# Magent Static Respiratory Compliance (Cstat) Calculator

> Magent Static Respiratory Compliance (Cstat) Calculator 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).

Calculates static respiratory system compliance (Cstat in mL/cm H₂O) using the ARDS Network 2000 formula: Cstat = tidal_volume_ml / (pplat_cm_h2o - peep_cm_h2o)

## Facts

- Endpoint: GET https://api.magentlab.com/api/calc/cstat
- 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/magent-static-respiratory-compliance-cstat-calculator-3d4639bd
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_au9FO24KiYpw1tXUAcx0-

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 magent-static-respiratory-compliance-cstat-calculator-3d4639bd
```

Example prompt: Calculate the static respiratory compliance for my ICU patient who has a tidal volume of 450 mL, a plateau pressure of 28 cm H2O, and a PEEP of 8 cm H2O using the ARDS Network formula.

## When to prefer this

Use this endpoint when you need a single, standards-based static compliance calculation following the exact ARDS Network 2000 methodology and you already have the three measured ventilator values in hand. Prefer it over manual calculation to avoid arithmetic errors and to get consistent, validated results. Do not use if you need dynamic compliance, Murray Score ARDS severity banding, or if you expect the service to read ventilator data directly.

## Known failure modes

- Pplat ≤ PEEP: request rejected as physiologically invalid (cannot divide by zero or negative)
- tidal_volume_ml outside 50–2000 mL range: clamped or rejected
- pplat_cm_h2o outside 5–80 cm H2O range: clamped or rejected
- peep_cm_h2o outside 0–40 cm H2O range: clamped or rejected
- missing required query parameters: HTTP 400 or validation error
- payment not provided or insufficient: HTTP 402

## How this service works

Static respiratory-system compliance (Cstat) as in ARDS Network 2000 methods: Cstat (mL/cm H2O) = tidal_volume_ml / (pplat_cm_h2o - peep_cm_h2o). Caller supplies the three measured terms. Rejects Pplat less than or equal to PEEP. Does not invent ARDS severity bands from Cstat (Murray 1988 compliance bands are a different tool). Not a ventilator order or medical device. magent does not read the ventilator.

## Output

Returns a numeric Cstat value in mL/cm H2O computed as tidal_volume_ml divided by (pplat_cm_h2o minus peep_cm_h2o). Returns an error or rejection if plateau pressure is less than or equal to PEEP, or if input values fall outside clamped physiologic ranges.

## 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": [
      "tidal_volume_ml",
      "pplat_cm_h2o",
      "peep_cm_h2o"
     ],
     "properties": {
      "peep_cm_h2o": {
       "type": "number",
       "description": "Positive end-expiratory pressure in cm H2O (0-40, magent clamp). Must be less than plateau pressure. magent does not read the ventilator."
      },
      "pplat_cm_h2o": {
       "type": "number",
       "description": "End-inspiratory plateau pressure in cm H2O (5-80, magent clamp). Must be greater than PEEP. magent does not read the ventilator."
      },
      "tidal_volume_ml": {
       "type": "number",
       "description": "Expired tidal volume in mL (50-2000, magent clamp). Caller supplies the measured term. magent does not read the ventilator."
      }
     }
    }
   },
   "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/magent-static-respiratory-compliance-cstat-calculator-3d4639bd/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)