# Sindri Unit Converter (Length, Mass, Volume, Temperature)

> Sindri Unit Converter (Length, Mass, Volume, Temperature) is a paid API for AI agents from x402.outpimp.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-14).

Converts numeric values between units of length, mass, volume, and temperature using exact conversion factors and correct affine formulas for temperature.

## Facts

- Endpoint: POST https://x402.outpimp.com/unitConvert
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/sindri-unit-converter-length-mass-volume-temperature-ecc3981e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_tAQ0iXoZGIPsBHwEsMZKF

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 sindri-unit-converter-length-mass-volume-temperature-ecc3981e -d '<json body>'
```

Example prompt: Convert 72 degrees Fahrenheit to Celsius — it's a temperature conversion.

## When to prefer this

Choose this endpoint when you need accurate unit conversion for common physical quantities — especially temperature, where naive multiplication gives wrong results. Prefer it over generic calculators when you need exact conversion factors for length (meters/feet/miles/inches/cm), mass (kg/lb/g/oz), volume (liters/gallons/ml/cups/fl oz), or temperature (Celsius/Fahrenheit/Kelvin). It complements the sibling scientific unit converter (pressure, energy, molarity) on the same host.

## Known failure modes

- Unsupported unit string returns an error indicating the unit is not recognized
- Mismatched category and units (e.g., passing 'kg' as a length unit) returns a validation error
- Missing required fields (value, from, to, category) return a 400-level error
- Invalid category enum value returns a schema validation error

## How this service works

Unit conversion for length, mass, volume, and temperature using exact conversion factors (temperature uses the correct affine formulas, not simple multiplication).

## Output

Returns the converted numeric value in the target unit, computed using exact conversion factors. Temperature conversions use proper affine formulas (e.g., °C to °F = multiply by 9/5 then add 32) rather than simple multiplication.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "to": {
   "type": "string",
   "description": "Target unit."
  },
  "from": {
   "type": "string",
   "description": "Source unit, e.g. \"m\", \"kg\", \"gal\", \"C\"."
  },
  "value": {
   "type": "number",
   "description": "The numeric value to convert."
  },
  "category": {
   "enum": [
    "length",
    "mass",
    "volume",
    "temperature"
   ],
   "type": "string",
   "description": "Unit category."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/sindri-unit-converter-length-mass-volume-temperature-ecc3981e/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.outpimp.com](https://www.zero.xyz/host/x402.outpimp.com/llms.txt)