# Harvey-Bradshaw Index (HBI) Calculator

> Harvey-Bradshaw Index (HBI) Calculator is a paid API for AI agents from api.magentlab.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-13).

Calculates the Harvey-Bradshaw simple Crohn's Disease Activity Index score from one day of symptom and complication data

## Facts

- Endpoint: GET https://api.magentlab.com/api/calc/harvey_bradshaw
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/harvey-bradshaw-index-hbi-calculator-ccff3adb
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_AD2NfnshSqpVnCq10cviw

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 harvey-bradshaw-index-hbi-calculator-ccff3adb
```

Example prompt: Calculate the Harvey-Bradshaw Index for a Crohn's patient who rates their well-being as 2 (poor), abdominal pain as 1 (mild), had 4 liquid stools yesterday, abdominal mass score 0, with arthralgia present but no other complications.

## When to prefer this

Use this endpoint when you need a fast, deterministic computation of the Harvey-Bradshaw simple Crohn's Disease Activity Index from a single day of patient-reported or clinician-recorded data. Prefer this over manual calculation when building clinical decision support tools, patient monitoring apps, or research pipelines. Do not use for the full Best 1976 CDAI (which requires 7-day data), for diagnosis, or for determining remission thresholds beyond the raw score.

## Known failure modes

- Missing required query parameters returns an error
- Out-of-range integer values (e.g. well_being > 4 or liquid_stools > 30) may be rejected or clamped
- Non-boolean values passed for complication flags cause validation errors
- Network or payment-related failures (x402 payment not accepted) block the response

## How this service works

Harvey and Bradshaw 1980 simple Crohn's-disease activity index (one-day; items 1-3 previous day). Well-being 0-4, abdominal pain 0-3, liquid stools (1 point each; magent clamp 0-30), abdominal mass 0-3, plus 1 per listed complication (arthralgia, uveitis, erythema nodosum, aphthous ulcers, pyoderma gangrenosum, anal fissure, new fistula, abscess). magent sums only (max 48) and does not return later remission cutoffs. Not a Crohn's diagnosis or Best 1976 CDAI. magent does not examine the patient.

## Output

A numeric Harvey-Bradshaw Index (HBI) total score between 0 and 48 (maximum), computed by summing: well-being (0–4), abdominal pain (0–3), one point per liquid stool (clamped at 30), abdominal mass (0–3), and one point per present complication (arthralgia, uveitis, erythema nodosum, aphthous ulcers, pyoderma gangrenosum, anal fissure, new fistula, abscess). The endpoint does not provide a remission classification or diagnosis.

## 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": [
      "well_being",
      "abdominal_pain",
      "liquid_stools",
      "abdominal_mass",
      "arthralgia",
      "uveitis",
      "erythema_nodosum",
      "aphthous_ulcers",
      "pyoderma_gangrenosum",
      "anal_fissure",
      "new_fistula",
      "abscess"
     ],
     "properties": {
      "abscess": {
       "type": "boolean",
       "description": "Abscess present (Harvey 1980 complications as used for the simple index). true or false. 1 point if true. magent does not examine the patient."
      },
      "uveitis": {
       "type": "boolean",
       "description": "Uveitis present (Harvey 1980 complications as used for the simple index). true or false. 1 point if true. magent does not examine the patient."
      },
      "arthralgia": {
       "type": "boolean",
       "description": "Arthralgia present (Harvey 1980 complications as used for the simple index). true or false. 1 point if true. magent does not examine the patient."
      },
      "well_being": {
       "type": "integer",
       "description": "Caller-assigned Harvey 1980 general well-being for the previous day (integer 0-4): 0 very well; 1 slightly below par; 2 poor; 3 very poor; 4 terrible. magent does not examine the patient."
      },
      "new_fistula": {
       "type": "boolean",
       "description": "New fistula present (Harvey 1980 complications as used for the simple index). true or false. 1 point if true. magent does not examine the patient."
      },
      "anal_fissure": {
       "type": "boolean",
       "description": "Anal fissure present (Harvey 1980 complications as used for the simple index). true or false. 1 point if true. magent does not examine the patient."
      },
      "liquid_stools": {
       "type": "integer",
       "description": "Count of liquid stools that day (Harvey 1980; 1 point per stool). Integer 0-30 is a magent clamp, not a published maximum. magent does not examine the patien
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/harvey-bradshaw-index-hbi-calculator-ccff3adb/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)