# ONE Engine Email Syntax Validator

> ONE Engine Email Syntax Validator is a paid API for AI agents from one-search.one-engine.workers.dev, paid per call via x402, $0.0009/call, status unknown (last checked 2026-10-02).

Validates whether an email address string is syntactically well-formed

## Facts

- Endpoint: POST https://one-search.one-engine.workers.dev/v1/email/syntax?utm_source=zero.xyz
- Price: $0.0009/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/one-engine-email-syntax-validator-508d8bc0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_2shtolIDQ8JPsleiDPtVz

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 one-engine-email-syntax-validator-508d8bc0 -d '<json body>'
```

Example prompt: Can you check if 'john.doe@example.com' is a syntactically valid email address before I try to use it?

## When to prefer this

Choose this endpoint when you need a fast, cheap, stateless syntax check on an email string with no side effects — ideal for agent pipelines that need to filter or validate user-supplied or scraped email addresses before passing them downstream. At $0.0009 USDC per call it is cost-effective for high-volume validation loops. Prefer a deliverability or MX-check service instead if you need to confirm the mailbox actually exists and can receive mail.

## Known failure modes

- Missing or empty email field in request body — likely returns an error or false
- Non-string input type for email field may cause parsing errors
- Payment failure via x402 if wallet lacks sufficient USDC on Base
- Network timeout if Cloudflare Workers instance is cold or overloaded
- Only checks syntax, not deliverability — a valid response does not mean the mailbox exists

## How this service works

Low-cost pay-per-call utility APIs for autonomous agents using x402 on Base.

## Output

A JSON object with a single boolean field 'valid' indicating whether the submitted email string conforms to standard email syntax rules. Returns {valid: true} for well-formed addresses and {valid: false} for malformed ones.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "email": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "valid": true
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/one-engine-email-syntax-validator-508d8bc0/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from one-search.one-engine.workers.dev](https://www.zero.xyz/host/one-search.one-engine.workers.dev/llms.txt)