# MELD 3.0 (Kim 2021)

MELD 3.0

Status: LIVE
Price: $0.005 USDC
`GET /api/calc/meld_3`
HTML: https://magentlab.com/docs/meld-3
Markdown: https://magentlab.com/docs/meld-3.md

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

## What it computes

Compute the Kim 2021 MELD 3.0 integer from sex, bilirubin, INR, creatinine, sodium, albumin, and dialysis.

## When to use

When an agent needs the published Kim 2021 MELD 3.0 integer and must not invent a listing order, substitute original MELD, or substitute MELD-Na.

## When not to use

- Not a medical device.
- Not a transplant listing or allocation order.
- Kim 2021 MELD 3.0 only. This is not original MELD (Kamath 2001) and not MELD-Na (OPTN 2016).
- Applies Kim 2021 lab bounds: creatinine 1.0–3.0 mg/dL (dialysis sets 3.0), bilirubin and INR floor 1.0, sodium 125–137 mmol/L, albumin 1.5–3.5 g/dL.
- Does not cap the integer at 40. Kim 2021 did not presume an allocation cap.
- Does not assign exception scores or listing priority.

## Formula

```
meld_3 = round(1.33*(female) + 4.56*ln(bilirubin) + 0.82*(137 - Na) - 0.24*(137 - Na)*ln(bilirubin) + 9.09*ln(INR) + 11.14*ln(creatinine) + 1.85*(3.5 - albumin) - 1.83*(3.5 - albumin)*ln(creatinine) + 6)
```

## Citation

[MELD 3.0: The Model for End-Stage Liver Disease Updated for the Modern Era](https://doi.org/10.1053/j.gastro.2021.08.050)
Kim WR, Mannalithara A, Heimbach JK, Kamath PS, Asrani SK, Biggins SW, et al.
Gastroenterology. 2021;161(6):1887-1895.e4
DOI: [10.1053/j.gastro.2021.08.050](https://doi.org/10.1053/j.gastro.2021.08.050)

## Worked example

### Male floors: bili 1, INR 1, Cr 1, Na 137, albumin 3.5

Given: `albumin_g_dl=3.5, bilirubin_mg_dl=1, creatinine_mg_dl=1, dialysis=false, inr=1, sex=male, sodium_mmol_l=137`

1. Kim 2021 bounds leave bilirubin, INR, and creatinine at 1.0; sodium at 137; albumin at 3.5. Male so female = 0. Not dialysis.
2. ln(1) = 0, so bilirubin, INR, creatinine, sodium, and albumin terms vanish.
3. meld_3 = round(6) → 6


## Also searched as

- MELD 3.0
- MELD 3
- Kim 2021 MELD
- model for end-stage liver disease 3.0
- MELD three point zero
- female sex MELD
- albumin MELD 3.0

## Parameters

- `sex` (string, required): Sex used in the Kim 2021 female term (female adds 1.33).
- `bilirubin_mg_dl` (number, optional): Total bilirubin in mg/dL (0.1-40). Provide this or bilirubin_umol_l. Kim 2021 floors at 1.0.
- `bilirubin_umol_l` (number, optional): Total bilirubin in µmol/L (2-684). Converted as mg/dL = µmol/L / 17.1.
- `inr` (number, required): INR (0.8-10). Kim 2021 floors at 1.0.
- `creatinine_mg_dl` (number, optional): Serum creatinine in mg/dL (0.1-20). Provide this or creatinine_umol_l. Kim 2021 floors at 1.0 and caps at 3.0.
- `creatinine_umol_l` (number, optional): Serum creatinine in µmol/L (9-1768). Converted as mg/dL = µmol/L / 88.42.
- `sodium_mmol_l` (number, required): Serum sodium in mmol/L (110-160). Kim 2021 clamps 125-137.
- `albumin_g_dl` (number, optional): Serum albumin in g/dL (1.0-6.0). Provide this or albumin_g_l. Kim 2021 clamps 1.5-3.5.
- `albumin_g_l` (number, optional): Serum albumin in g/L (10-60). Converted as g/dL = g/L / 10.
- `dialysis` (boolean, required): Dialysis twice in the prior week. true sets creatinine used to 3.0 (Kim 2021 ceiling).

## 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/meld_3`
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": [
    {
      "albumin_g_dl": "3.5",
      "bilirubin_mg_dl": "1",
      "creatinine_mg_dl": "1",
      "dialysis": "false",
      "inr": "1",
      "sex": "male",
      "sodium_mmol_l": "137"
    },
    {
      "albumin_g_dl": "3.5",
      "bilirubin_mg_dl": "1",
      "creatinine_mg_dl": "1",
      "dialysis": "false",
      "inr": "1",
      "sex": "male",
      "sodium_mmol_l": "137"
    }
  ]
}
```

Human paywall (two-item fixture): https://api.magentlab.com/paywall/bulk/meld-3

Example 200:

```json
{
  "count": 2,
  "path": "/api/calc/meld_3",
  "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": "Kim WR, Mannalithara A, Heimbach JK, Kamath PS, Asrani SK, Biggins SW, et al.",
        "doi": "10.1053/j.gastro.2021.08.050",
        "id": "kim-2021",
        "pmid": "34454066",
        "source": "Gastroenterology. 2021;161(6):1887-1895.e4",
        "title": "MELD 3.0: The Model for End-Stage Liver Disease Updated for the Modern Era"
      },
      "formula": "kim_meld_3_2021",
      "formula_expression": "meld_3 = round(1.33*(female) + 4.56*ln(bilirubin) + 0.82*(137 - Na) - 0.24*(137 - Na)*ln(bilirubin) + 9.09*ln(INR) + 11.14*ln(creatinine) + 1.85*(3.5 - albumin) - 1.83*(3.5 - albumin)*ln(creatinine) + 6)",
      "albumin_g_dl": 3.5,
      "inr": 1.0,
      "bilirubin_mg_dl": 1.0,
      "creatinine_mg_dl": 1.0,
      "sex": "male",
      "sodium_mmol_l": 137.0,
      "female": false,
      "bilirubin_used_mg_dl": 1.0,
      "creatinine_used_mg_dl": 1.0,
      "dialysis": false,
      "inr_used": 1.0,
      "sodium_used_mmol_l": 137.0,
      "albumin_used_g_dl": 3.5,
      "meld_3": 6
    },
    {
      "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": "Kim WR, Mannalithara A, Heimbach JK, Kamath PS, Asrani SK, Biggins SW, et al.",
        "doi": "10.1053/j.gastro.2021.08.050",
        "id": "kim-2021",
        "pmid": "34454066",
        "source": "Gastroenterology. 2021;161(6):1887-1895.e4",
        "title": "MELD 3.0: The Model for End-Stage Liver Disease Updated for the Modern Era"
      },
      "formula": "kim_meld_3_2021",
      "formula_expression": "meld_3 = round(1.33*(female) + 4.56*ln(bilirubin) + 0.82*(137 - Na) - 0.24*(137 - Na)*ln(bilirubin) + 9.09*ln(INR) + 11.14*ln(creatinine) + 1.85*(3.5 - albumin) - 1.83*(3.5 - albumin)*ln(creatinine) + 6)",
      "albumin_g_dl": 3.5,
      "inr": 1.0,
      "bilirubin_mg_dl": 1.0,
      "creatinine_mg_dl": 1.0,
      "sex": "male",
      "sodium_mmol_l": 137.0,
      "female": false,
      "bilirubin_used_mg_dl": 1.0,
      "creatinine_used_mg_dl": 1.0,
      "dialysis": false,
      "inr_used": 1.0,
      "sodium_used_mmol_l": 137.0,
      "albumin_used_g_dl": 3.5,
      "meld_3": 6
    }
  ]
}
```

## Response fields

- `formula` (string): kim_meld_3_2021
- `formula_expression` (string): Exact expression used
- `sex` (string): female or male
- `female` (boolean): true when the Kim 2021 female term applies
- `bilirubin_mg_dl` (number): Input bilirubin in mg/dL
- `inr` (number): Input INR
- `creatinine_mg_dl` (number): Input creatinine in mg/dL
- `sodium_mmol_l` (number): Input sodium
- `albumin_g_dl` (number): Input albumin in g/dL
- `dialysis` (boolean): Dialysis flag
- `bilirubin_used_mg_dl` (number): Bilirubin after Kim 2021 floor of 1.0
- `inr_used` (number): INR after Kim 2021 floor of 1.0
- `creatinine_used_mg_dl` (number): Creatinine after Kim 2021 1.0-3.0 bounds; dialysis forces 3.0
- `sodium_used_mmol_l` (number): Sodium after Kim 2021 125-137 clamp
- `albumin_used_g_dl` (number): Albumin after Kim 2021 1.5-3.5 clamp
- `meld_3` (integer): Kim 2021 MELD 3.0, nearest integer
- `citation` (object): Kim 2021 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": "Kim WR, Mannalithara A, Heimbach JK, Kamath PS, Asrani SK, Biggins SW, et al.",
    "doi": "10.1053/j.gastro.2021.08.050",
    "id": "kim-2021",
    "pmid": "34454066",
    "source": "Gastroenterology. 2021;161(6):1887-1895.e4",
    "title": "MELD 3.0: The Model for End-Stage Liver Disease Updated for the Modern Era"
  },
  "formula": "kim_meld_3_2021",
  "formula_expression": "meld_3 = round(1.33*(female) + 4.56*ln(bilirubin) + 0.82*(137 - Na) - 0.24*(137 - Na)*ln(bilirubin) + 9.09*ln(INR) + 11.14*ln(creatinine) + 1.85*(3.5 - albumin) - 1.83*(3.5 - albumin)*ln(creatinine) + 6)",
  "albumin_g_dl": 3.5,
  "inr": 1.0,
  "bilirubin_mg_dl": 1.0,
  "creatinine_mg_dl": 1.0,
  "sex": "male",
  "sodium_mmol_l": 137.0,
  "female": false,
  "bilirubin_used_mg_dl": 1.0,
  "creatinine_used_mg_dl": 1.0,
  "dialysis": false,
  "inr_used": 1.0,
  "sodium_used_mmol_l": 137.0,
  "albumin_used_g_dl": 3.5,
  "meld_3": 6
}
```

## Errors

- HTTP 400 `invalid_sex`: sex must be female or male Returned before settlement; you are not charged.
- 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_inr`: inr must be a number from 0.8 to 10 Returned before settlement; you are not charged.
- HTTP 400 `invalid_creatinine`: creatinine_mg_dl (0.1-20) or creatinine_umol_l (9-1768) is required Returned before settlement; you are not charged.
- HTTP 400 `invalid_sodium`: sodium_mmol_l must be a number from 110 to 160 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_flag`: boolean clinical flags must be true or false 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

- [MELD](https://magentlab.com/docs/meld) — Compute the Kamath 2001 model for end-stage liver disease (MELD) integer from creatinine, bilirubin, INR, and cholestatic or alcoholic etiology.
- [MELD-Na](https://magentlab.com/docs/meld-na) — Compute OPTN/UNOS 2016 MELD and MELD-Na from creatinine, bilirubin, INR, sodium, and dialysis.
- [Child–Pugh](https://magentlab.com/docs/child-pugh) — Compute the Child–Turcotte–Pugh cirrhosis severity score from bilirubin, albumin, INR, encephalopathy, and ascites.

## 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 of accepted and payload). Magent attaches canonical extensions.bazaar on CDP verify/settle; echoing 402 bazaar is optional.
- 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. 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.
