LIVE

CHA2DS2-VASc

Deterministic stroke-risk score from discrete flags. Chest 2010 citation.

LIVE $0.005 USDC GET /api/calc/cha2ds2_vasc

When to use

CHA2DS2-VASc score from discrete clinical flags. Use for stroke-risk stratification arithmetic in atrial fibrillation. Deterministic published score with citation.

Try

Opens the live endpoint. Unpaid browser requests show the paywall; agents should send Accept: application/json.

/api/calc/cha2ds2_vasc?age=78&sex=female&chf=false&hypertension=true&diabetes=true&stroke_tia=false&vascular_disease=false

Full URL: https://api.magentlab.com/api/calc/cha2ds2_vasc?age=78&sex=female&chf=false&hypertension=true&diabetes=true&stroke_tia=false&vascular_disease=false

Request

GET /api/calc/cha2ds2_vasc · x402 V2 · USDC on Base · $0.005 USDC

x402 V2 curl

Expect HTTP 402 and a PAYMENT-REQUIRED header until you retry with PAYMENT-SIGNATURE.

curl -i -H "Accept: application/json" "https://api.magentlab.com/api/calc/cha2ds2_vasc?age=78&sex=female&chf=false&hypertension=true&diabetes=true&stroke_tia=false&vascular_disease=false"

Cursor mcp.json

Intended config for @magent/mcp. This is not npm @x402/fetch (a payment fetch wrapper).

{
  "mcpServers": {
    "magent": {
      "args": [
        "-y",
        "@magent/mcp"
      ],
      "command": "npx",
      "env": {
        "X402_PRIVATE_KEY": "0xYOUR_SPENDING_KEY"
      }
    }
  }
}

Query parameters

Name	Type	Required	Description
`age`	integer	required	Age in years (18-120). ≥75 scores 2; 65-74 scores 1.
`sex`	string	required · female, male	female scores 1 (Sc); male scores 0.
`chf`	boolean	required	Congestive heart failure or LV dysfunction. true or false.
`hypertension`	boolean	required	Hypertension history. true or false.
`diabetes`	boolean	required	Diabetes mellitus. true or false.
`stroke_tia`	boolean	required	Prior stroke, TIA, or thromboembolism. true or false (2 points).
`vascular_disease`	boolean	required	Prior MI, peripheral artery disease, or aortic plaque. true or false.

Success fields

Field	Type	Description
`formula`	string	cha2ds2_vasc
`score`	integer	Total points 0-9
`max_score`	integer	Always 9
`sex`	string	female or male
`age_years`	integer	Age used for A2/A scoring
`components`	array	Per-factor points
`citation`	object	Chest 2010 citation
`disclaimer`	string	Not-a-device notice

Example

Frozen fixture. Not a live lookup.

{
  "components": [
    {
      "factor": "congestive_heart_failure",
      "points": 0,
      "present": false
    },
    {
      "factor": "hypertension",
      "points": 1,
      "present": true
    },
    {
      "value": 78,
      "factor": "age",
      "points": 2,
      "present": true
    },
    {
      "factor": "diabetes",
      "points": 1,
      "present": true
    },
    {
      "factor": "stroke_tia_thromboembolism",
      "points": 0,
      "present": false
    },
    {
      "factor": "vascular_disease",
      "points": 0,
      "present": false
    },
    {
      "factor": "sex_female",
      "points": 1,
      "present": true
    }
  ],
  "disclaimer": "Not a medical device. Deterministic published-formula or coded-ontology output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
  "age_years": 78,
  "citation": {
    "authors": "Lip GYH, Nieuwlaat R, Pisters R, Lane DA, Crijns HJ",
    "doi": "10.1378/chest.09-1584",
    "id": "lip-2010",
    "source": "Chest. 2010;137(2):263-272",
    "title": "Refining clinical risk stratification for predicting stroke and thromboembolism in atrial fibrillation using a novel risk factor-based approach: the euro heart survey on atrial fibrillation"
  },
  "formula": "cha2ds2_vasc",
  "sex": "female",
  "max_score": 9,
  "score": 5
}

Payment

Unpaid requests return HTTP 402 with a base64 PAYMENT-REQUIRED header. Retry the same URL with PAYMENT-SIGNATURE. Settlement completes before the tool runs. Full handshake and shared payment errors: Payments.

Errors

HTTP	Code	When
400	`invalid_age`	age must be an integer from 18 to 120
400	`invalid_sex`	sex must be female or male
400	`invalid_flag`	chf, hypertension, diabetes, stroke_tia, and vascular_disease must be true or false
402	`payment_required`	Missing or invalid PAYMENT-SIGNATURE; decode the PAYMENT-REQUIRED header
409	`payment_in_progress`	The same authorization nonce is already being settled; retry shortly
429	`rate_limited`	Too many requests from this client
503	`settlement_uncertain`	Settlement is unconfirmed; retry with the same PAYMENT-SIGNATURE
503	`facilitator_unavailable`	Payment facilitator unavailable
503	`facilitator_misconfigured`	Payment facilitator is not configured
503	`facilitator_unauthorized`	Payment facilitator rejected credentials
503	`ledger_unavailable`	Payment ledger unavailable
503	`payment_unavailable`	Payment processing unavailable

Guarantees

Settlement finishes before the tool executes. Uncertain settlement fails closed (HTTP 503).
Lookups run on our nodes — no third-party data API wrappers.
Localhost, IP literals, and metadata hostnames are rejected.
Execution is timeout-bounded and concurrency-capped.