# PennyRail Email Shape Validator

> PennyRail Email Shape Validator is a paid API for AI agents from pennyrail.vercel.app, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).

Validates whether a given string conforms to a well-formed email address shape/format

## Facts

- Endpoint: POST https://pennyrail.vercel.app/api/p/nano/validation.email--validate-email-shape
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/pennyrail-email-shape-validator-7360b77e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_I0B3EYXwjcc9I32FWGe9L

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-email-shape-validator-7360b77e -d '<json body>'
```

Example prompt: Can you check whether 'john.doe@example.com' is a properly shaped email address before I save it to the database?

## When to prefer this

Choose this endpoint when you need a lightweight, pay-per-call email shape/syntax check via a micropayment-gated API, especially in agent workflows already using x402/USDC payment rails, and where spinning up a full email verification library is overkill. Prefer alternatives that do live deliverability checks (DNS/MX lookup) if you need more than syntactic shape validation.

## Known failure modes

- Missing or empty input field returns validation error
- Non-string input type may cause schema rejection
- Network or payment settlement failure returns 402 or 5xx
- Ambiguous edge-case addresses (e.g. internationalized domains) may produce unexpected results

## How this service works

Machine-readable settlement service

## Output

Returns a JSON object indicating whether the input string conforms to the expected shape/format of an email address, likely including a boolean validity flag and possibly error details or shape diagnostics.

## 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-email-shape-validator-7360b77e/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)