# fx402 Physical Unit Converter

> fx402 Physical Unit Converter is a paid API for AI agents from fx402.alogos.xyz, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-15).

Converts a numeric value from one physical unit to another across categories like length, mass, temperature, volume, area, speed, time, and digital storage — pay-per-call via x402/USDC.

## Facts

- Endpoint: GET https://fx402.alogos.xyz/v1/units
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/fx402-physical-unit-converter-1d607948
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_2JeMgOaQWfXlLG6cIf87r

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 fx402-physical-unit-converter-1d607948
```

Example prompt: Convert 26.2 miles to kilometers for me — using the fx402 unit converter.

## When to prefer this

Choose this endpoint when an AI agent needs a reliable, serverless, pay-per-call physical unit conversion without requiring an API key or subscription — especially in automated workflows where pre-paid USDC micropayments via x402 on Base are acceptable. Prefer this over currency conversion endpoints when converting physical quantities like length, weight, temperature, or digital storage.

## Known failure modes

- Incompatible unit categories (e.g. converting 'kg' to 'km') — returns an error indicating unit mismatch
- Unknown or misspelled unit symbol — returns an error listing unrecognized symbol
- Missing required parameter (from, to, or value) — returns a 400-level validation error
- Payment failure via x402/MPP — returns 402 Payment Required before conversion is performed

## How this service works

Pay-per-call currency and unit conversion utility for AI agents: currency exchange at ECB daily reference rates, FX rate tables, and physical unit conversion (length, mass, temperature, volume, area, speed, time, digital). No API key, no subscription — agents pay per request via x402 (Base/USDC) or MPP (Tempo/pathUSD).

## Output

The agent receives the converted numeric value expressed in the target unit, computed precisely from the given source value and unit symbols.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "to",
  "from",
  "value"
 ],
 "properties": {
  "to": {
   "type": "string",
   "description": "Target unit symbol in the same category, e.g. 'mi'."
  },
  "from": {
   "type": "string",
   "description": "Source unit symbol, e.g. 'km', 'kg', 'C', 'L', 'mph', 'GiB'."
  },
  "value": {
   "type": "number",
   "description": "Numeric value to convert."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "to": {
   "type": "string"
  },
  "from": {
   "type": "string"
  },
  "value": {
   "type": "number"
  },
  "result": {
   "type": "number"
  },
  "category": {
   "type": "string"
  },
  "converted": {
   "type": "number"
  }
 },
 "additionalProperties": true
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/fx402-physical-unit-converter-1d607948/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from fx402.alogos.xyz](https://www.zero.xyz/host/fx402.alogos.xyz/llms.txt)