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x402 Format Checker – Email Validation
x402
x402 Format Checker – Email Validation is a paid API for AI agents from validate.crewofthecaptain.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-12).
Validates the format and syntax of an email address and returns a validity flag, reason, and normalized form, paid per-call via x402 in USDC.
Price / call$0.001
Success—
StatusUnknown
How this service works
Format and checksum validation for IBAN, EU VAT, Polish NIP/REGON/PESEL and email, pay-per-call via x402. Only $0.001 (0.1 cent) per check, paid via x402 in USDC on Base.
Output
A JSON object with: 'type' (always 'email'), 'valid' (boolean indicating whether the address passes format and syntax checks), 'reason' (string explaining the outcome, e.g. 'ok' or a specific error), and 'normalized' (the canonicalized form of the email address).
Example use cases
User registration email check
“Before I save this new account, can you verify that 'john.doe@gmail.com' is a properly formatted email address?”
Bulk import data quality gate
“I'm about to import a CSV of contacts — can you validate whether 'info@my-company.org' is a valid email so I can flag bad rows?”
Form submission pre-flight validation
“A user just submitted 'jane@@example..com' as their email in a checkout form — is that actually a valid email address?”
Technical details
Endpoint
POSThttps://validate.crewofthecaptain.com/api/validate/email?utm_source=zero.xyzWhen to prefer
Choose this endpoint when you need a lightweight, pay-per-use email format and syntax validator with no subscription required — ideal for low-volume checks, agent workflows, or pipelines where you want to pay only for what you use via crypto microtransaction. Prefer this over heavyweight email deliverability services when you only need format/syntax validation, not MX-record or SMTP-level reachability checks.
Side effects
- Missing or empty 'value' field returns a validation error
- Input exceeding 512 characters may be rejected
- Malformed JSON body returns a 400-level error
- x402 payment failure or insufficient USDC balance returns a 402 Payment Required response
- Non-email strings (e.g. IBANs, phone numbers) will return valid:false with an appropriate reason
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| value | string |
Output
Schema · Response
{
"type": "json",
"example": {
"type": "email",
"valid": true,
"reason": "ok",
"normalized": "…"
}
}Tags
x402
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