation

Transection of the oesophagus for bleeding oesophageal varices
Pugh RNH, Murray-Lyon IM, Dawson JL, Pietroni MC, Williams R
Br J Surg. 1973;60(8):646-649
DOI: [10.1002/bjs.1800600817](https://doi.org/10.1002/bjs.1800600817)

## Worked example

### All grade 1 (class A)

Given: `albumin_g_dl=4.0, ascites=none, bilirubin_mg_dl=1.0, encephalopathy=none, inr=1.2`

1. Bilirubin 1.0 → 1; albumin 4.0 → 1; INR 1.2 → 1; encephalopathy none → 1; ascites none → 1
2. Score = 5; class A


## Parameters

- `bilirubin_mg_dl` (number, optional): Total bilirubin in mg/dL (0.1-40). Provide this or bilirubin_umol_l. <2.0 scores 1; 2.0-3.0 scores 2; >3.0 scores 3.
- `bilirubin_umol_l` (number, optional): Total bilirubin in µmol/L. Converted as mg/dL = µmol/L / 17.1.
- `albumin_g_dl` (number, optional): Albumin in g/dL (1-6). Provide this or albumin_g_l. >3.5 scores 1; 2.8-3.5 scores 2; <2.8 scores 3.
- `albumin_g_l` (number, optional): Albumin in g/L. Converted as g/dL = g/L / 10.
- `inr` (number, required): INR (0.8-10). Contemporary substitute for Pugh PT-prolongation seconds. <1.70 scores 1; 1.70-2.30 scores 2; >2.30 scores 3.
- `encephalopathy` (string, required): Caller-assigned encephalopathy grade. none scores 1; grade_1_2 scores 2; grade_3_4 scores 3. magent does not examine the patient.
- `ascites` (string, required): Caller-assigned ascites. none scores 1; slight scores 2; moderate scores 3. magent does not examine the patient.

## Bulk (POST)

POST the same path with a JSON items array. Price is n times the GET unit. Invalid items return HTTP 400 before settlement.

Method: `POST /api/calc/child_pugh`
Max items: 25
Price: unit_amount * n (unit 5000 atomic)
Status: PREVIEW

- 1 to 25 items. Each item uses the same keys as the GET query parameters.
- 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": [
    {
      "albumin_g_dl": "4.0",
      "ascites": "none",
      "bilirubin_mg_dl": "1.0",
      "encephalopathy": "none",
      "inr": "1.2"
    },
    {
      "albumin_g_dl": "4.0",
      "ascites": "none",
      "bilirubin_mg_dl": "1.0",
      "encephalopathy": "none",
      "inr": "1.2"
    }
  ]
}
```

Human paywall (two-item fixture): https://api.magentlab.com/paywall/bulk/child-pugh

Example 200:

```json
{
  "count": 2,
  "path": "/api/calc/child_pugh",
  "items": [
    {
      "components": [
        {
          "value": 1.0,
          "factor": "bilirubin",
          "points": 1,
          "present": false
        },
        {
          "value": 4.0,
          "factor": "albumin",
          "points": 1,
          "present": false
        },
        {
          "value": 1.2,
          "factor": "inr",
          "points": 1,
          "present": false
        },
        {
          "value": "none",
          "factor": "encephalopathy",
          "points": 1,
          "present": false
        },
        {
          "value": "none",
          "factor": "ascites",
          "points": 1,
          "present": false
        }
      ],
      "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": "Pugh RNH, Murray-Lyon IM, Dawson JL, Pietroni MC, Williams R",
        "doi": "10.1002/bjs.1800600817",
        "id": "pugh-1973",
        "source": "Br J Surg. 1973;60(8):646-649",
        "title": "Transection of the oesophagus for bleeding oesophageal varices"
      },
      "formula": "child_pugh",
      "formula_expression": "Child-Pugh = bilirubin + albumin + INR + encephalopathy + ascites; each 1-3; class A 5-6, B 7-9, C 10-15; max 15",
      "max_score": 15,
      "score": 5,
      "albumin_g_dl": 4.0,
      "bilirubin_mg_dl": 1.0,
      "ascites": "none",
      "child_pugh_class": "A",
      "encephalopathy": "none",
      "inr": 1.2
    },
    {
      "components": [
        {
          "value": 1.0,
          "factor": "bilirubin",
          "points": 1,
          "present": false
        },
        {
          "value": 4.0,
          "factor": "albumin",
          "points": 1,
          "present": false
        },
        {
          "value": 1.2,
          "factor": "inr",
          "points": 1,
          "present": false
        },
        {
          "value": "none",
          "factor": "encephalopathy",
          "points": 1,
          "present": false
        },
        {
          "value": "none",
          "factor": "ascites",
          "points": 1,
          "present": false
        }
      ],
      "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": "Pugh RNH, Murray-Lyon IM, Dawson JL, Pietroni MC, Williams R",
        "doi": "10.1002/bjs.1800600817",
        "id": "pugh-1973",
        "source": "Br J Surg. 1973;60(8):646-649",
        "title": "Transection of the oesophagus for bleeding oesophageal varices"
      },
      "formula": "child_pugh",
      "formula_expression": "Child-Pugh = bilirubin + albumin + INR + encephalopathy + ascites; each 1-3; class A 5-6, B 7-9, C 10-15; max 15",
      "max_score": 15,
      "score": 5,
      "albumin_g_dl": 4.0,
      "bilirubin_mg_dl": 1.0,
      "ascites": "none",
      "child_pugh_class": "A",
      "encephalopathy": "none",
      "inr": 1.2
    }
  ]
}
```

## Response fields

- `formula` (string): child_pugh
- `formula_expression` (string): Exact expression used
- `score` (integer): Total points 5-15
- `max_score` (integer): Always 15
- `child_pugh_class` (string): A (5-6), B (7-9), or C (10-15)
- `bilirubin_mg_dl` (number): Normalized bilirubin in mg/dL
- `albumin_g_dl` (number): Normalized albumin in g/dL
- `inr` (number): Input INR
- `encephalopathy` (string): Caller-assigned none, grade_1_2, or grade_3_4
- `ascites` (string): Caller-assigned none, slight, or moderate
- `components` (array): Per-factor 1-3 points
- `citation` (object): Pugh 1973 citation
- `disclaimer` (string): Not-a-device notice

## Example JSON

Frozen fixture. Not a live lookup.

```json
{
  "components": [
    {
      "value": 1.0,
      "factor": "bilirubin",
      "points": 1,
      "present": false
    },
    {
      "value": 4.0,
      "factor": "albumin",
      "points": 1,
      "present": false
    },
    {
      "value": 1.2,
      "factor": "inr",
      "points": 1,
      "present": false
    },
    {
      "value": "none",
      "factor": "encephalopathy",
      "points": 1,
      "present": false
    },
    {
      "value": "none",
      "factor": "ascites",
      "points": 1,
      "present": false
    }
  ],
  "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": "Pugh RNH, Murray-Lyon IM, Dawson JL, Pietroni MC, Williams R",
    "doi": "10.1002/bjs.1800600817",
    "id": "pugh-1973",
    "source": "Br J Surg. 1973;60(8):646-649",
    "title": "Transection of the oesophagus for bleeding oesophageal varices"
  },
  "formula": "child_pugh",
  "formula_expression": "Child-Pugh = bilirubin + albumin + INR + encephalopathy + ascites; each 1-3; class A 5-6, B 7-9, C 10-15; max 15",
  "max_score": 15,
  "score": 5,
  "albumin_g_dl": 4.0,
  "bilirubin_mg_dl": 1.0,
  "ascites": "none",
  "child_pugh_class": "A",
  "encephalopathy": "none",
  "inr": 1.2
}
```

## Errors

- HTTP 400 `invalid_bilirubin`: bilirubin_mg_dl (0.1-40) or bilirubin_umol_l (2-684) is required 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_inr`: inr must be a number from 0.8 to 10 Returned before settlement; you are not charged.
- HTTP 400 `invalid_encephalopathy`: encephalopathy must be none, grade_1_2, or grade_3_4. Returned before settlement; you are not charged.
- HTTP 400 `invalid_ascites`: ascites must be none, slight, or moderate. 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.
- HTTP 402 `payment_required`: Missing or invalid PAYMENT-SIGNATURE; decode the PAYMENT-REQUIRED header
- HTTP 409 `payment_in_progress`: The same authorization nonce is already being settled; retry shortly
- HTTP 429 `rate_limited`: Too many requests from this client
- HTTP 503 `settlement_uncertain`: Settlement is unconfirmed; retry with the same PAYMENT-SIGNATURE
- HTTP 503 `settle_failed`: Settlement failed; retry with the same PAYMENT-SIGNATURE shortly
- HTTP 503 `facilitator_unavailable`: Payment facilitator unavailable
- HTTP 503 `facilitator_misconfigured`: Payment facilitator is not configured
- HTTP 503 `facilitator_unauthorized`: Payment facilitator rejected credentials
- HTTP 503 `ledger_unavailable`: Payment ledger unavailable
- HTTP 503 `payment_unavailable`: Payment processing unavailable

## Related tools

- [MELD-Na](https://magentlab.com/docs/meld-na) — Compute OPTN/UNOS 2016 MELD and MELD-Na from creatinine, bilirubin, INR, sodium, and dialysis.
- [Maddrey DF](https://magentlab.com/docs/maddrey) — Compute the 1978 Maddrey discriminant function from patient PT, control PT, and bilirubin.
- [FIB-4](https://magentlab.com/docs/fib4) — Compute the FIB-4 fibrosis index from age, AST, ALT, and platelets.

## Also searched as

- Child-Pugh score
- Child-Turcotte-Pugh
- CTP score
- cirrhosis class
- Pugh 1973
- Child Pugh

## Payment

Required query parameters must be present and valid. 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 EIP-3009 (scheme exact, assetTransferMethod eip3009) with validBefore = now + accepts[0].maxTimeoutSeconds (600 seconds). That window starts when you sign and must cover wallet confirmation plus CDP verify and settle. Magent retries transient facilitator 429/5xx before answering. Do not send upto or batch-settlement payloads; magent does not offer those schemes.
- Retry the same URL with PAYMENT-SIGNATURE (base64 JSON echoing accepted, payload, and extensions when present).
- Success is HTTP 200 JSON plus PAYMENT-RESPONSE. Settlement happens before the tool runs. HTTP 503 settlement_uncertain or settle_failed: retry the same PAYMENT-SIGNATURE. Mint a new 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.

- 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.
- not offered `batch-settlement`: Not offered. Payment-channel vouchers claimed later in batches. Not the same as POST {items} bulk (that is still exact).

Same-path POST {items} is still scheme exact: one EIP-3009 authorization for n times the GET unit. That is not x402 batch-settlement (payment channels / vouchers).

## Guarantees

- Invalid query parameters return HTTP 400 before settlement. You are not charged.
- Settlement finishes before the tool executes (paymentFlow upfront). 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.