# CHADS-65 Stroke Prevention Algorithm for Nonvalvular AF/AFL

> CHADS-65 Stroke Prevention Algorithm for Nonvalvular AF/AFL is a paid API for AI agents from api.magentlab.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-14).

Applies the CCS 2014 CHADS-65 algorithm to recommend oral anticoagulant, aspirin, or no therapy for stroke prevention in nonvalvular atrial fibrillation or flutter.

## Facts

- Endpoint: GET https://api.magentlab.com/api/calc/chads_65
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/chads-65-stroke-prevention-algorithm-for-nonvalvular-af-afl-3cf8acbe
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_mNghEidRF1BH7KBk1zXOx

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability chads-65-stroke-prevention-algorithm-for-nonvalvular-af-afl-3cf8acbe
```

Example prompt: My patient is 68 years old with a history of hypertension and diabetes but no prior stroke, no CHF, and no vascular disease — run the CHADS-65 algorithm to see whether they need oral anticoagulation or aspirin for their nonvalvular atrial fibrillation.

## When to prefer this

Choose this endpoint when you need to apply specifically the CCS 2014 CHADS-65 guideline for nonvalvular AF or AFL stroke prevention triage — not CHADS2, CHA2DS2-VASc, or HAS-BLED. Ideal for Canadian guideline-aligned clinical decision support tools or educational discussion aids.

## Known failure modes

- Missing required query parameters (age, chf, hypertension, diabetes, stroke_tia, vascular_disease) returns a validation error
- Age outside integer range 18–120 may produce unexpected results or rejection
- Boolean fields passed as non-boolean strings may fail schema validation
- Payment failure (HTTP 402) if USDC payment is not provided or is insufficient

## How this service works

CCS 2014 CHADS-65 algorithm for nonvalvular AF/AFL stroke-prevention discussion. Oral anticoagulant if age ≥65 or CHF, hypertension, diabetes, or prior stroke/TIA. Else aspirin if coronary, aortic, or peripheral arterial disease. Else none. Not CHADS2, not CHA2DS2-VASc, not HAS-BLED, and not an anticoagulation order. magent does not examine the patient.

## Output

Returns the CHADS-65 algorithm recommendation: oral anticoagulant (OAC) if age ≥65 or any of CHF, hypertension, diabetes, or prior stroke/TIA are present; aspirin if OAC is not indicated but vascular disease is present; or no antithrombotic therapy if none of the above criteria apply. This is a discussion aid, not a clinical order.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "headers": {
     "type": "object",
     "additionalProperties": {
      "type": "string"
     }
    },
    "queryParams": {
     "type": "object",
     "required": [
      "age",
      "chf",
      "hypertension",
      "diabetes",
      "stroke_tia",
      "vascular_disease"
     ],
     "properties": {
      "age": {
       "type": "integer",
       "description": "Age in years (18-120). ≥65 indicates oral anticoagulant (OAC). Age ≥75 is subsumed by ≥65; there is no separate age≥75 input. 64 does not indicate OAC on age alone."
      },
      "chf": {
       "type": "boolean",
       "description": "Congestive heart failure as assigned by the caller. true or false. Any true CHADS2 factor other than age≥75 (CHF, hypertension, diabetes, prior stroke/TIA) indicates OAC."
      },
      "diabetes": {
       "type": "boolean",
       "description": "Diabetes mellitus as assigned by the caller. true or false. Indicates OAC when true."
      },
      "stroke_tia": {
       "type": "boolean",
       "description": "Prior stroke or TIA as assigned by the caller. true or false. Indicates OAC when true."
      },
      "hypertension": {
       "type": "boolean",
       "description": "Hypertension history as assigned by the caller. true or false. Indicates OAC when true."
      },
      "vascular_disease": {
       "type": "boolean",
       "description": "Coronary, aortic, or peripheral arterial disease as assigned by the caller. true or false. Indicates ASA only when OAC is not indicated."
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/chads-65-stroke-prevention-algorithm-for-nonvalvular-af-afl-3cf8acbe/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.magentlab.com](https://www.zero.xyz/host/api.magentlab.com/llms.txt)