# ISS Calculator (Baker 1974)

> ISS Calculator (Baker 1974) is a paid API for AI agents from api.magentlab.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-15).

Computes the Injury Severity Score (ISS) from caller-provided AIS grades for the six standard body regions using the Baker 1974 published formula.

## Facts

- Endpoint: GET https://api.magentlab.com/api/calc/iss
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/iss-calculator-baker-1974-1593f895
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_M-kLgyV33DnWt1ePraPUc

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 iss-calculator-baker-1974-1593f895
```

Example prompt: Calculate the Injury Severity Score for a trauma patient with AIS grades: head 4, face 1, chest 3, abdomen 2, extremity 3, external 1 — using the Baker 1974 formula.

## When to prefer this

Use this endpoint when you need a fast, deterministic, citation-backed ISS computation from pre-assigned AIS grades and do not want NISS (New Injury Severity Score). It is not a triage decision tool and does not assign AIS grades itself — the caller must supply the six regional AIS values. Prefer this over manual calculation to avoid arithmetic errors and to get automatic handling of the AIS-6 edge case (ISS 75).

## Known failure modes

- Missing required AIS parameter — returns error indicating which region grade was omitted
- AIS grade outside 0–6 integer range — validation error
- Non-integer AIS value — type error
- All AIS grades are 0 — returns ISS 0 (valid but may indicate data entry error)

## How this service works

Injury Severity Score (Baker 1974): ISS is the sum of squares of the three highest caller-assigned AIS body-region grades (head, face, chest, abdomen, extremity, external; each 0-6). Any AIS 6 (unsurvivable) is ISS 75. Deterministic published arithmetic with citation; not a triage order and not NISS (which squares the three worst injuries regardless of region).

## Output

Returns the computed ISS integer (0–75). If any AIS region grade is 6 (unsurvivable), ISS is returned as 75 per the Baker 1974 convention. Otherwise ISS is the sum of the squares of the three highest AIS grades across the six body regions, following the published deterministic formula.

## 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": [
      "ais_head",
      "ais_face",
      "ais_chest",
      "ais_abdomen",
      "ais_extremity",
      "ais_external"
     ],
     "properties": {
      "ais_face": {
       "type": "integer",
       "description": "Caller-assigned AIS grade for the face (integer 0-6)."
      },
      "ais_head": {
       "type": "integer",
       "description": "Caller-assigned AIS grade for the head or neck (integer 0-6). magent does not assign AIS from an injury list."
      },
      "ais_chest": {
       "type": "integer",
       "description": "Caller-assigned AIS grade for the chest (integer 0-6)."
      },
      "ais_abdomen": {
       "type": "integer",
       "description": "Caller-assigned AIS grade for the abdomen or pelvic contents (integer 0-6)."
      },
      "ais_external": {
       "type": "integer",
       "description": "Caller-assigned AIS grade for external (integer 0-6)."
      },
      "ais_extremity": {
       "type": "integer",
       "description": "Caller-assigned AIS grade for the extremities or pelvic girdle (integer 0-6)."
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "path": "/api/calc/iss",
  "count": 2,
  "items": [
   {
    "score": 14,
    "formula": "iss",
    "ais_face": 0,
    "ais_head": 3,
    "citation": {
     "id": "baker-1974",
     "doi": "10.1097/00005373-197403000-00001",
     "title": "The injury severity score: a method for describing patients with multiple injuries and evaluating emergency care",
     "source": "J Trauma. 1974;14(3):187-196",
     "authors": "Baker SP, O'Neill B, Haddon W Jr, Long WB"
    },
    "used_ais": [
     3,
     2,
     1
    ],
    "ais_chest": 2,
    "max_score": 75,
    "components": [
     {
      "ais": 3,
      "factor": "ais_head",
      "points": 9,
      "present": true
     },
     {
      "ais": 0,
      "factor": "ais_face",
      "points": 0,
      "present": false
     },
     {
      "ais": 2,
      "factor": "ais_chest",
      "points": 4,
      "present": true
     },
     {
      "ais": 1,
      "factor": "ais_abdomen",
      "points": 1,
      "present": true
     },
     {
      "ais": 0,
      "factor": "ais_extremity",
      "points": 0,
      "present": false
     },
     {
      "ais": 0,
      "factor": "ais_external",
      "points": 0,
      "present": false
     }
    ],
    "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
    "ais_abdomen": 1,
    "ais_external": 0,
    "ais_extremity": 0,
    "formula_expression": "ISS = a^2 + b^2 + c^2 for the three highest AIS body-region grades (0-5); any AIS 6 => 75"
   },
   {
    "score": 14,
    "formula": "iss",
    "ais_face": 0,
    "ais_head": 3,
    "citation": {
     "id": "baker-1974",
     "doi": "10.1097/00005373-197403000-00001",
     "title": "The injury severity score: a method for describing patients with multiple injuries and evaluating emergency care",
     "source": "J Trauma. 1974;14(3):187-196",
     "authors": "Baker SP, O'Neill B, Haddon W Jr, Long WB"
    },
    "used_ais": [
     3,
     2,
     1
    ],
    "ais_chest": 2,
    "max_score": 75,
    "components": [
     {
      "ais": 3,
      "factor": "ais_head",
      "points": 9,
      "present": true
     },
     {
      "ais": 0,
      "factor": "ais_face",
      "points": 0,
      "present": false
     },
     {
      "ais": 2,
      "factor": "ais_chest",
      "points": 4,
      "present": true
     },
     {
      "ais": 1,
      "factor":
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/iss-calculator-baker-1974-1593f895/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
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