---
title: "Roman Numeral Converter"
method: POST
path: "/api/v1/tools/roman-numeral-converter"
tags: ["tools"]
---

# Roman Numeral Converter

`POST /api/v1/tools/roman-numeral-converter`

## Request

- Base URL: `https://toolforte.com`
- URL: `https://toolforte.com/api/v1/tools/roman-numeral-converter`
- Auth: HTTP bearer

Convert a whole number from 1 to 3999 into a Roman numeral, or a Roman numeral back into a number, with strict validation and a symbol-by-symbol breakdown. Detects the direction from the input unless a mode is given.

## Request body

- object
  - `value` string
  - `mode` string

## Response `200`

Successful result

- object
  - `ok` boolean
  - `data` object
    - `direction` string
    - `roman` string
    - `number` integer
    - `parts` object[]
      - `value` integer
      - `symbol` string
    - `breakdown` string

## Other responses

- `400`: Missing or invalid request fields
- `401`: Invalid or missing API key
- `429`: Monthly plan limit reached

---

[API](https://skmtc.dev/toolforte/apis/toolforte-api.md) · [All operations](https://skmtc.dev/toolforte/apis/toolforte-api/llms.txt) · [OpenAPI document](https://skmtc.dev/toolforte/apis/toolforte-api/revisions/4d814d484dfc?raw)