# PennyRail Email Validation

> PennyRail Email 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 and valid email address

## Facts

- Endpoint: POST https://pennyrail.vercel.app/api/p/nano/validation.email--email-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-email-validation-5946e628
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_GUGt1jBakDXOv3PE-Q7zb

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-validation-5946e628 -d '<json body>'
```

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

## When to prefer this

Use this endpoint when you need a quick, low-cost ($0.001 USDC) machine-readable email validation check — especially in agentic pipelines using the x402 micropayment protocol. Prefer this over regex-only checks when you want an API-backed validation decision, and over heavier SMTP-verification services when a lightweight format/syntax check suffices.

## Known failure modes

- Missing or empty input string returns validation error
- Malformed request body without required 'input' field returns 400-level error
- Payment failure via x402 protocol blocks the request
- Service timeout or Vercel cold-start latency may cause occasional delays
- Very long strings or non-string inputs may cause unexpected behavior

## How this service works

Machine-readable settlement service

## Output

Returns a JSON object indicating whether the provided string is a valid email address, likely including a boolean validity flag and possibly format or syntax details about the email.

## 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-validation-5946e628/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)