# 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 email address

## Facts

- Endpoint: POST https://pennyrail.vercel.app/api/f/validation.email
- 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-80caf37b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_rzPFeJiHBw7pu_KOeLDkl

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-80caf37b -d '<json body>'
```

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

## When to prefer this

Choose this endpoint when you need a lightweight, pay-per-call ($0.001 USDC) email format validation with no setup or API key required, particularly in agent workflows using x402 micropayment protocol. Best for single-string validation in automated pipelines where you want a machine-readable settlement service rather than a full identity verification or email deliverability check.

## Known failure modes

- Missing 'input' field in request body returns validation error
- Empty string input may return invalid result or error
- Malformed JSON body causes request rejection
- Network timeout on Vercel cold start
- Ambiguous result schema — 'result' field type is not strictly typed, so boolean vs string interpretation may vary

## How this service works

Machine-readable settlement service

## Output

Returns a JSON object with an 'operation' field (string identifying the validation operation performed) and a 'result' field (indicating whether the input string is a valid email address, likely a boolean or status indicator), plus any additional metadata fields.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "string",
   "description": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "operation",
  "result"
 ],
 "properties": {
  "result": {},
  "operation": {
   "type": "string"
  }
 },
 "additionalProperties": true
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/pennyrail-email-validation-80caf37b/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)