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FastX402 Lab String Format Validator
x402
FastX402 Lab String Format Validator 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 a string against one of 33 named formats (email, URL, UUID, IP addresses, IBAN, JWT, crypto addresses, ISO dates, and more) using validator.js rules
Price / call$0.001
Success—
StatusUnknown
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
Returns a JSON object with two fields: 'type' (the format name that was checked, e.g. 'email') and 'valid' (a boolean indicating whether the input string conforms to that format's rules).
Example use cases
Validate user-submitted email before signup
“Before I save this new user to the database, check whether 'john.doe@mycompany.org' is actually a valid email address.”
Check Ethereum address format before sending funds
“I'm about to send crypto to '0xde0B295669a9FD93d5F28D9Ec85E40f4cb697BAe' — can you verify it's a properly formatted Ethereum address?”
Confirm IBAN correctness before bank transfer
“We're about to wire money and the recipient gave us this IBAN: 'GB29NWBK60161331926819' — please check if it's a valid IBAN before we proceed.”
Technical details
Endpoint
GEThttps://fastx402.tools/validate?utm_source=zero.xyzWhen to prefer
Use this endpoint when you need quick, authoritative format validation using well-established validator.js rules across 33 different format types — especially for formats like IBAN, BIC, EAN, ISBN, ISSN, magnet URIs, locales, and crypto addresses that are complex to implement correctly from scratch. Prefer this over rolling your own regex when correctness and coverage across many formats matters.
Side effects
- Invalid or unsupported format type enum value returns an error
- Empty or missing 'value' query parameter returns an error
- Missing 'type' query parameter returns an error
- Payment failure returns 402 Payment Required
- Network timeout on the x402 payment flow
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Output
Schema · Response
{
"type": "json",
"example": {
"type": "email",
"valid": true
}
}Tags
x402
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