# OS-MRS Obesity Surgery Mortality Risk Score Calculator

> OS-MRS Obesity Surgery Mortality Risk Score 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).

Computes the DeMaria 2007 Obesity Surgery Mortality Risk Score (OS-MRS) from five caller-assigned boolean flags, returning a score (0–5) and risk class (A, B, or C).

## Facts

- Endpoint: GET https://api.magentlab.com/api/calc/os_mrs
- 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/os-mrs-obesity-surgery-mortality-risk-score-calculator-fd5595b2
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_rm-iJ0R76qI5B-agCoX3y

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 os-mrs-obesity-surgery-mortality-risk-score-calculator-fd5595b2
```

Example prompt: Calculate the DeMaria 2007 OS-MRS for a patient who is male, age 48, BMI 52, has hypertension, and no known PE risk factors — what's their risk class?

## When to prefer this

Use this endpoint when you need a deterministic, validated, published clinical score for bariatric surgery mortality risk stratification per DeMaria 2007. Prefer it over manual calculation to ensure correct weighting and class boundaries. Not suitable for estimating actual mortality percentages or for surgical clearance decisions.

## Known failure modes

- Missing required boolean flags returns a validation error
- Non-boolean values for flag parameters cause a 400 error
- Network or payment failure results in no score returned
- All flags false returns score 0, Class A (valid edge case, not an error)

## How this service works

DeMaria 2007 obesity surgery mortality risk score (OS-MRS): five caller-assigned flags (BMI ≥50 kg/m², male, hypertension, known PE risk, age ≥45), 1 point each, max 5. Class A 0–1, B 2–3, C 4–5. Deterministic published score with citation; not a surgical clearance and not a mortality percentage. magent does not weigh the patient or measure age.

## Output

Returns the OS-MRS integer score (0–5), the corresponding risk class (A for 0–1, B for 2–3, C for 4–5), a citation to DeMaria 2007, and a disclaimer that this is not a surgical clearance and does not represent a mortality percentage.

## 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": [
      "bmi_ge_50",
      "male",
      "hypertension",
      "pe_risk_factors",
      "age_ge_45"
     ],
     "properties": {
      "male": {
       "type": "boolean",
       "description": "Male sex (DeMaria 2007). true or false as assigned by the caller. magent does not examine the patient."
      },
      "age_ge_45": {
       "type": "boolean",
       "description": "Age ≥45 years (DeMaria 2007). true or false as assigned by the caller. magent does not measure age."
      },
      "bmi_ge_50": {
       "type": "boolean",
       "description": "BMI ≥50 kg/m² (DeMaria 2007). true or false as assigned by the caller. magent does not weigh the patient or compute BMI."
      },
      "hypertension": {
       "type": "boolean",
       "description": "Hypertension (DeMaria 2007). true or false as assigned by the caller. magent does not measure blood pressure."
      },
      "pe_risk_factors": {
       "type": "boolean",
       "description": "Known PE risk: previous thromboembolism, preoperative vena cava filter, hypoventilation, or pulmonary hypertension (DeMaria 2007). true or false as assigned by the caller."
      }
     }
    }
   },
   "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/os-mrs-obesity-surgery-mortality-risk-score-calculator-fd5595b2/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)