# PennyRail Email Address Validation

> PennyRail Email Address 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 email address is properly formatted and deliverable

## Facts

- Endpoint: POST https://pennyrail.vercel.app/api/p/nano/validation.email--email-address-validation
- 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-email-address-validation-5b3af5d5
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap__GpsJ5n-IunMRmYsYd2-x

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-address-validation-5b3af5d5 -d '<json body>'
```

Example prompt: Can you check whether 'john.doe@example.com' is a valid email address before I add it to my contact list?

## When to prefer this

Choose this endpoint when you need a quick, low-cost ($0.001 USDC) pay-per-call email validation without a subscription, especially in agent workflows using the x402 micropayment protocol. Ideal for spot-checking individual email addresses in real time rather than batch processing.

## Known failure modes

- Missing or empty input string returns an error
- Malformed request body (missing 'input' field) causes a 400-level error
- Payment not fulfilled results in 402 response before validation occurs
- Service timeout if upstream validation provider is slow

## How this service works

Machine-readable settlement service

## Output

Returns a JSON object indicating whether the provided email address passes validation checks, typically including format correctness and potentially deliverability signals.

## 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-address-validation-5b3af5d5/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)