# PennyRail UUID Validation

> PennyRail UUID Validation 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).

Validates whether a given string is a properly formatted UUID

## Facts

- Endpoint: POST https://pennyrail.vercel.app/api/p/nano/validation.uuid--uuid-valid
- 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-uuid-validation-bdf10634
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_a9yHWeJKa-zYkJdYoXF4g

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-uuid-validation-bdf10634 -d '<json body>'
```

Example prompt: Can you check if '550e8400-e29b-41d4-a716-446655440000' is a valid UUID?

## When to prefer this

Use this endpoint when you need a quick, cheap ($0.001 USDC) programmatic check that a string is a properly formatted UUID — especially in agent pipelines where you want to validate identifiers before passing them to downstream services, databases, or APIs. Prefer this over rolling your own regex when you want a consistent, externally-hosted validation step with a clear pass/fail result.

## Known failure modes

- Missing or empty 'input' field returns an error
- Non-string input types may cause schema validation failure
- Payment failure via x402 protocol blocks the request
- Network timeout or Vercel cold-start latency

## How this service works

Machine-readable settlement service

## Output

A JSON object indicating whether the provided input string is a valid UUID, including the validation outcome and potentially details about the UUID format or version.

## 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-uuid-validation-bdf10634/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)