# agent402.tools ROT13 / Caesar Cipher

> agent402.tools ROT13 / Caesar Cipher is a paid API for AI agents from agent402.tools, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).

Applies a Caesar cipher (default ROT13, shift 13) to a string, with configurable shift values from 1 to 25.

## Facts

- Endpoint: POST https://agent402.tools/api/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/agent402-tools-rot13-caesar-cipher-cbf85d99
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_X2-7Kt5a7lx2OnSMwpfgJ

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 agent402-tools-rot13-caesar-cipher-cbf85d99 -d '<json body>'
```

Example prompt: ROT13-encode this text for me: 'The quick brown fox jumps over the lazy dog' — use the default shift of 13.

## When to prefer this

Use this endpoint when you need a quick, reliable Caesar cipher or ROT13 transformation of a string without setting up any local encoding logic. Ideal for obfuscating spoilers, simple encoding tasks, or decoding ROT13 messages. Since ROT13 is self-inverse, running the same text through twice (shift=13) restores the original.

## Known failure modes

- Invalid shift value outside 1-25 range may return an error or be rejected
- Empty text input may return an empty string or error
- Non-string text input may cause a validation error
- Missing required text field returns a bad request error

## How this service works

Caesar-cipher a string. Default shift 13 (ROT13, self-inverse). Set shift for any rotation 1-25.

## Output

Returns the Caesar-ciphered version of the input string, with all alphabetic characters rotated by the specified shift (default 13). Non-alphabetic characters are typically passed through unchanged.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "text": {
   "type": "string"
  },
  "shift": {
   "type": "number",
   "description": "1-25 (default 13)"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "result": "Uryyb"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agent402-tools-rot13-caesar-cipher-cbf85d99/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agent402.tools](https://www.zero.xyz/host/agent402.tools/llms.txt)