# Pre-endoscopy Rockall

Pre-endoscopy Rockall

Status: LIVE
Price: $0.005 USDC
`GET /api/calc/rockall_pre`
HTML: https://magentlab.com/docs/rockall-pre
Markdown: https://magentlab.com/docs/rockall-pre.md

Not a medical device. Not a diagnosis, dose, or listing recommendation.

## What it computes

Compute the Rockall 1996 pre-endoscopy (admission) score from age, heart rate, systolic blood pressure, and caller-assigned comorbidity after acute upper gastrointestinal haemorrhage.

## When to use

When an agent needs the published pre-endoscopy Rockall score (age + shock + comorbidity only) and must not apply complete/post-endoscopy Rockall, AIMS65, or Glasgow-Blatchford.

## When not to use

- Not a diagnosis of the cause or severity of bleeding.
- Not complete or post-endoscopy Rockall. This tool is the admission/pre-endoscopy score only (age, shock, and comorbidity). Diagnosis and stigmata of recent haemorrhage are not inputs.
- Not AIMS65 and not the Glasgow-Blatchford score.
- magent does not assign comorbidity. The caller maps cardiac failure, IHD, or any major comorbidity to cardiac, and renal failure, liver failure, or disseminated malignancy to renal_liver_metastatic.

## Formula

```
pre-endoscopy Rockall = age (<60: 0, 60-79: 1, >=80: 2) + shock (SBP<100: 2; else HR>=100: 1; else 0) + comorbidity (none: 0, cardiac: 2, renal_liver_metastatic: 3); max 7
```

## Citation

[Risk assessment after acute upper gastrointestinal haemorrhage](https://doi.org/10.1136/gut.38.3.316)
Rockall TA, Logan RF, Devlin HB, Northfield TC
Gut. 1996;38(3):316-321
DOI: [10.1136/gut.38.3.316](https://doi.org/10.1136/gut.38.3.316)

## Worked example

### Age 50, no shock, no comorbidity

Given: `age=50, comorbidity=none, heart_rate_bpm=80, systolic_mm_hg=120`

1. Age 50 is <60 → 0; HR 80 with SBP 120 is not tachycardia or hypotension → 0; comorbidity none → 0
2. Score = 0 (max 7)


### Age 80, hypotension, renal/liver/metastatic (max 7)

Given: `age=80, comorbidity=renal_liver_metastatic, heart_rate_bpm=60, systolic_mm_hg=99`

1. Age 80 ≥ 80 → 2; SBP 99 < 100 → 2 (hypotension; tachycardia not added); renal_liver_metastatic → 3
2. Score = 7 (max 7)


## Also searched as

- pre-endoscopy Rockall
- admission Rockall score
- Rockall 1996
- clinical Rockall
- pre endoscopy Rockall
- Rockall GI bleed score

## Parameters

- `age` (integer, required): Age in years (18-120). <60 scores 0; 60-79 scores 1; ≥80 scores 2. 59 does not score; 60 scores 1; 79 scores 1; 80 scores 2.
- `heart_rate_bpm` (integer, required): Heart rate in beats per minute (integer 30-220). With SBP ≥100, HR ≥100 scores 1 (tachycardia); 99 does not. Not added when SBP <100.
- `systolic_mm_hg` (number, required): Systolic blood pressure in mm Hg (50-250). SBP <100 scores 2 (hypotension) and tachycardia is not added; 100 does not score hypotension.
- `comorbidity` (string, required): Caller-assigned comorbidity: none (0), cardiac (2; cardiac failure, IHD, or any major comorbidity), or renal_liver_metastatic (3; renal failure, liver failure, or disseminated malignancy). magent does not assign comorbidity.

## Bulk (POST)

POST the same path with a JSON items array. Price is n times the GET unit. Invalid items return HTTP 400 before settlement.

Method: `POST /api/calc/rockall_pre`
Max items: 25
Price: unit_amount * n (unit 5000 atomic)
Status: PREVIEW

- 1 to 25 items. Each item uses the same keys as the GET query parameters.
- The first invalid item fails the whole request (index in the 400 JSON). You are not charged.
- HTTP 200 is {count, path, items}. Each items[i] is the GET 200 body for that row.
- Catalog misses (empty matches, found=false) stay paid 200s inside that slot.
- x402 resource URL is this path plus n and body_sha256. Browsers that prefer text/html get the same paywall as GET; Pay retries POST with the same items.

Example request:

```json
{
  "items": [
    {
      "age": "50",
      "comorbidity": "none",
      "heart_rate_bpm": "80",
      "systolic_mm_hg": "120"
    },
    {
      "age": "50",
      "comorbidity": "none",
      "heart_rate_bpm": "80",
      "systolic_mm_hg": "120"
    }
  ]
}
```

Human paywall (two-item fixture): https://api.magentlab.com/paywall/bulk/rockall-pre

Example 200:

```json
{
  "count": 2,
  "path": "/api/calc/rockall_pre",
  "items": [
    {
      "components": [
        {
          "value": 50,
          "factor": "age",
          "points": 0,
          "present": false
        },
        {
          "value": {
            "systolic_mm_hg": 120.0,
            "heart_rate_bpm": 80
          },
          "factor": "shock",
          "points": 0,
          "present": false
        },
        {
          "value": "none",
          "factor": "comorbidity",
          "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.",
      "citation": {
        "authors": "Rockall TA, Logan RF, Devlin HB, Northfield TC",
        "doi": "10.1136/gut.38.3.316",
        "id": "rockall-1996",
        "source": "Gut. 1996;38(3):316-321",
        "title": "Risk assessment after acute upper gastrointestinal haemorrhage"
      },
      "formula": "rockall_pre",
      "formula_expression": "pre-endoscopy Rockall = age (<60: 0, 60-79: 1, >=80: 2) + shock (SBP<100: 2; else HR>=100: 1; else 0) + comorbidity (none: 0, cardiac: 2, renal_liver_metastatic: 3); max 7",
      "max_score": 7,
      "score": 0,
      "age_years": 50,
      "systolic_mm_hg": 120.0,
      "heart_rate_bpm": 80,
      "comorbidity": "none"
    },
    {
      "components": [
        {
          "value": 50,
          "factor": "age",
          "points": 0,
          "present": false
        },
        {
          "value": {
            "systolic_mm_hg": 120.0,
            "heart_rate_bpm": 80
          },
          "factor": "shock",
          "points": 0,
          "present": false
        },
        {
          "value": "none",
          "factor": "comorbidity",
          "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.",
      "citation": {
        "authors": "Rockall TA, Logan RF, Devlin HB, Northfield TC",
        "doi": "10.1136/gut.38.3.316",
        "id": "rockall-1996",
        "source": "Gut. 1996;38(3):316-321",
        "title": "Risk assessment after acute upper gastrointestinal haemorrhage"
      },
      "formula": "rockall_pre",
      "formula_expression": "pre-endoscopy Rockall = age (<60: 0, 60-79: 1, >=80: 2) + shock (SBP<100: 2; else HR>=100: 1; else 0) + comorbidity (none: 0, cardiac: 2, renal_liver_metastatic: 3); max 7",
      "max_score": 7,
      "score": 0,
      "age_years": 50,
      "systolic_mm_hg": 120.0,
      "heart_rate_bpm": 80,
      "comorbidity": "none"
    }
  ]
}
```

## Response fields

- `formula` (string): rockall_pre
- `formula_expression` (string): Exact expression used
- `score` (integer): Total points 0-7
- `max_score` (integer): Always 7
- `age_years` (integer): Age used for the age band
- `heart_rate_bpm` (integer): Heart rate used, bpm
- `systolic_mm_hg` (number): Systolic pressure used, mm Hg
- `comorbidity` (string): none, cardiac, or renal_liver_metastatic as supplied by the caller
- `components` (array): Age, shock, and comorbidity points
- `citation` (object): Rockall 1996 citation
- `disclaimer` (string): Not-a-device notice

## Example JSON

Frozen fixture. Not a live lookup.

```json
{
  "components": [
    {
      "value": 50,
      "factor": "age",
      "points": 0,
      "present": false
    },
    {
      "value": {
        "systolic_mm_hg": 120.0,
        "heart_rate_bpm": 80
      },
      "factor": "shock",
      "points": 0,
      "present": false
    },
    {
      "value": "none",
      "factor": "comorbidity",
      "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.",
  "citation": {
    "authors": "Rockall TA, Logan RF, Devlin HB, Northfield TC",
    "doi": "10.1136/gut.38.3.316",
    "id": "rockall-1996",
    "source": "Gut. 1996;38(3):316-321",
    "title": "Risk assessment after acute upper gastrointestinal haemorrhage"
  },
  "formula": "rockall_pre",
  "formula_expression": "pre-endoscopy Rockall = age (<60: 0, 60-79: 1, >=80: 2) + shock (SBP<100: 2; else HR>=100: 1; else 0) + comorbidity (none: 0, cardiac: 2, renal_liver_metastatic: 3); max 7",
  "max_score": 7,
  "score": 0,
  "age_years": 50,
  "systolic_mm_hg": 120.0,
  "heart_rate_bpm": 80,
  "comorbidity": "none"
}
```

## Errors

- HTTP 400 `invalid_age`: age must be an integer from 18 to 120 Returned before settlement; you are not charged.
- HTTP 400 `invalid_heart_rate`: heart_rate_bpm must be an integer from 30 to 220 Returned before settlement; you are not charged.
- HTTP 400 `invalid_systolic_bp`: systolic_mm_hg or systolic_bp_mm_hg must be a number from 50 to 250. Returned before settlement; you are not charged.
- HTTP 400 `invalid_rockall_comorbidity`: comorbidity must be none, cardiac, or renal_liver_metastatic. Returned before settlement; you are not charged.
- HTTP 400 `invalid_items`: POST body must be a JSON object with only an items array Returned before settlement; you are not charged.
- HTTP 400 `invalid_item_count`: items must be an array of 1 to 25 objects Returned before settlement; you are not charged.
- HTTP 400 `invalid_item`: each items entry must be a JSON object Returned before settlement; you are not charged.

Shared HTTP 402 and 503: https://magentlab.com/docs/payments

## Related tools

- [Glasgow-Blatchford score](https://magentlab.com/docs/glasgow-blatchford) — Compute the Blatchford 2000 Glasgow-Blatchford score from urea, haemoglobin, systolic BP, heart rate, and four clinical flags.

## Payment

Required query parameters must be present and valid. Invalid params return HTTP 400 JSON before settlement. magent does not charge. Fix the params, then request a new 402 quote for that complete URL. Catalog misses (empty matches, found=false) are valid paid 200s.

- GET the tool with Accept: application/json (do not send Accept: text/html unless you want the human paywall).
- HTTP 402 means you have not paid. Decode the base64 PAYMENT-REQUIRED header. HTTP 503 is not a new quote.
- Sign EIP-3009 (scheme exact, assetTransferMethod eip3009) with validBefore = now + accepts[0].maxTimeoutSeconds (600 seconds). That window starts when you sign and must cover wallet confirmation plus CDP verify and settle. Magent retries transient facilitator 429/5xx before answering. Do not send upto or batch-settlement payloads; magent does not offer those schemes.
- Retry the same URL with PAYMENT-SIGNATURE (base64 JSON echoing accepted, payload, and extensions when present).
- Success is HTTP 200 JSON plus PAYMENT-RESPONSE. Settlement happens before the tool runs. HTTP 503 settlement_uncertain or settle_failed: retry the same PAYMENT-SIGNATURE. Mint a new nonce only after a new HTTP 402.

- offered `exact` on eip155:8453: Fixed-price USDC on Base. The buyer authorizes the advertised amount (EIP-3009). magent settles before the tool runs (paymentFlow upfront). extra.assetTransferMethod=eip3009 extra.paymentFlow=upfront.

- not offered `upto`: Not offered. Usage-based: buyer authorizes a ceiling, seller settles the actual amount after work. Reserved for a future metered tool. Not for current calculators or code search.
- not offered `batch-settlement`: Not offered. Payment-channel vouchers claimed later in batches. Not the same as POST {items} bulk (that is still exact).

Same-path POST {items} is still scheme exact: one EIP-3009 authorization for n times the GET unit. That is not x402 batch-settlement (payment channels / vouchers).

Shared HTTP 402 and 503 table: https://magentlab.com/docs/payments

Stdio MCP (one process per host): https://magentlab.com/docs/mcp

## Guarantees

- Invalid query parameters return HTTP 400 before settlement. You are not charged.
- Settlement finishes before the tool executes (paymentFlow upfront). Uncertain or failed settlement fails closed (HTTP 503). Retry the same PAYMENT-SIGNATURE.
- HTTP 402 is unpaid only. Do not sign a second authorization because of a 503.
- Execution is timeout-bounded and concurrency-capped.
- Calculator inputs are stored encrypted for allowlisted operators (Magent Console). They are not in public logs, SSH lookups, catalog, or rollups. Request logs store path without query.