# Behavioral Pain Scale (BPS) Calculator — Payen 2001

> Behavioral Pain Scale (BPS) Calculator — Payen 2001 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 Payen 2001 Behavioral Pain Scale (BPS) score by summing three caller-supplied integer items (facial expression, upper limbs, ventilator compliance), each rated 1–4, yielding a total of 3–12.

## Facts

- Endpoint: GET https://api.magentlab.com/api/calc/bps
- 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/behavioral-pain-scale-bps-calculator-payen-2001-8d1276d5
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_MBPapiSROflqHHjpM64yI

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 behavioral-pain-scale-bps-calculator-payen-2001-8d1276d5
```

Example prompt: Calculate the Payen 2001 BPS score for my ICU patient: facial expression is partially tightened (score 2), upper limbs are partially bent (score 2), and ventilator compliance is coughing but tolerating most of the time (score 2).

## When to prefer this

Use this endpoint when you need a fast, deterministic arithmetic computation of the Payen 2001 BPS score from pre-assessed subscores and want to avoid manual summation errors in an automated ICU documentation or clinical decision-support pipeline. Prefer this over CPOT calculators (which use 0–2 subscores) or any endpoint that claims to observe or diagnose the patient directly.

## Known failure modes

- Integer values outside 1–4 range for any item will cause a validation error
- Missing any of the three required query parameters returns an error
- Non-integer (float or string) inputs for subscores will be rejected
- Score interpretation (e.g. pain-present cutoff) is not provided — callers must apply their own clinical thresholds

## How this service works

Payen 2001 Behavioral Pain Scale from three caller-assigned 1-4 items (facial_expression, upper_limbs, ventilator_compliance) using that paper's Table 1 descriptors. magent sums only (range 3-12) and does not observe the patient. No later pain-present cutoffs. Not a pain diagnosis or analgesic order. Not CPOT (CPOT items are 0-2).

## Output

Returns the summed Behavioral Pain Scale total score as an integer between 3 and 12, derived strictly from the three caller-provided subscores using Payen 2001 Table 1 definitions. No pain diagnosis, cutoff interpretation, or analgesic recommendation is included.

## 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": [
      "facial_expression",
      "upper_limbs",
      "ventilator_compliance"
     ],
     "properties": {
      "upper_limbs": {
       "type": "integer",
       "description": "Caller-assigned Payen 2001 BPS upper limbs (integer 1-4): 1 no movement; 2 partially bent; 3 fully bent with finger flexion; 4 permanently retracted. magent does not observe the patient."
      },
      "facial_expression": {
       "type": "integer",
       "description": "Caller-assigned Payen 2001 BPS facial expression (integer 1-4): 1 relaxed; 2 partially tightened (e.g. brow lowering); 3 fully tightened (e.g. eyelid closing); 4 grimacing. magent does not observe the patient."
      },
      "ventilator_compliance": {
       "type": "integer",
       "description": "Caller-assigned Payen 2001 BPS compliance with ventilation (integer 1-4): 1 tolerating movement; 2 coughing but tolerating ventilation most of the time; 3 fighting ventilator; 4 unable to control ventilation. magent does not observe the patient."
      }
     }
    }
   },
   "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/behavioral-pain-scale-bps-calculator-payen-2001-8d1276d5/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)