Roman Numeral Converter API Reference

Overview

Roman Numeral Converter works by converting numbers to Roman numerals using standard notation (I, V, X, L, C, D, M) or converting Roman numerals back to numbers. Supports numbers 1-3999 and validates Roman numeral syntax.

Endpoint

One host, one path per API. The block below shows this call in four languages; every one of them is the same HTTP request. Making requests covers the timeouts, retries and parameter rules that apply to all of them. The SDKs wrap the same call in a typed client.

GEThttps://api.apiverve.com/v1/romanconverter

curl "https://api.apiverve.com/v1/romanconverter?number=2024" \
  -H "x-api-key: your_api_key_here"

const res = await fetch('https://api.apiverve.com/v1/romanconverter?number=2024', {
  headers: { 'x-api-key': 'your_api_key_here' },
});

if (!res.ok) throw new Error(`${res.status} ${await res.text()}`);

const { data } = await res.json();
console.log(data);

import requests

res = requests.get(
    "https://api.apiverve.com/v1/romanconverter?number=2024",
    headers={"x-api-key": "your_api_key_here"},
    timeout=15,
)
res.raise_for_status()

print(res.json()["data"])

package main

import (
	"fmt"
	"io"
	"net/http"
)

func main() {
	req, _ := http.NewRequest("GET", "https://api.apiverve.com/v1/romanconverter?number=2024", nil)
	req.Header.Set("x-api-key", "your_api_key_here")

	res, err := http.DefaultClient.Do(req)
	if err != nil {
		panic(err)
	}
	defer res.Body.Close()

	out, _ := io.ReadAll(res.Body)
	fmt.Println(string(out))
}

Replace your_api_key_here with the key from your dashboard. When the inputs arrive as a list rather than one at a time, batch requests run up to 200 of them through this same API in a single call.

Authentication

Send your key in the x-api-key header. That is the only auth step — there is no token exchange and no per-endpoint scope to configure. Authentication covers creating, rotating and revoking keys.

401 is the only auth verdict

A 401 means the key is missing, invalid or expired. A 403 means the key is valid but not permitted here — blocked by a key restriction or an IP allow-list. Running out of credits is a 429.

Parameters

Sent in the query string. Premium parameters are accepted on every plan but only take effect on plans that include them.

Parameter	Type	Description
`number`Required	integer	The number to convert to Roman numerals range 1–3999

Response

Every API returns the same three top-level keys, so one response handler covers your whole integration: status, error and data. Only data changes shape. Response format covers the envelope, the other output formats and how premium fields are withheld.

Sample response

{
  "status": "ok",
  "error": null,
  "data": {
    "number": 2024,
    "roman": "MMXXIV",
    "breakdown": {
      "M": 2,
      "X": 2,
      "IV": 1
    }
  }
}

Response fields

Paths are relative to data. Premium fields are absent rather than zeroed on plans that do not include them, so check for presence instead of comparing to 0.

Field	Type	Example	Description
`number`	number	`2024`	The converted number from Roman numeral input
`roman`	string	`"MMXXIV"`	The original Roman numeral provided for conversion
`breakdown`	object	`{...}`	Object containing Roman numeral components and their counts
`M`Premium	number	`2`	Count of M (1000) symbols in breakdown
`X`Premium	number	`2`	Count of X (10) symbols in breakdown
`IV`Premium	number	`1`	Count of IV (4) subtractive pairs in breakdown

Errors

Read the HTTP status first, then error for the specific reason. The body names the parameter that has to change. Error handling covers the full status list and which of them are worth retrying.

Status	Meaning	What to do
`400`	Input was rejected	Read `error`; it names the parameter.
`401`	Key missing or invalid	Check the header name and the key value.
`403`	Key valid, but not permitted	A key restriction or IP allow-list; see key scoping.
`429`	Rate limited, or out of credits	Read `error` to tell them apart; see rate limits.

Use cases

Document Formatting: Convert numbers to Roman numerals for page numbering, chapter headings, or formal document sections
Historical Data: Convert Roman numeral dates and numbers from historical documents into modern numeric format
Educational Tools: Teach Roman numeral systems by providing conversions and detailed breakdowns of numeral components
Content Generation: Generate Roman numerals for lists, outlines, or hierarchical structures in generated content

Other ways to use Roman Numeral Converter

Set up Roman Numeral Converter on APIVerve, or reach the same source a different way. Your APIVerve account and credits work on all of them — one key, one balance.

Give it to an AI agentConnect over MCP and your agent calls it as a native tool — Claude, Cursor, ChatGPT.VerveKit →Reference →

Use it in Google Sheets or ExcelA =VERVE() formula fills a column — no script, no export, recalculates in place.VerveSheets →Reference →

Ground an agent on itA cited, machine-checkable fact your model can't produce on its own.VerveContext →Reference →

Roman Numeral Converter