# HFA-ICOS RAF-MEK inhibitor baseline CV risk

HFA-ICOS RAF-MEK inhibitor baseline CV risk

Status: LIVE
Price: $0.005 USDC
`GET /api/calc/hfa_icos_raf_mek`
HTML: https://magentlab.com/docs/hfa-icos-raf-mek
Markdown: https://magentlab.com/docs/hfa-icos-raf-mek.md

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

## What it computes

Classify Lyon 2020 HFA-ICOS baseline cardiovascular risk before combination RAF and MEK inhibitors as very_high, high, medium, or low from that table's printed factors and the shared medium-point rule.

## When to use

When an agent already has age, LVEF, and the yes/no Lyon 2020 RAF-MEK table factors and needs the published HFA-ICOS class plus the expert-opinion cardiotoxicity guide. magent does not examine the patient, read an echocardiogram, or assay biomarkers. Not a treatment order.

## When not to use

- Not a medical device. Not a treatment order, monitoring schedule, or cardiotoxicity diagnosis.
- This RAF-MEK table has no printed LVEF <50 High row and no High age band. Age ≥65 is Medium 1 only. LVEF <50 does not invent a High factor.
- Cardiotoxicity percents are the paper's expert-opinion guide (<2% / 2-9% / 10-19% / ≥20%), not a patient-specific probability.
- Flags are caller-assigned. magent does not diagnose heart failure, compute BMI or eGFR, or assay troponin or natriuretic peptides.

## Formula

```
HFA-ICOS RAF-MEK (Lyon 2020): very_high if heart_failure_or_cardiomyopathy; high if mi_or_cabg or stable_angina or severe_valvular_heart_disease or prior_anthracycline or medium_points>=5; medium if medium_points 2-4; low if medium_points 0-1; medium_points = M2 (lvef 50-54, elevated_troponin, elevated_bnp, hypertension, prior_left_chest_or_mediastinal_rt) + M1 (arrhythmia, age>=65, diabetes, ckd, current_or_significant_smoker, obesity); LVEF <50 is not a printed High row on this table; age>=65 Medium 1 only (no High age band); cardiotoxicity_guide low <2%, medium 2-9%, high 10-19%, very_high >=20%
```

## Citation

[Baseline cardiovascular risk assessment in cancer patients scheduled to receive cardiotoxic cancer therapies: a position statement and new risk assessment tools from the Cardio-Oncology Study Group of the Heart Failure Association of the European Society of Cardiology in collaboration with the International Cardio-Oncology Society](https://doi.org/10.1002/ejhf.1920)
Lyon AR, Dent S, Stanway S, et al.
Eur J Heart Fail. 2020;22(11):1945-1960
DOI: [10.1002/ejhf.1920](https://doi.org/10.1002/ejhf.1920)

## Worked example

### No printed factors

Given: `age_years=50, arrhythmia=false, ckd=false, current_or_significant_smoker=false, diabetes=false, elevated_bnp=false, elevated_troponin=false, heart_failure_or_cardiomyopathy=false, hypertension=false, lvef_percent=60, mi_or_cabg=false, obesity=false, prior_anthracycline=false, prior_left_chest_or_mediastinal_rt=false, severe_valvular_heart_disease=false, stable_angina=false`

1. age 50 < 65 → no Medium 1; LVEF 60 ≥ 55 → no Medium 2
2. medium_points = 0; risk_level = low; cardiotoxicity_guide <2%


### Heart failure or cardiomyopathy

Given: `age_years=50, arrhythmia=false, ckd=false, current_or_significant_smoker=false, diabetes=false, elevated_bnp=false, elevated_troponin=false, heart_failure_or_cardiomyopathy=true, hypertension=false, lvef_percent=60, mi_or_cabg=false, obesity=false, prior_anthracycline=false, prior_left_chest_or_mediastinal_rt=false, severe_valvular_heart_disease=false, stable_angina=false`

1. heart_failure_or_cardiomyopathy is Very high
2. risk_level = very_high; cardiotoxicity_guide >=20%


### Prior anthracycline

Given: `age_years=50, arrhythmia=false, ckd=false, current_or_significant_smoker=false, diabetes=false, elevated_bnp=false, elevated_troponin=false, heart_failure_or_cardiomyopathy=false, hypertension=false, lvef_percent=60, mi_or_cabg=false, obesity=false, prior_anthracycline=true, prior_left_chest_or_mediastinal_rt=false, severe_valvular_heart_disease=false, stable_angina=false`

1. prior_anthracycline is High
2. risk_level = high; cardiotoxicity_guide 10-19%


### Hypertension only

Given: `age_years=50, arrhythmia=false, ckd=false, current_or_significant_smoker=false, diabetes=false, elevated_bnp=false, elevated_troponin=false, heart_failure_or_cardiomyopathy=false, hypertension=true, lvef_percent=60, mi_or_cabg=false, obesity=false, prior_anthracycline=false, prior_left_chest_or_mediastinal_rt=false, severe_valvular_heart_disease=false, stable_angina=false`

1. hypertension is Medium 2
2. medium_points = 2; risk_level = medium; cardiotoxicity_guide 2-9%


### Age 70 only

Given: `age_years=70, arrhythmia=false, ckd=false, current_or_significant_smoker=false, diabetes=false, elevated_bnp=false, elevated_troponin=false, heart_failure_or_cardiomyopathy=false, hypertension=false, lvef_percent=60, mi_or_cabg=false, obesity=false, prior_anthracycline=false, prior_left_chest_or_mediastinal_rt=false, severe_valvular_heart_disease=false, stable_angina=false`

1. age ≥65 is Medium 1; no High age band on this table
2. medium_points = 1; risk_level = low (one Medium 1)


## Also searched as

- HFA-ICOS RAF-MEK
- RAF MEK inhibitor cardiotoxicity
- Lyon 2020 RAF-MEK
- combination RAF MEK baseline risk
- cardio-oncology RAF MEK

## Parameters

- `age_years` (integer, required): Age in whole years (18-100). Lyon 2020 RAF-MEK table: age ≥65 is Medium 1. There is no High age band on this table. magent does not read an identity document.
- `lvef_percent` (integer, required): Baseline LVEF in whole percent (10-80) as assigned by the caller. 50-54 is Medium 2. ≥55 adds no points. This table has no printed LVEF <50 High row; LVEF <50 does not raise risk_level by itself. magent does not read an echocardiogram.
- `heart_failure_or_cardiomyopathy` (boolean, required): Heart failure or cardiomyopathy as assigned by the caller (Lyon 2020 RAF-MEK table). true is Very high. magent does not diagnose heart failure.
- `mi_or_cabg` (boolean, required): Myocardial infarction or CABG as assigned by the caller (Lyon 2020 RAF-MEK table). true is High.
- `stable_angina` (boolean, required): Stable angina as assigned by the caller (Lyon 2020 RAF-MEK table). true is High. magent does not diagnose angina.
- `severe_valvular_heart_disease` (boolean, required): Severe valvular heart disease as assigned by the caller (Lyon 2020 RAF-MEK table). true is High.
- `prior_anthracycline` (boolean, required): Prior anthracycline exposure as assigned by the caller (Lyon 2020 RAF-MEK table). true is High. magent does not read a chemotherapy record.
- `elevated_troponin` (boolean, required): Elevated baseline troponin above the local laboratory upper limit of normal as assigned by the caller (Lyon 2020 RAF-MEK table). true is Medium 2. magent does not assay troponin.
- `elevated_bnp` (boolean, required): Elevated baseline BNP or NT-proBNP above the local laboratory upper limit of normal as assigned by the caller (Lyon 2020 RAF-MEK table). true is Medium 2. magent does not assay natriuretic peptides.
- `hypertension` (boolean, required): Hypertension (systolic >140 mm Hg or diastolic >90 mm Hg, or on treatment) as assigned by the caller (Lyon 2020 RAF-MEK table). true is Medium 2. magent does not measure blood pressure.
- `prior_left_chest_or_mediastinal_rt` (boolean, required): Prior radiotherapy to the left chest or mediastinum as assigned by the caller (Lyon 2020 RAF-MEK table). true is Medium 2.
- `arrhythmia` (boolean, required): Atrial fibrillation, atrial flutter, ventricular tachycardia, or ventricular fibrillation as assigned by the caller (Lyon 2020 RAF-MEK table footnote). true is Medium 1. magent does not read an ECG.
- `diabetes` (boolean, required): Diabetes mellitus (glycated haemoglobin >7.0% or >53 mmol/mol, or on treatment) as assigned by the caller (Lyon 2020 RAF-MEK table). true is Medium 1. magent does not assay haemoglobin A1c.
- `ckd` (boolean, required): Chronic kidney disease (estimated glomerular filtration rate <60 mL/min/1.73 m2) as assigned by the caller (Lyon 2020 RAF-MEK table). true is Medium 1. magent does not compute eGFR.
- `current_or_significant_smoker` (boolean, required): Current smoker or significant smoking history as assigned by the caller (Lyon 2020 RAF-MEK table). true is Medium 1.
- `obesity` (boolean, required): Obesity (BMI >30 kg/m2) as assigned by the caller (Lyon 2020 RAF-MEK table). true is Medium 1. magent does not compute BMI.

## 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/hfa_icos_raf_mek`
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_years": "50",
      "arrhythmia": "false",
      "ckd": "false",
      "current_or_significant_smoker": "false",
      "diabetes": "false",
      "elevated_bnp": "false",
      "elevated_troponin": "false",
      "heart_failure_or_cardiomyopathy": "false",
      "hypertension": "false",
      "lvef_percent": "60",
      "mi_or_cabg": "false",
      "obesity": "false",
      "prior_anthracycline": "false",
      "prior_left_chest_or_mediastinal_rt": "false",
      "severe_valvular_heart_disease": "false",
      "stable_angina": "false"
    },
    {
      "age_years": "50",
      "arrhythmia": "false",
      "ckd": "false",
      "current_or_significant_smoker": "false",
      "diabetes": "false",
      "elevated_bnp": "false",
      "elevated_troponin": "false",
      "heart_failure_or_cardiomyopathy": "false",
      "hypertension": "false",
      "lvef_percent": "60",
      "mi_or_cabg": "false",
      "obesity": "false",
      "prior_anthracycline": "false",
      "prior_left_chest_or_mediastinal_rt": "false",
      "severe_valvular_heart_disease": "false",
      "stable_angina": "false"
    }
  ]
}
```

Human paywall (two-item fixture): https://api.magentlab.com/paywall/bulk/hfa-icos-raf-mek

Example 200:

```json
{
  "count": 2,
  "path": "/api/calc/hfa_icos_raf_mek",
  "items": [
    {
      "components": [
        {
          "factor": "heart_failure_or_cardiomyopathy",
          "points": 0,
          "present": false,
          "tier": "very_high"
        },
        {
          "factor": "mi_or_cabg",
          "points": 0,
          "present": false,
          "tier": "high"
        },
        {
          "factor": "stable_angina",
          "points": 0,
          "present": false,
          "tier": "high"
        },
        {
          "factor": "severe_valvular_heart_disease",
          "points": 0,
          "present": false,
          "tier": "high"
        },
        {
          "value": 60,
          "factor": "lvef_50_54",
          "points": 0,
          "present": false,
          "tier": "medium"
        },
        {
          "factor": "arrhythmia",
          "points": 0,
          "present": false,
          "tier": "medium"
        },
        {
          "factor": "elevated_troponin",
          "points": 0,
          "present": false,
          "tier": "medium"
        },
        {
          "factor": "elevated_bnp",
          "points": 0,
          "present": false,
          "tier": "medium"
        },
        {
          "value": 50,
          "factor": "age_ge_65",
          "points": 0,
          "present": false,
          "tier": "medium"
        },
        {
          "factor": "hypertension",
          "points": 0,
          "present": false,
          "tier": "medium"
        },
        {
          "factor": "diabetes",
          "points": 0,
          "present": false,
          "tier": "medium"
        },
        {
          "factor": "ckd",
          "points": 0,
          "present": false,
          "tier": "medium"
        },
        {
          "factor": "prior_anthracycline",
          "points": 0,
          "present": false,
          "tier": "high"
        },
        {
          "factor": "prior_left_chest_or_mediastinal_rt",
          "points": 0,
          "present": false,
          "tier": "medium"
        },
        {
          "factor": "current_or_significant_smoker",
          "points": 0,
          "present": false,
          "tier": "medium"
        },
        {
          "factor": "obesity",
          "points": 0,
          "present": false,
          "tier": "medium"
        }
      ],
      "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": "Lyon AR, Dent S, Stanway S, et al.",
        "doi": "10.1002/ejhf.1920",
        "id": "lyon-2020",
        "pmid": "32458582",
        "source": "Eur J Heart Fail. 2020;22(11):1945-1960",
        "title": "Baseline cardiovascular risk assessment in cancer patients scheduled to receive cardiotoxic cancer therapies: a position statement and new risk assessment tools from the Cardio-Oncology Study Group of the Heart Failure Association of the European Society of Cardiology in collaboration with the International Cardio-Oncology Society"
      },
      "formula": "hfa_icos_raf_mek",
      "formula_expression": "HFA-ICOS RAF-MEK (Lyon 2020): very_high if heart_failure_or_cardiomyopathy; high if mi_or_cabg or stable_angina or severe_valvular_heart_disease or prior_anthracycline or medium_points>=5; medium if medium_points 2-4; low if medium_points 0-1; medium_points = M2 (lvef 50-54, elevated_troponin, elevated_bnp, hypertension, prior_left_chest_or_mediastinal_rt) + M1 (arrhythmia, age>=65, diabetes, ckd, current_or_significant_smoker, obesity); LVEF <50 is not a printed High row on this table; age>=65 Medium 1 only (no High age band); cardiotoxicity_guide low <2%, medium 2-9%, high 10-19%, very_high >=20%",
      "age_years": 50,
      "cardiotoxicity_guide": "<2%",
      "lvef_percent": 60,
      "medium_points": 0,
      "risk_level": "low"
    },
    {
      "components": [
        {
          "factor": "heart_failure_or_cardiomyopathy",
          "points": 0,
          "present": false,
          "tier": "very_high"
        },
        {
          "factor": "mi_or_cabg",
          "points": 0,
          "present": false,
          "tier": "high"
        },
        {
          "factor": "stable_angina",
          "points": 0,
          "present": false,
          "tier": "high"
        },
        {
          "factor": "severe_valvular_heart_disease",
          "points": 0,
          "present": false,
          "tier": "high"
        },
        {
          "value": 60,
          "factor": "lvef_50_54",
          "points": 0,
          "present": false,
          "tier": "medium"
        },
        {
          "factor": "arrhythmia",
          "points": 0,
          "present": false,
          "tier": "medium"
        },
        {
          "factor": "elevated_troponin",
          "points": 0,
          "present": false,
          "tier": "medium"
        },
        {
          "factor": "elevated_bnp",
          "points": 0,
          "present": false,
          "tier": "medium"
        },
        {
          "value": 50,
          "factor": "age_ge_65",
          "points": 0,
          "present": false,
          "tier": "medium"
        },
        {
          "factor": "hypertension",
          "points": 0,
          "present": false,
          "tier": "medium"
        },
        {
          "factor": "diabetes",
          "points": 0,
          "present": false,
          "tier": "medium"
        },
        {
          "factor": "ckd",
          "points": 0,
          "present": false,
          "tier": "medium"
        },
        {
          "factor": "prior_anthracycline",
          "points": 0,
          "present": false,
          "tier": "high"
        },
        {
          "factor": "prior_left_chest_or_mediastinal_rt",
          "points": 0,
          "present": false,
          "tier": "medium"
        },
        {
          "factor": "current_or_significant_smoker",
          "points": 0,
          "present": false,
          "tier": "medium"
        },
        {
          "factor": "obesity",
          "points": 0,
          "present": false,
          "tier": "medium"
        }
      ],
      "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": "Lyon AR, Dent S, Stanway S, et al.",
        "doi": "10.1002/ejhf.1920",
        "id": "lyon-2020",
        "pmid": "32458582",
        "source": "Eur J Heart Fail. 2020;22(11):1945-1960",
        "title": "Baseline cardiovascular risk assessment in cancer patients scheduled to receive cardiotoxic cancer therapies: a position statement and new risk assessment tools from the Cardio-Oncology Study Group of the Heart Failure Association of the European Society of Cardiology in collaboration with the International Cardio-Oncology Society"
      },
      "formula": "hfa_icos_raf_mek",
      "formula_expression": "HFA-ICOS RAF-MEK (Lyon 2020): very_high if heart_failure_or_cardiomyopathy; high if mi_or_cabg or stable_angina or severe_valvular_heart_disease or prior_anthracycline or medium_points>=5; medium if medium_points 2-4; low if medium_points 0-1; medium_points = M2 (lvef 50-54, elevated_troponin, elevated_bnp, hypertension, prior_left_chest_or_mediastinal_rt) + M1 (arrhythmia, age>=65, diabetes, ckd, current_or_significant_smoker, obesity); LVEF <50 is not a printed High row on this table; age>=65 Medium 1 only (no High age band); cardiotoxicity_guide low <2%, medium 2-9%, high 10-19%, very_high >=20%",
      "age_years": 50,
      "cardiotoxicity_guide": "<2%",
      "lvef_percent": 60,
      "medium_points": 0,
      "risk_level": "low"
    }
  ]
}
```

## Response fields

- `formula` (string): hfa_icos_raf_mek
- `formula_expression` (string): Exact expression used
- `age_years` (integer): Age in years used for the ≥65 Medium 1 band
- `lvef_percent` (integer): LVEF percent used for the 50-54 Medium 2 band
- `risk_level` (string): very_high, high, medium, or low from the Lyon 2020 RAF-MEK table and the shared HFA-ICOS medium-point rule (0-1 low, 2-4 medium, ≥5 high). A class, not a treatment order. LVEF <50 is not a printed High factor on this table.
- `medium_points` (integer): Sum of Medium 1 and Medium 2 points only (High and Very high are not added)
- `cardiotoxicity_guide` (string): Lyon 2020 expert-opinion cardiotoxicity guide: <2% (low), 2-9% (medium), 10-19% (high), >=20% (very_high). A guide, not a patient-specific probability.
- `components` (array): Per-factor present, points, and tier
- `citation` (object): Lyon et al. Eur J Heart Fail 2020 citation
- `disclaimer` (string): Not-a-device notice

## Example JSON

Frozen fixture. Not a live lookup.

```json
{
  "components": [
    {
      "factor": "heart_failure_or_cardiomyopathy",
      "points": 0,
      "present": false,
      "tier": "very_high"
    },
    {
      "factor": "mi_or_cabg",
      "points": 0,
      "present": false,
      "tier": "high"
    },
    {
      "factor": "stable_angina",
      "points": 0,
      "present": false,
      "tier": "high"
    },
    {
      "factor": "severe_valvular_heart_disease",
      "points": 0,
      "present": false,
      "tier": "high"
    },
    {
      "value": 60,
      "factor": "lvef_50_54",
      "points": 0,
      "present": false,
      "tier": "medium"
    },
    {
      "factor": "arrhythmia",
      "points": 0,
      "present": false,
      "tier": "medium"
    },
    {
      "factor": "elevated_troponin",
      "points": 0,
      "present": false,
      "tier": "medium"
    },
    {
      "factor": "elevated_bnp",
      "points": 0,
      "present": false,
      "tier": "medium"
    },
    {
      "value": 50,
      "factor": "age_ge_65",
      "points": 0,
      "present": false,
      "tier": "medium"
    },
    {
      "factor": "hypertension",
      "points": 0,
      "present": false,
      "tier": "medium"
    },
    {
      "factor": "diabetes",
      "points": 0,
      "present": false,
      "tier": "medium"
    },
    {
      "factor": "ckd",
      "points": 0,
      "present": false,
      "tier": "medium"
    },
    {
      "factor": "prior_anthracycline",
      "points": 0,
      "present": false,
      "tier": "high"
    },
    {
      "factor": "prior_left_chest_or_mediastinal_rt",
      "points": 0,
      "present": false,
      "tier": "medium"
    },
    {
      "factor": "current_or_significant_smoker",
      "points": 0,
      "present": false,
      "tier": "medium"
    },
    {
      "factor": "obesity",
      "points": 0,
      "present": false,
      "tier": "medium"
    }
  ],
  "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": "Lyon AR, Dent S, Stanway S, et al.",
    "doi": "10.1002/ejhf.1920",
    "id": "lyon-2020",
    "pmid": "32458582",
    "source": "Eur J Heart Fail. 2020;22(11):1945-1960",
    "title": "Baseline cardiovascular risk assessment in cancer patients scheduled to receive cardiotoxic cancer therapies: a position statement and new risk assessment tools from the Cardio-Oncology Study Group of the Heart Failure Association of the European Society of Cardiology in collaboration with the International Cardio-Oncology Society"
  },
  "formula": "hfa_icos_raf_mek",
  "formula_expression": "HFA-ICOS RAF-MEK (Lyon 2020): very_high if heart_failure_or_cardiomyopathy; high if mi_or_cabg or stable_angina or severe_valvular_heart_disease or prior_anthracycline or medium_points>=5; medium if medium_points 2-4; low if medium_points 0-1; medium_points = M2 (lvef 50-54, elevated_troponin, elevated_bnp, hypertension, prior_left_chest_or_mediastinal_rt) + M1 (arrhythmia, age>=65, diabetes, ckd, current_or_significant_smoker, obesity); LVEF <50 is not a printed High row on this table; age>=65 Medium 1 only (no High age band); cardiotoxicity_guide low <2%, medium 2-9%, high 10-19%, very_high >=20%",
  "age_years": 50,
  "cardiotoxicity_guide": "<2%",
  "lvef_percent": 60,
  "medium_points": 0,
  "risk_level": "low"
}
```

## Errors

- HTTP 400 `invalid_hfa_icos_raf_mek`: Lyon 2020 HFA-ICOS RAF-MEK inhibitor inputs must match that table's age, LVEF, and yes/no factors. 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

- [HFA-ICOS anthracycline baseline CV risk](https://magentlab.com/docs/hfa-icos-anthracycline) — Apply the Lyon 2020 HFA-ICOS anthracycline baseline cardiovascular risk proforma from caller-assigned age, LVEF, and published Very high, High, Medium 2, and Medium 1 factors. Returns risk_level, medium_points, and the paper's expert-opinion cardiotoxicity_guide.
- [NYHA](https://magentlab.com/docs/nyha) — Return the 1994 NYHA functional capacity class 1-4 from a caller-assigned integer, with the published class description.
- [MAGGIC](https://magentlab.com/docs/maggic) — Sum the Pocock 2013 MAGGIC integer chart from thirteen caller-supplied heart-failure predictors and return the published Table 4 1-year and 3-year death probabilities for scores 0-50.
- [HCM Risk-SCD](https://magentlab.com/docs/hcm-risk-scd) — Compute the O'Mahony 2014 HCM Risk-SCD 5-year sudden cardiac death probability from maximal wall thickness, left-atrial diameter, maximal LVOT gradient, family history of SCD, NSVT, unexplained syncope, and age.

## 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.