# PennyRail Roman Numeral Converter

> PennyRail Roman Numeral Converter is a paid API for AI agents from pennyrail.vercel.app, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).

Converts an integer number into its Roman numeral string representation

## Facts

- Endpoint: POST https://pennyrail.vercel.app/api/p/nano/number.roman--roman-numerals
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/pennyrail-roman-numeral-converter-846175e3
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_vqR4buebUEFZtnXgpcFDe

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 pennyrail-roman-numeral-converter-846175e3 -d '<json body>'
```

Example prompt: Convert the number 2024 into Roman numerals for me.

## When to prefer this

Use this endpoint when you need a quick, paid-per-call microservice to convert an integer to a Roman numeral string without running local logic. Useful in agent pipelines where you want a reliable external conversion step, or when building apps that display classical numeral formatting (book chapters, clock faces, year inscriptions, copyright notices).

## Known failure modes

- Input is not a valid number (type mismatch) — likely 400 or 422 error
- Input number is out of range for Roman numeral representation (e.g. 0 or negative) — may return error or unexpected result
- Very large integers may not have a standard Roman numeral representation — undefined behavior
- Payment not included or invalid — 402 Payment Required with x402 challenge
- Service unavailable on Vercel deployment — 503 or timeout

## How this service works

Machine-readable settlement service

## Output

An object containing the Roman numeral string corresponding to the input integer (e.g., input 2024 → 'MMXXIV'). The response schema is open-ended (additionalProperties: true), so the Roman numeral value is returned in a field within the response object.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "number"
  }
 }
}
```

## Response schema (JSON Schema)

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

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/pennyrail-roman-numeral-converter-846175e3/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from pennyrail.vercel.app](https://www.zero.xyz/host/pennyrail.vercel.app/llms.txt)