# PennyRail ROT13 Text Encoder

> PennyRail ROT13 Text Encoder 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).

Applies ROT13 Caesar cipher transformation to an input string, shifting each letter by 13 positions

## Facts

- Endpoint: POST https://pennyrail.vercel.app/api/p/nano/text.rot13--rot13
- 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-rot13-text-encoder-2e2c478b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_t1Gog2Ug3VFCbVJslk7Cj

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-rot13-text-encoder-2e2c478b -d '<json body>'
```

Example prompt: Can you run ROT13 encoding on this text for me: 'Hello World, this is a secret message'?

## When to prefer this

Choose this endpoint when you need a quick, pay-per-use ROT13 transformation without hosting your own cipher logic, especially in x402-enabled micropayment workflows where cost accountability per operation matters. It is idempotent and self-inverse, making it suitable for both encoding and decoding in a single endpoint.

## Known failure modes

- Missing required 'input' field returns a validation error
- Non-string input type may cause a 400 or processing error
- Payment failure (x402) if USDC allowance is insufficient — returns 402 Payment Required
- Empty string input may return an empty or trivially encoded result
- Network timeout on the Vercel serverless function under cold-start conditions

## How this service works

Machine-readable settlement service

## Output

Returns a JSON object containing the ROT13-transformed version of the input string, where every alphabetical character is shifted 13 positions in the alphabet and non-alphabetical characters are left unchanged.

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

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

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/pennyrail-rot13-text-encoder-2e2c478b/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)