# Classic Kawasaki disease criteria

Kawasaki

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

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

## What it computes

Apply McCrindle 2017 classic/complete Kawasaki disease criteria and return complete or not_complete from fever_days and five caller-assigned principal features.

## When to use

When an agent already has fever duration in days and the five principal clinical features as assigned by the caller and needs the published classic/complete Kawasaki classification. magent does not examine the patient or read an echocardiogram.

## When not to use

- Not a medical device and not a diagnosis of Kawasaki disease.
- This tool is classic/complete Kawasaki disease criteria from McCrindle 2017 only. It is not the incomplete-KD laboratory or echocardiogram workup.
- magent does not examine the patient or read an echocardiogram. The caller assigns fever_days and the five principal features as already determined.
- The rare 3-day fever clinician exception in the statement is not implemented. Fever of 3 days is not_complete even with all 5 principal features.

## Formula

```
complete iff principal_feature_count >= 4 and fever_days >= 4 (McCrindle 2017; classic KD with fever_days >= 5 and >=4 features, or 4 days of fever when >=4 principal features). principal_feature_count is the number of true flags among oral_mucosal_changes, bilateral_conjunctival_injection, rash, extremity_changes, cervical_lymphadenopathy. Not incomplete-KD labs/echo. Not the 3-day clinician exception
```

## Citation

[Diagnosis, Treatment, and Long-Term Management of Kawasaki Disease: A Scientific Statement for Health Professionals From the American Heart Association](https://doi.org/10.1161/CIR.0000000000000484)
McCrindle BW, Rowley AH, Newburger JW, Burns JC, Bolger AF, Gewitz M, Baker AL, Jackson MA, Takahashi M, Shah PB, Kobayashi T, Wu MH, Saji TT, Pahl E
Circulation. 2017;135(17):e927-e999
DOI: [10.1161/CIR.0000000000000484](https://doi.org/10.1161/CIR.0000000000000484)

## Worked example

### Five days of fever and all five principal features

Given: `bilateral_conjunctival_injection=true, cervical_lymphadenopathy=true, extremity_changes=true, fever_days=5, oral_mucosal_changes=true, rash=true`

1. fever_days 5 >= 4
2. All five principal features true → principal_feature_count 5 >= 4
3. classification complete


## Also searched as

- Kawasaki disease
- classic Kawasaki
- complete Kawasaki disease
- KD diagnostic criteria
- AHA Kawasaki 2017
- mucocutaneous lymph node syndrome
- Kawasaki fever criteria
- principal features Kawasaki
- McCrindle Kawasaki

## Parameters

- `fever_days` (integer, required): Duration of fever in days (integer 1-30). Classic complete KD requires fever_days >= 5 with >=4 principal features; with >=4 principal features the diagnosis may be made with 4 days of fever (McCrindle 2017). The 3-day clinician exception is not this tool.
- `oral_mucosal_changes` (boolean, required): Principal feature: erythema and cracking of lips, strawberry tongue, and/or erythema of oral and pharyngeal mucosa (McCrindle 2017). true or false as assigned by the caller. magent does not examine the patient.
- `bilateral_conjunctival_injection` (boolean, required): Principal feature: bilateral bulbar conjunctival injection without exudate (McCrindle 2017). true or false as assigned by the caller. magent does not examine the patient.
- `rash` (boolean, required): Principal feature: rash — maculopapular, diffuse erythroderma, or erythema multiforme-like (McCrindle 2017). true or false as assigned by the caller. magent does not examine the patient.
- `extremity_changes` (boolean, required): Principal feature: erythema and edema of the hands and feet in the acute phase and/or periungual desquamation in the subacute phase (McCrindle 2017). true or false as assigned by the caller. magent does not examine the patient.
- `cervical_lymphadenopathy` (boolean, required): Principal feature: cervical lymphadenopathy (>=1.5 cm diameter), usually unilateral (McCrindle 2017). true or false as assigned by the caller. magent does not examine the patient.

## 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/kawasaki`
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": [
    {
      "bilateral_conjunctival_injection": "true",
      "cervical_lymphadenopathy": "true",
      "extremity_changes": "true",
      "fever_days": "5",
      "oral_mucosal_changes": "true",
      "rash": "true"
    },
    {
      "bilateral_conjunctival_injection": "true",
      "cervical_lymphadenopathy": "true",
      "extremity_changes": "true",
      "fever_days": "5",
      "oral_mucosal_changes": "true",
      "rash": "true"
    }
  ]
}
```

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

Example 200:

```json
{
  "count": 2,
  "path": "/api/calc/kawasaki",
  "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": "McCrindle BW, Rowley AH, Newburger JW, Burns JC, Bolger AF, Gewitz M, Baker AL, Jackson MA, Takahashi M, Shah PB, Kobayashi T, Wu MH, Saji TT, Pahl E",
        "doi": "10.1161/CIR.0000000000000484",
        "id": "mccrindle-2017",
        "pmid": "28356445",
        "source": "Circulation. 2017;135(17):e927-e999",
        "title": "Diagnosis, Treatment, and Long-Term Management of Kawasaki Disease: A Scientific Statement for Health Professionals From the American Heart Association"
      },
      "formula": "kawasaki",
      "formula_expression": "complete iff principal_feature_count >= 4 and fever_days >= 4 (McCrindle 2017; classic KD with fever_days >= 5 and >=4 features, or 4 days of fever when >=4 principal features). principal_feature_count is the number of true flags among oral_mucosal_changes, bilateral_conjunctival_injection, rash, extremity_changes, cervical_lymphadenopathy. Not incomplete-KD labs/echo. Not the 3-day clinician exception",
      "criteria": [
        {
          "value": 5,
          "factor": "fever_days_ge_4",
          "met": true
        },
        {
          "factor": "oral_mucosal_changes",
          "met": true
        },
        {
          "factor": "bilateral_conjunctival_injection",
          "met": true
        },
        {
          "factor": "rash",
          "met": true
        },
        {
          "factor": "extremity_changes",
          "met": true
        },
        {
          "factor": "cervical_lymphadenopathy",
          "met": true
        },
        {
          "value": 5,
          "factor": "principal_feature_count_ge_4",
          "met": true
        }
      ],
      "classification": "complete",
      "bilateral_conjunctival_injection": true,
      "cervical_lymphadenopathy": true,
      "extremity_changes": true,
      "fever_days": 5,
      "oral_mucosal_changes": true,
      "principal_feature_count": 5,
      "rash": true
    },
    {
      "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": "McCrindle BW, Rowley AH, Newburger JW, Burns JC, Bolger AF, Gewitz M, Baker AL, Jackson MA, Takahashi M, Shah PB, Kobayashi T, Wu MH, Saji TT, Pahl E",
        "doi": "10.1161/CIR.0000000000000484",
        "id": "mccrindle-2017",
        "pmid": "28356445",
        "source": "Circulation. 2017;135(17):e927-e999",
        "title": "Diagnosis, Treatment, and Long-Term Management of Kawasaki Disease: A Scientific Statement for Health Professionals From the American Heart Association"
      },
      "formula": "kawasaki",
      "formula_expression": "complete iff principal_feature_count >= 4 and fever_days >= 4 (McCrindle 2017; classic KD with fever_days >= 5 and >=4 features, or 4 days of fever when >=4 principal features). principal_feature_count is the number of true flags among oral_mucosal_changes, bilateral_conjunctival_injection, rash, extremity_changes, cervical_lymphadenopathy. Not incomplete-KD labs/echo. Not the 3-day clinician exception",
      "criteria": [
        {
          "value": 5,
          "factor": "fever_days_ge_4",
          "met": true
        },
        {
          "factor": "oral_mucosal_changes",
          "met": true
        },
        {
          "factor": "bilateral_conjunctival_injection",
          "met": true
        },
        {
          "factor": "rash",
          "met": true
        },
        {
          "factor": "extremity_changes",
          "met": true
        },
        {
          "factor": "cervical_lymphadenopathy",
          "met": true
        },
        {
          "value": 5,
          "factor": "principal_feature_count_ge_4",
          "met": true
        }
      ],
      "classification": "complete",
      "bilateral_conjunctival_injection": true,
      "cervical_lymphadenopathy": true,
      "extremity_changes": true,
      "fever_days": 5,
      "oral_mucosal_changes": true,
      "principal_feature_count": 5,
      "rash": true
    }
  ]
}
```

## Response fields

- `formula` (string): kawasaki
- `formula_expression` (string): McCrindle 2017 classic/complete Kawasaki disease rule
- `fever_days` (integer): Echo of fever duration in days
- `oral_mucosal_changes` (boolean): Echo of the caller-assigned oral mucosal principal feature
- `bilateral_conjunctival_injection` (boolean): Echo of the caller-assigned conjunctival principal feature
- `rash` (boolean): Echo of the caller-assigned rash principal feature
- `extremity_changes` (boolean): Echo of the caller-assigned extremity principal feature
- `cervical_lymphadenopathy` (boolean): Echo of the caller-assigned cervical lymphadenopathy principal feature
- `principal_feature_count` (integer): Number of true principal features (0-5)
- `classification` (string): complete when principal_feature_count >= 4 and fever_days >= 4; otherwise not_complete. Not incomplete KD. Not a diagnosis.
- `criteria` (array): Rows for fever_days_ge_4, each principal feature, and principal_feature_count_ge_4 with factor, met, and value when numeric
- `citation` (object): McCrindle 2017 Circulation 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": "McCrindle BW, Rowley AH, Newburger JW, Burns JC, Bolger AF, Gewitz M, Baker AL, Jackson MA, Takahashi M, Shah PB, Kobayashi T, Wu MH, Saji TT, Pahl E",
    "doi": "10.1161/CIR.0000000000000484",
    "id": "mccrindle-2017",
    "pmid": "28356445",
    "source": "Circulation. 2017;135(17):e927-e999",
    "title": "Diagnosis, Treatment, and Long-Term Management of Kawasaki Disease: A Scientific Statement for Health Professionals From the American Heart Association"
  },
  "formula": "kawasaki",
  "formula_expression": "complete iff principal_feature_count >= 4 and fever_days >= 4 (McCrindle 2017; classic KD with fever_days >= 5 and >=4 features, or 4 days of fever when >=4 principal features). principal_feature_count is the number of true flags among oral_mucosal_changes, bilateral_conjunctival_injection, rash, extremity_changes, cervical_lymphadenopathy. Not incomplete-KD labs/echo. Not the 3-day clinician exception",
  "criteria": [
    {
      "value": 5,
      "factor": "fever_days_ge_4",
      "met": true
    },
    {
      "factor": "oral_mucosal_changes",
      "met": true
    },
    {
      "factor": "bilateral_conjunctival_injection",
      "met": true
    },
    {
      "factor": "rash",
      "met": true
    },
    {
      "factor": "extremity_changes",
      "met": true
    },
    {
      "factor": "cervical_lymphadenopathy",
      "met": true
    },
    {
      "value": 5,
      "factor": "principal_feature_count_ge_4",
      "met": true
    }
  ],
  "classification": "complete",
  "bilateral_conjunctival_injection": true,
  "cervical_lymphadenopathy": true,
  "extremity_changes": true,
  "fever_days": 5,
  "oral_mucosal_changes": true,
  "principal_feature_count": 5,
  "rash": true
}
```

## Errors

- HTTP 400 `invalid_fever_days`: fever_days must be an integer from 1 to 30. 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

- [Westley croup](https://magentlab.com/docs/westley-croup) — Sum the Westley 1978 croup clinical score from caller-assigned consciousness, cyanosis, stridor, air entry, and retractions (maximum 17).
- [Bacterial Meningitis Score](https://magentlab.com/docs/bacterial-meningitis) — Sum the Nigrovic 2002 Bacterial Meningitis Score weights for children with CSF pleocytosis and return very_low_risk (0) or not_low_risk (≥1).

## 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.