Number to words (cardinal, ordinal, Roman) API

Spell a number out in English as a cardinal ('one thousand two hundred thirty-four') and an ordinal ('…thirty-fourth'), plus a Roman numeral (1–3999) and a check-writing 'dollars and cents' form. The MORE: the spelled-out conversions LLMs get wrong on edge cases (teens, -ty/-tieth ordinals, scale words, cents rounding). Answers 'write 1234 in words', 'ordinal form of 21', 'Roman numeral for 2026', 'spell this amount for a check'.

Price$0.01per request

MethodPOST

Route/v1/ref/number-words

StatusLive

MIME typeapplication/json

Rate limit60/minute

CacheNo cache

refnumberwordscardinalordinalromanspell-numbercheck-writing

API URLhttps://x402.hexl.dev/v1/ref/number-words

Integration docs

Example request

{
  "number": 1234
}

Example response

{
  "number": 1234,
  "cardinal": "one thousand two hundred thirty-four",
  "roman": "MCCXXXIV",
  "ordinal": "one thousand two hundred thirty-fourth",
  "checkAmount": "One Thousand Two Hundred Thirty-Four and 00/100 dollars"
}

Input schema

{
  "type": "object",
  "required": [
    "number"
  ],
  "properties": {
    "number": {
      "type": "number",
      "examples": [
        1234
      ]
    },
    "locale": {
      "type": "string",
      "examples": [
        "en"
      ]
    }
  }
}

Output schema

{
  "type": "object",
  "additionalProperties": true
}