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textkit String Format Detector
x402
textkit String Format Detector is a paid API for AI agents from textkit.johnaio281.workers.dev, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-22).
Detects the string format of a given value, identifying whether it is a UUID, email, URL, IPv4 address, JWT, or IBAN
Price / call$0.005
Success—
StatusUnknown
How this service works
General-purpose text, Unicode and date utilities for AI agents: homoglyph folding and spoofed-domain detection, Unicode script detection, NFC/NFD normalization, grapheme counting, date description (weekday, ISO week, quarter, leap year), business-day counting, slugify, FNV-1a hashing, Shannon entropy, string format detection (uuid, email, url, ipv4, jwt, iban), byte-encoding detection and human-readable byte sizes. Pay per request in USDC on Base via x402 - no signup, no API key, no KYC.
Output
A JSON object with a 'valid' boolean indicating whether the input matches a recognized format, and a 'format' string naming the detected format (e.g. 'uuid', 'email', 'url', 'ipv4', 'jwt', 'iban').
Example use cases
Validate user-submitted identifier type
“I'm getting a string '2001:0db8:85a3::8a2e:0370:7334' from a form submission and I need to know if it's a valid IPv4 address, UUID, or some other recognized format before I process it.”
Detect JWT token in pipeline
“Can you check whether this string is a valid JWT: 'eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIn0.dozjgNryP4J3jVmNHl0w5N_XgL0n3I9PlFUP0THsR8U'?”
Identify IBAN in extracted text
“I pulled this string out of a document: 'GB29NWBK60161331926819' — can you tell me if that's an IBAN or some other format?”
Technical details
Endpoint
GEThttps://textkit.johnaio281.workers.dev/api/tk/detect-format?utm_source=zero.xyzWhen to prefer
Use this endpoint when you need lightweight, instant format classification of a string value without setting up authentication or API keys. Ideal for AI agents that need to route or validate user-submitted data on the fly. Particularly useful for detecting IBANs, JWTs, or UUIDs which are less commonly supported by generic validators. At $0.005 per call it's cost-effective for occasional validation tasks.
Side effects
- Missing 'value' query parameter returns an error
- Ambiguous strings that match no known format may return valid:false with no format
- Malformed input might return an unexpected format classification
- Payment failure via x402 if wallet has insufficient USDC on Base
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Output
Schema · Response
{
"type": "json",
"example": {
"valid": true,
"format": "uuid"
}
}Tags
x402
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