# Magent Rule of Nines TBSA Calculator

> Magent Rule of Nines TBSA 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 adult total body surface area (TBSA) burned percentage using the Wallace 1951 Rule of Nines, given caller-assigned involvement fractions for eight anatomical regions.

## Facts

- Endpoint: GET https://api.magentlab.com/api/calc/rule_of_nines
- 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-rule-of-nines-tbsa-calculator-ecd7ac06
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_E_Sr1FaTm8PV6EZCnRF7f

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-rule-of-nines-tbsa-calculator-ecd7ac06
```

Example prompt: Calculate the Rule of Nines TBSA burned for an adult patient whose entire head is involved, both arms are fully burned, the anterior trunk is half involved, the posterior trunk is not involved, both legs are fully burned, and the perineum is not involved.

## When to prefer this

Use this endpoint when you need a fast, standardized adult Wallace 1951 Rule of Nines TBSA calculation and the caller is responsible for assessing region involvement. It is NOT suitable for pediatric patients (use Lund-Browder for children), does not perform clinical burn examination, and does not output Parkland fluid volumes (use a separate Parkland endpoint with tbsa_percent as input).

## Known failure modes

- Missing any of the eight required query parameters returns a validation error
- Invalid fraction values outside the allowed enum (0, 0.5, 1) are rejected
- Network or payment failure (402 x402 protocol) if USDC payment is not attached

## How this service works

Adult Wallace 1951 rule of nines: percent TBSA from eight region fractions (0 none, 0.5 half, 1 full) using head 9, each arm 9, anterior trunk 18, posterior trunk 18, each leg 18, perineum 1. magent does not examine the burn. Not Lund-Browder and not a Parkland fluid order (Parkland takes tbsa_percent separately).

## Output

Returns the calculated total body surface area (TBSA) burned as a percentage, derived by summing the Wallace 1951 regional weights (head 9%, each arm 9%, anterior trunk 18%, posterior trunk 18%, each leg 18%, perineum 1%) multiplied by the caller-supplied involvement fractions (0, 0.5, or 1) for each region.

## 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": [
      "head",
      "arm_left",
      "arm_right",
      "anterior_trunk",
      "posterior_trunk",
      "leg_left",
      "leg_right",
      "perineum"
     ],
     "properties": {
      "head": {
       "enum": [
        0,
        0.5,
        1
       ],
       "type": "number",
       "description": "Caller-assigned Wallace 1951 adult head involvement (0 none, 0.5 half, 1 full). Full involvement is 9%. magent does not examine the burn."
      },
      "arm_left": {
       "enum": [
        0,
        0.5,
        1
       ],
       "type": "number",
       "description": "Caller-assigned Wallace 1951 adult arm_left involvement (0 none, 0.5 half, 1 full). Full involvement is 9%. magent does not examine the burn."
      },
      "leg_left": {
       "enum": [
        0,
        0.5,
        1
       ],
       "type": "number",
       "description": "Caller-assigned Wallace 1951 adult leg_left involvement (0 none, 0.5 half, 1 full). Full involvement is 18%. magent does not examine the burn."
      },
      "perineum": {
       "enum": [
        0,
        0.5,
        1
       ],
       "type": "number",
       "description": "Caller-assigned Wallace 1951 adult perineum involvement (0 none, 0.5 half, 1 full). Full involvement is 1%. magent does not examine the burn."
      },
      "arm_right": {
       "enum": [
        0,
        0.5,
        1
       ],
       "type": "number",
       "description": "Caller-assigned Wallace 1951 adult arm_right involvement (0 none, 0.5 half, 1 full). Full involvement is 9%. magent does not examine the burn."
      },
      "leg_right": {
       "enum": [
        0,
        0.5,
        1
       ],
       "type": "number",
       "description": "Caller-assigned Wallace 1951 adult leg_right involvement (0 none, 0.5 half, 1 full). Full involvement is 18%. magent does not examine the burn."
      },
      "anterior_trunk": {
       "enum": [
        0,
     
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/magent-rule-of-nines-tbsa-calculator-ecd7ac06/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)