# SULF-FAST Sulfa Allergy Risk Score Calculator

> SULF-FAST Sulfa Allergy Risk Score 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).

Computes the Waldron 2023 SULF-FAST score to stratify risk in patients reporting a TMP-SMX (sulfa) antibiotic allergy, returning a numeric score and low/elevated risk classification.

## Facts

- Endpoint: GET https://api.magentlab.com/api/calc/sulf_fast
- 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/sulf-fast-sulfa-allergy-risk-score-calculator-60feb983
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_3koJNTYXWWWcQVQSFgdbV

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 sulf-fast-sulfa-allergy-risk-score-calculator-60feb983
```

Example prompt: My patient reports a sulfa allergy from 3 years ago where they had anaphylaxis and required treatment — can you calculate their SULF-FAST score using the Waldron 2023 criteria and tell me if they're low or elevated risk?

## When to prefer this

Use this endpoint when you have a patient with a documented or reported TMP-SMX (sulfa antibiotic) allergy and need a structured, validated risk score based on the Waldron 2023 SULF-FAST criteria. Prefer this over general allergy tools when you specifically need sulfa-adapted PEN-FAST-style scoring. Do not use if the allergy involves penicillin or another drug class — use the appropriate PEN-FAST or drug-specific endpoint instead.

## Known failure modes

- Missing required query parameters (five_or_fewer_years_ago, anaphylaxis_angioedema_or_scar, treatment_required) returns a 400 validation error
- Non-boolean values for flag parameters cause schema validation failure
- Payment not included or insufficient (x402 protocol) returns 402 Payment Required
- Attempting to use this for penicillin allergy or non-sulfa allergy contexts produces a misapplied score — caller must ensure the patient has a reported TMP-SMX allergy

## How this service works

Waldron 2023 SULF-FAST for patients who already report a TMP-SMX (sulfa antibiotic) allergy. Adapted PEN-FAST flags, not PEN-FAST itself. Three caller-assigned flags: allergy event 5 or fewer years ago (2), anaphylaxis/angioedema or potential SCAR as one criterion (2), treatment required (1). Max 5. Risk: low if score < 3, elevated if ≥ 3. low_risk_for_testing iff score < 3. Not an allergy diagnosis or delabeling order. magent does not take an allergy history.

## Output

Returns a SULF-FAST integer score (0–5), a risk category (low if score < 3, elevated if score ≥ 3), and a low_risk_for_testing boolean. This is a clinical decision-support score only — not an allergy diagnosis or a delabeling order.

## 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": [
      "five_or_fewer_years_ago",
      "anaphylaxis_angioedema_or_scar",
      "treatment_required"
     ],
     "properties": {
      "treatment_required": {
       "type": "boolean",
       "description": "Treatment required for the allergy episode as assigned by the caller (Waldron 2023). true scores 1. magent does not take an allergy history."
      },
      "five_or_fewer_years_ago": {
       "type": "boolean",
       "description": "Allergy event 5 or fewer years ago as assigned by the caller (Waldron 2023). true scores 2. magent does not take an allergy history."
      },
      "anaphylaxis_angioedema_or_scar": {
       "type": "boolean",
       "description": "Anaphylaxis/angioedema or potential SCAR as one 2-point criterion (Waldron 2023). true scores 2; do not add both phenotypes separately. magent does not take an allergy history."
      }
     }
    }
   },
   "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/sulf-fast-sulfa-allergy-risk-score-calculator-60feb983/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)