Identify an identifier's kind: UUID version, ULID, KSUID, snowflake, Stripe/GitHub/AWS prefix, EVM address, email, E.164

$0.005 USDC per call · Business, finance and compliance · POST /api/v1/id-kind · Id id-kind

Classifies up to 100 identifier strings by format and, where it can be read, decodes the embedded timestamp, for an agent that must not pass an id of the wrong kind to a payment, ledger or API call. Recognises UUID (RFC 9562 version and variant, nil and max), ULID, KSUID, Discord and Twitter snowflakes, EIP-55 EVM addresses (checksum verified), email (WHATWG syntax and RFC 5321 length limits), E.164 shape, Stripe object prefixes (cus_, pi_, ch_ ...), GitHub token prefixes and AWS IAM unique-id prefixes, each match citing its source. Several valid readings (an all-digit 19-digit id is both a Discord and a Twitter snowflake) return unknown with every reading; with `expect` the answer is pass or fail for that kind. A prefix match is a candidate, not proof of the vendor; nothing is looked up in any registry. Credential-shaped values (GitHub tokens, AWS access keys) are never echoed.

What you get

Sending a customer id where a payment-intent id belongs, or a checksum-less address, is a real-money error. 100 ids per $0.005, each with the source of its rule.

Call it

Send the JSON body below to https://agents.writerslogic.com/api/v1/id-kind. An unpaid request answers 402 with the price and how to pay; a request that fails with a 5xx status is not charged.

curl -i -X POST https://agents.writerslogic.com/api/v1/id-kind \
  -H 'content-type: application/json' \
  -d '{"items":[{"value":"018f3b1a-7c2e-7a1b-9d3e-0123456789ab"},{"value":"cus_NffrFeUfNV2Hib","expect":"stripe-object-id"},{"value":"175928847299117063"},{"value":"pi_3MtwBwLkdIwHu7ix28a3tqPa","expect":"uuid"}]}'

Input

Field	Type	Required	Description
`items`	array<object>; max 100 items	yes

Example request body

{
  "items": [
    {
      "value": "018f3b1a-7c2e-7a1b-9d3e-0123456789ab"
    },
    {
      "value": "cus_NffrFeUfNV2Hib",
      "expect": "stripe-object-id"
    },
    {
      "value": "175928847299117063"
    },
    {
      "value": "pi_3MtwBwLkdIwHu7ix28a3tqPa",
      "expect": "uuid"
    }
  ]
}

Result

The response is { "data": ..., "_provenance": ... }. data carries these fields; _provenance is a signed W3C Verifiable Credential with a C2PA-style manifest, checked free at POST /api/v1/verify-provenance.

Field	Type	Required	Description
`status`	string; one of "pass", "fail", "unknown", "unsupported"	no	pass: every rule held. fail: a rule was violated (see witnesses). unknown: the input lacks the evidence to decide. unsupported: outside what this engine covers. Missing evidence is never a pass.
`items`	array<object>	no
`witnesses`	array<object>	no
`versions`	object	no	Every semantic dependency of this answer (engine, tables and their as-of dates, tokenizer, calendar, rounding profile).
`limits`	array<string>	no
`deterministic`	boolean	no	Always true: pure code, no model.

Pay and connect

Available through: x402 (USDC on Base), MCP. MCP clients reach it through the money-math-kit package.

Machine-readable

This agent as JSON (schemas, example, OpenAPI operation)
Free signed sample response
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