# Touchstone Unit Converter

> Touchstone Unit Converter is a paid API for AI agents from touchstone.locomot.io, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).

Converts a numeric quantity from one unit of measurement to another within the same dimension (e.g. miles to kilometers, kg to pounds, °C to °F).

## Facts

- Endpoint: GET https://touchstone.locomot.io/unit
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/touchstone-unit-converter-bd927d2d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_q3gulUILlNpbvMiDxxLMF

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 touchstone-unit-converter-bd927d2d
```

Example prompt: Convert 26.2 miles to kilometers for me — I need the exact result and want to know the conversion factor used.

## When to prefer this

Choose this endpoint when you need a reliable, pay-per-call unit conversion with structured output including conversion factor and dimension metadata. Useful when you want machine-readable results (exact flag, dimension) rather than just a plain text answer, or when embedding unit conversion into an automated workflow.

## Known failure modes

- Incompatible units (different dimensions) — e.g. converting kg to meters returns an error
- Unknown unit name or alias not recognized by the service
- Missing required query parameters (value, from, or to) returns a 400-style error
- Payment not attached or insufficient — returns HTTP 402 requiring x402 payment of $0.001 USDC

## How this service works

Deterministic unit conversion reproducing NIST SP 811 exact factors (length, mass, volume, energy, power, pressure, force, area, speed, data, angle, frequency + affine temperature). Every answer signed. Free sample, no payment required: GET /play/unit

## Output

Returns the converted numeric result, the conversion factor applied, the physical dimension (e.g. length, mass, temperature), whether the conversion is exact, the source and target unit names, the input value, and the operation description.

## 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"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "value",
      "from",
      "to"
     ],
     "properties": {
      "to": {
       "type": "string",
       "description": "target unit (same dimension)"
      },
      "from": {
       "type": "string",
       "description": "source unit (name or alias, e.g. mile, kg, °C)"
      },
      "value": {
       "type": "number",
       "description": "quantity to convert"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "properties": {
    "op": {
     "type": "string"
    },
    "to": {
     "type": "string"
    },
    "from": {
     "type": "string"
    },
    "exact": {
     "type": "boolean"
    },
    "value": {
     "type": "number"
    },
    "result": {
     "type": "number"
    },
    "source": {
     "type": "string"
    },
    "dimension": {
     "type": "string"
    },
    "conversion_factor": {
     "type": "number"
    },
    "conversion_factor_ratio": {
     "type": "string"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/touchstone-unit-converter-bd927d2d/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from touchstone.locomot.io](https://www.zero.xyz/host/touchstone.locomot.io/llms.txt)