# Roman Numeral Converter

> Roman Numeral Converter is a paid API for AI agents from number-words.x402tookit.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-30).

Converts integers (1–3999) to Roman numerals or parses Roman numeral strings back to integers, with strict/lenient reading and standard/additive writing styles.

## Facts

- Endpoint: GET https://number-words.x402tookit.com/roman-numeral?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-30
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/roman-numeral-converter-94f48f47
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_uwglvkTSxzPM1q9PUGV_F

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 roman-numeral-converter-94f48f47
```

Example prompt: Convert 1994 to a Roman numeral using standard style, and also tell me what number XLII represents — use strict reading mode.

## When to prefer this

Use this endpoint when you need bidirectional conversion between Arabic integers (1–3999) and Roman numerals, especially when you need control over parsing strictness (allowing archaic forms like IIII) or writing style (additive vs. subtractive). Prefer it over manual lookup tables or general-purpose LLM generation when correctness and structured output (with reasons and verdict) matter.

## Known failure modes

- Input integer out of range (below 1 or above 3999) — returns error or null
- Invalid Roman numeral characters in input — returns error or empty result in strict mode
- Strict mode rejection of non-standard forms like IIII or IC — result with verdict and reasons
- Missing required 'value' query parameter — returns validation error
- Ambiguous input that could be either digits or Roman letters — may be misinterpreted

## How this service works

Convert 1-3999 to Roman numerals or read Roman numerals as numbers, strict or lenient (IIII, IC), additive style option.

## Output

Returns the converted value (Roman numeral string or integer), the direction of conversion, the style and mode used, a human-readable summary, and optionally a list of reasons or warnings about the input form.

## 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"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "value"
     ],
     "properties": {
      "mode": {
       "enum": [
        "strict",
        "lenient"
       ],
       "type": "string",
       "description": "Reading Roman: strict (default; only standard forms) or lenient (also IIII, VIIII, IC, XM)"
      },
      "style": {
       "enum": [
        "standard",
        "additive"
       ],
       "type": "string",
       "description": "Writing Roman: standard (default, IV IX XL XC CD CM) or additive (IIII, VIIII, XXXX)"
      },
      "value": {
       "type": "string",
       "description": "Digits 1 to 3999 (becomes Roman) or Roman letters such as MCMXCIV (becomes a number)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "asOf": {
       "type": [
        "null",
        "string"
       ]
      },
      "input": {
       "type": [
        "null",
        "string"
       ]
      },
      "roman": {
       "type": [
        "null",
        "string"
       ]
      },
      "style": {
       "type": [
        "null",
        "string"
       ]
      },
      "number": {
       "type": [
        "null",
        "number"
       ]
      },
      "source": {
       "type": [
        "null",
        "string"
       ]
      },
      "reasons": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "summary": {
       "type": [
        "null",
        "string"
       ]
      },
      "verdict": {
       "type": [
        "null",
        "string"
       ]
      },
      "degraded": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "direction": {
       "type": [
        "null",
        "string"
       ]
      },
      "disclaimer": {
       "type": [
        "null",
        "string"
       ]
      },
      "notChecked": {
       "type": [
        "array",
        "nu
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/roman-numeral-converter-94f48f47/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from number-words.x402tookit.com](https://www.zero.xyz/host/number-words.x402tookit.com/llms.txt)