# Holliday-Segar Maintenance Fluid Calculator

> Holliday-Segar Maintenance Fluid Calculator is a paid API for AI agents from api.magentlab.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-15).

Calculates daily and hourly pediatric/adult maintenance fluid requirements using the Holliday-Segar 1957 method (100/50/20 mL/kg rule) from patient weight in kg or lb

## Facts

- Endpoint: GET https://api.magentlab.com/api/calc/maintenance_fluids
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/holliday-segar-maintenance-fluid-calculator-c9faa02e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_-d6fwDYVt9JhdRwKzyrGW

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 holliday-segar-maintenance-fluid-calculator-c9faa02e
```

Example prompt: Calculate the Holliday-Segar daily and hourly maintenance fluid requirements for a patient who weighs 23 kg.

## When to prefer this

Choose this endpoint when you need a fast, deterministic, citeable Holliday-Segar maintenance fluid calculation from patient weight. Ideal for clinical decision support tools, EHR integrations, or medical education apps that need the published 100/50/20 rule applied precisely. Prefer this over manual calculation to avoid arithmetic errors and to have an auditable formula citation. Accepts both kg and lb inputs directly.

## Known failure modes

- Missing both weight_kg and weight_lb parameters — returns error requiring at least one weight input
- Negative or zero weight value — likely returns a validation error
- Extremely high weight values may produce results outside clinically meaningful ranges but no guardrails are described
- Network or payment failure (402 x402 protocol) if USDC payment is not settled

## How this service works

Holliday–Segar 1957 daily maintenance water from weight: 100 mL/kg for the first 10 kg, 50 mL/kg for the next 10 kg, 20 mL/kg thereafter. Returns daily and hourly milliliters. Deterministic published arithmetic with citation; not a treatment order or IV prescription.

## Output

Returns the calculated daily maintenance fluid volume in milliliters (mL/day) and the hourly rate (mL/hr), derived deterministically from the Holliday-Segar 1957 formula: 100 mL/kg for the first 10 kg, 50 mL/kg for the next 10 kg, and 20 mL/kg for weight beyond 20 kg. The response includes a citation reference. Not a treatment order or prescription.

## 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": [],
     "properties": {
      "weight_kg": {
       "type": "number",
       "description": "Weight in kilograms. Provide weight_kg or weight_lb."
      },
      "weight_lb": {
       "type": "number",
       "description": "Weight in pounds. Converted as kg = lb * 0.45359237."
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "path": "/api/calc/maintenance_fluids",
  "count": 2,
  "items": [
   {
    "formula": "holliday_segar",
    "citation": {
     "id": "holliday-segar-1957",
     "doi": "10.1542/peds.19.5.823",
     "title": "The maintenance need for water in parenteral fluid therapy",
     "source": "Pediatrics. 1957;19(5):823-832",
     "authors": "Holliday MA, Segar WE"
    },
    "daily_ml": 1700,
    "hourly_ml": 70.8,
    "weight_kg": 30,
    "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.",
    "formula_expression": "daily_ml = 100*min(kg,10) + 50*max(0, min(kg,20)-10) + 20*max(0, kg-20); hourly_ml = daily_ml / 24"
   },
   {
    "formula": "holliday_segar",
    "citation": {
     "id": "holliday-segar-1957",
     "doi": "10.1542/peds.19.5.823",
     "title": "The maintenance need for water in parenteral fluid therapy",
     "source": "Pediatrics. 1957;19(5):823-832",
     "authors": "Holliday MA, Segar WE"
    },
    "daily_ml": 1700,
    "hourly_ml": 70.8,
    "weight_kg": 30,
    "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.",
    "formula_expression": "daily_ml = 100*min(kg,10) + 50*max(0, min(kg,20)-10) + 20*max(0, kg-20); hourly_ml = daily_ml / 24"
   }
  ]
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/holliday-segar-maintenance-fluid-calculator-c9faa02e/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)