Roman Numeral Converter is a bidirectional tool for converting between Arabic numbers (1-3999) and Roman numerals. It provides detailed breakdowns of the conversion process.
Try it — live request, no key required
No key required to try it. Get a key to use it in your app.
{
"status": "ok",
"error": null,
"data": {
// Roman Numeral Converter response payload
}
}
About the Roman Numeral Converter API
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.
What people use it for
- 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- Convert Roman numeral dates and numbers from historical documents into modern numeric format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
Ways to call it
One endpoint, many ways in — REST with JSON, XML, YAML and CSV, plus GraphQL and an MCP interface for AI agents.
- JSON
- Default REST response
- XML
- Markup format
- YAML
- Human-readable
- CSV
- Tabular export
- GraphQL
- Query language
- MCP
- For AI agents
Other ways to use Roman Numeral Converter
Same data, same APIVerve account, same credit balance — one key works on all of them.
What does the Roman Numeral Converter API do?
How do I authenticate Roman Numeral Converter API requests?
How much does the Roman Numeral Converter API cost?
How fast is the Roman Numeral Converter API?
What response formats does the Roman Numeral Converter API support?
What HTTP method does the Roman Numeral Converter API use?
Request parameters — GET /v1/romanconverter
Sent in the query string. Premium parameters are accepted on every plan but only take effect on plans that include them. Anything not listed here is dropped rather than passed through.
Required
| Parameter | Type | Example | Description |
|---|---|---|---|
numberRequired | integer | 2024 | The number to convert to Roman numerals range 1-3999 |
curl "https://api.apiverve.com/v1/romanconverter?number=2024" \
-H "x-api-key: YOUR_API_KEY"Authentication
Send your key in the x-api-key header. That is the only auth step — no token exchange, and no per-endpoint scope to configure.
| Header | When | Value |
|---|---|---|
x-api-keyRequired | Every request | Your API key. Header names are case-insensitive, so X-API-Key is the same header. |
AuthorizationAlternate | Instead of the above | Bearer <key> — for clients that only expose bearer auth. Resolves to the same account and the same billing. |
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.
Response — GET /v1/romanconverter
Every APIVerve endpoint returns the same three top-level keys, so one response handler covers your whole integration: status, error and data. Only data changes shape.
{
"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 original number provided for conversion |
roman | string | "MMXXIV" | The Roman numeral representation of the number |
breakdown | object | {...} | Object containing Roman numeral components and their counts |
MPremium | number | 2 | Count of M (1000) symbols in breakdown |
XPremium | number | 2 | Count of X (10) symbols in breakdown |
IVPremium | number | 1 | Count of IV (4) subtractive pairs in breakdown |
Response headers
Every response carries your balance, so your own code always knows where it stands without polling anything. All four are exposed to browsers through CORS.
| Header | What it carries |
|---|---|
x-api-remaining-credits | Credits left in the current cycle |
x-api-credits-used | Credits spent in the current cycle |
x-api-max-credits | The allowance for the cycle |
x-api-version | Version of the endpoint that answered |
Errors
Read the HTTP status first, then error for the specific reason. The body names the parameter that has to change.
| Status | Meaning | What to do |
|---|---|---|
400 | Input was rejected | Read error; it names the parameter that has to change. |
401 | Key missing or invalid | Check the header name and the key value. |
403 | Key valid, but not permitted here | A key restriction or an IP allow-list — never a bad key. |
429 | Rate limited, or out of credits | Read error to tell them apart, then back off or top up. |
What a call costs — 2 credits per call
Credits are shared across every APIVerve API — one balance, one key, one bill. Failed requests never count against it, so a rejected input costs nothing.
| Plan | Per month | Credits | Roman Numeral Converter calls | Per 1,000 calls |
|---|---|---|---|---|
| Free | Free | 200 | 100 | Free |
| Starter | $29.99 | 200,000 | 100,000 | $0.30 |
| Pro | $99.99 | 1,000,000 | 500,000 | $0.20 |
| Mega | $299.99 | 4,000,000 | 2,000,000 | $0.15 |
Calls are what the credits buy at this API's rate — spend them here, on any of the other APIs, or across both. Nothing is reserved per endpoint.
Call it from cURL — GET /v1/romanconverter
No SDK to install — this is a plain HTTPS call to /v1/romanconverter with your key in the x-api-key header. Swap in a real key and it runs as-is.
curl "https://api.apiverve.com/v1/romanconverter" \
-H "x-api-key: YOUR_API_KEY"Resources
Also published for
Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.
Call it from Node.js — GET /v1/romanconverter
Install the Node.js SDK, then call the Roman Numeral Converter API with your key. The client wraps the same HTTPS request, so anything it returns is what the endpoint returns.
npm install @apiverve/romanconverterconst res = await fetch("https://api.apiverve.com/v1/romanconverter", {
headers: { "x-api-key": "YOUR_API_KEY" },
});
const { data } = await res.json();
console.log(data);Resources
Also published for
Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.
Call it from Python — GET /v1/romanconverter
No SDK to install — this is a plain HTTPS call to /v1/romanconverter with your key in the x-api-key header. Swap in a real key and it runs as-is.
import requests
res = requests.get(
"https://api.apiverve.com/v1/romanconverter",
headers={"x-api-key": "YOUR_API_KEY"},
)
print(res.json()["data"])Resources
Also published for
Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.
Call it from C# / .NET — GET /v1/romanconverter
Install the C# / .NET SDK, then call the Roman Numeral Converter API with your key. The client wraps the same HTTPS request, so anything it returns is what the endpoint returns.
dotnet add package APIVerve.API.RomanNumeralConverterusing var client = new HttpClient();
client.DefaultRequestHeaders.Add("x-api-key", "YOUR_API_KEY");
var json = await client.GetStringAsync("https://api.apiverve.com/v1/romanconverter");
Console.WriteLine(json);Resources
Also published for
Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.
Call it from Go — GET /v1/romanconverter
No SDK to install — this is a plain HTTPS call to /v1/romanconverter with your key in the x-api-key header. Swap in a real key and it runs as-is.
req, _ := http.NewRequest("GET", "https://api.apiverve.com/v1/romanconverter", nil)
req.Header.Set("x-api-key", "YOUR_API_KEY")
res, _ := http.DefaultClient.Do(req)
defer res.Body.Close()
body, _ := io.ReadAll(res.Body)
fmt.Println(string(body))Resources
Also published for
Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.
Call it from PHP — GET /v1/romanconverter
No SDK to install — this is a plain HTTPS call to /v1/romanconverter with your key in the x-api-key header. Swap in a real key and it runs as-is.
$ch = curl_init("https://api.apiverve.com/v1/romanconverter");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, ["x-api-key: YOUR_API_KEY"]);
$response = curl_exec($ch);
echo $response;Resources
Also published for
Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.
Call it from Ruby — GET /v1/romanconverter
No SDK to install — this is a plain HTTPS call to /v1/romanconverter with your key in the x-api-key header. Swap in a real key and it runs as-is.
require "net/http"
uri = URI("https://api.apiverve.com/v1/romanconverter")
req = Net::HTTP::Get.new(uri)
req["x-api-key"] = "YOUR_API_KEY"
res = Net::HTTP.start(uri.hostname, uri.port, use_ssl: true) { |h| h.request(req) }
puts res.bodyResources
Also published for
Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.
Zero-code embed — one snippet, no backend
Drop an interactive Roman Numeral Converter form onto any page. The widget calls the API for you, so no key ever appears in your markup and there is nothing to deploy.
Changelog — Roman Numeral Converter API
Every change to this endpoint, newest first. Breaking changes ship as a new version and the previous one keeps serving — response fields are added, never removed or retyped in place, so an integration written against v1 keeps working.
Entries are picked up from dated catalog snapshots, so the first one appears after the next snapshot that moves something. A period where nothing changed produces no entry — silence is a valid changelog for the Roman Numeral Converter API.
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