# Unit and Uncertainty Conversion

> Unit and Uncertainty Conversion is a paid API for AI agents from www.mahastrategies.com, paid per call via x402, $0.010006/call, status unknown (last checked 2026-10-15).

Converts a scalar measurement value with its standard uncertainty between length, mass, time, or temperature units using exact rational arithmetic, preserving declared uncertainty throughout.

## Facts

- Endpoint: POST https://www.mahastrategies.com/api/v1/compute/numerics/unit-uncertainty?utm_source=zero.xyz
- Price: $0.010006/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/unit-and-uncertainty-conversion-2411bfa0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_1XH25eCVF3nW_Ok2xzOeH

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 unit-and-uncertainty-conversion-2411bfa0 -d '<json body>'
```

Example prompt: Convert 2.75 kg to grams — the measurement has a standard uncertainty of 0.003 kg — treat it as an absolute quantity using exact arithmetic, and make sure the uncertainty is converted too.

## When to prefer this

Choose this endpoint when you need exact, reproducible unit conversion that explicitly preserves declared standard uncertainty using rational arithmetic — especially for scientific, engineering, or metrology workflows where uncertainty propagation is mandatory. Prefer this over generic calculators when the measurement has a known standard uncertainty that must be faithfully converted alongside the value, and when you need auditability via retained results. Not suitable for unit guessing, physical plausibility checks, or expanded uncertainty (coverage factor) calculations.

## Known failure modes

- Incompatible unit dimensions (e.g. converting length to mass) — API returns an error rather than guessing
- Value or uncertainty strings exceeding 21 characters — rejected with validation error
- Temperature absolute vs difference mismatch — absolute conversions apply offset, difference conversions do not; selecting wrong quantity type yields incorrect result
- Unsupported unit symbol not in the enum — request rejected
- Missing required fields (value, from, to) — returns schema validation error

## How this service works

Convert a measurement without losing declared uncertainty: one decimal value and standard uncertainty across supported length, mass, time or temperature units using exact rational scale/offset arithmetic. No unit guessing, physical validation or expanded uncertainty. New modular adapter: retained result recovery for 24 hours, minimal receipt metadata for 90 days. Existing live route unchanged.

## Output

Returns the converted numeric value and its propagated standard uncertainty in the target unit, computed using exact rational scale and offset arithmetic. No physical validation or expanded uncertainty is applied. Results are retained for 24 hours; receipt metadata is retained for 90 days.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "to": {
   "enum": [
    "m",
    "cm",
    "mm",
    "km",
    "kg",
    "g",
    "s",
    "min",
    "h",
    "K",
    "degC",
    "degF"
   ],
   "type": "string"
  },
  "from": {
   "enum": [
    "m",
    "cm",
    "mm",
    "km",
    "kg",
    "g",
    "s",
    "min",
    "h",
    "K",
    "degC",
    "degF"
   ],
   "type": "string"
  },
  "value": {
   "type": "string",
   "maxLength": 21
  },
  "quantity": {
   "enum": [
    "absolute",
    "difference"
   ],
   "type": "string"
  },
  "dataClass": {
   "enum": [
    "public",
    "synthetic"
   ],
   "type": "string"
  },
  "standardUncertainty": {
   "type": "string",
   "maxLength": 21
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/unit-and-uncertainty-conversion-2411bfa0/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from www.mahastrategies.com](https://www.zero.xyz/host/www.mahastrategies.com/llms.txt)