# magent BED Calculator (Fowler 1989)

> magent BED Calculator (Fowler 1989) 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).

Calculates Biologically Effective Dose (BED) using the Fowler 1989 formula: BED = n × d × (1 + d / (α/β)), given number of fractions, dose per fraction, and tissue alpha/beta ratio.

## Facts

- Endpoint: GET https://api.magentlab.com/api/calc/bed
- 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/magent-bed-calculator-fowler-1989-a3c25c19
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_e1b0ODcuQIxYVly3xvs7_

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 magent-bed-calculator-fowler-1989-a3c25c19
```

Example prompt: Calculate the BED using the Fowler 1989 formula for 25 fractions of 2 Gy per fraction with an alpha/beta ratio of 10 Gy.

## When to prefer this

Use this endpoint when you need a fast, formula-exact BED computation based strictly on the Fowler 1989 model (no time correction, no repopulation, no EQD2 conversion). Prefer this over general radiobiology tools when you need a lightweight, auditable single-formula result without tissue-table lookups or prescription logic.

## Known failure modes

- Non-positive n or d_gy or alpha_beta — request rejected with error
- n outside 1–50 range — clamped or rejected
- d_gy outside 0.5–30 Gy range — clamped or rejected
- alpha_beta outside 1–20 Gy range — clamped or rejected
- Missing required query parameters — returns validation error
- Payment not included or insufficient — x402 payment required response

## How this service works

Fowler 1989 BED without a time or repopulation term: BED = n * d * (1 + d / (alpha/beta)). n equal fractions (1-50), d Gy per fraction (0.5-30), caller-assigned tissue alpha/beta (1-20 Gy). Rounds to 1 decimal. Rejects non-positive n*d or alpha/beta. No T_k/T_pot, no EQD2. Not a radiotherapy prescription. magent does not plan radiotherapy. Not a medical device.

## Output

Returns a single BED value in Gy, rounded to 1 decimal place, computed as n × d × (1 + d / (α/β)). The API validates inputs and rejects non-positive values for n, d_gy, or alpha_beta, and enforces parameter clamps (n: 1–50, d_gy: 0.5–30, alpha_beta: 1–20).

## 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": [
      "n",
      "d_gy",
      "alpha_beta"
     ],
     "properties": {
      "n": {
       "type": "integer",
       "description": "Number of equal fractions (integer 1-50, magent clamp; Fowler 1989 does not publish an input band). Caller supplies n. magent does not plan a fraction schedule."
      },
      "d_gy": {
       "type": "number",
       "description": "Dose per fraction in Gy (0.5-30, magent clamp). Caller supplies d. magent does not prescribe dose."
      },
      "alpha_beta": {
       "type": "number",
       "description": "Caller-assigned tissue α/β in Gy (1-20, magent clamp). magent does not assign α/β from a tissue table."
      }
     }
    }
   },
   "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/magent-bed-calculator-fowler-1989-a3c25c19/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
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