# FastX402 Lab Email Syntax Checker & Normalizer

> FastX402 Lab Email Syntax Checker & Normalizer is a paid API for AI agents from fastx402.tools, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-17).

Validates email address syntax and returns its normalized form (lowercase, Gmail dots and +tags stripped), local part, and domain — without contacting any mail server.

## Facts

- Endpoint: GET https://fastx402.tools/email-check?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-17
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/fastx402-lab-email-syntax-checker-normalizer-66b5131f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ThoDMdhJfkUwmP-jZSfZY

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 fastx402-lab-email-syntax-checker-normalizer-66b5131f
```

Example prompt: Can you check whether 'John.Smith+newsletter@GoogleMail.com' is a valid email and tell me its normalized form with the Gmail dots and plus-tags removed?

## When to prefer this

Choose this endpoint when you need fast, offline email syntax validation and normalization — particularly for deduplicating Gmail addresses that use dot tricks or plus-tag aliases. It is ideal for sign-up flows, contact list cleaning, and canonical identity matching. Do not use it when you need to verify actual deliverability (MX lookup or SMTP probe) — it explicitly does not contact any mail server.

## Known failure modes

- Missing 'email' query parameter returns an error response
- Malformed/unparseable email returns valid=false with possibly empty normalized field
- Extremely long or unusual inputs may return unexpected results
- Does not perform MX or SMTP checks — a syntactically valid email may not be deliverable

## How this service works

146 pay-per-call tools for AI agents, from $0.001 per request in USDC on Base or Solana with x402. No account, no API key.

## Output

A JSON object containing: the original email as submitted, a boolean 'valid' flag indicating syntax correctness, the 'local' part (before the @), the 'domain' (after the @, lowercased), and a 'normalized' form with lowercase applied and Gmail-specific aliases (dots in local part and +tags) removed.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "email"
     ],
     "properties": {
      "email": {
       "type": "string",
       "description": "Email address to check"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "email": {
       "type": "string"
      },
      "local": {
       "type": "string"
      },
      "valid": {
       "type": "boolean"
      },
      "domain": {
       "type": "string"
      },
      "normalized": {
       "type": "string"
      }
     }
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "email": "John.Smith+news@GoogleMail.com",
  "local": "John.Smith+news",
  "valid": true,
  "domain": "googlemail.com",
  "normalized": "johnsmith@gmail.com"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/fastx402-lab-email-syntax-checker-normalizer-66b5131f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from fastx402.tools](https://www.zero.xyz/host/fastx402.tools/llms.txt)