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CUSIP Validator (2s.io)
x402
CUSIP Validator (2s.io) is a paid API for AI agents from 2s.io, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).
Validates a 9-character CUSIP securities identifier by verifying its structure and mod-10 weighted check digit, returning validity status and the reason for any failure.
Price / call$0.001
Success—
StatusUnknown
How this service works
Validate a CUSIP (9-character US/Canada securities identifier) with its mod-10 weighted check digit. Returns {valid, cusip, checkDigit, reason}. Catches transposed characters in security master / holdings data that a length check misses. Structure + checksum only.
Output
Returns a JSON object with: a boolean 'valid' field, the normalized 'cusip' string, the computed 'checkDigit' character, and a 'reason' string explaining any validation failure (e.g. wrong length, invalid characters, check digit mismatch).
Example use cases
Example prompt
“Can you check whether this CUSIP is valid: 037833100? I want to know if the check digit is correct and whether it's a well-formed identifier.”
Technical details
Endpoint
GEThttps://2s.io/api/validate/cusipWhen to prefer
Use this endpoint when you need to verify the structural integrity and check digit correctness of a CUSIP before inserting it into a security master, holdings database, or trade record. It catches transposed-character errors that a simple length or regex check would miss. Prefer this over manual computation when automating data ingestion pipelines for US/Canada securities.
Side effects
- Missing or empty 'cusip' query parameter returns an error
- CUSIP shorter or longer than 9 characters fails with a reason explaining the length issue
- Non-alphanumeric characters cause a structural validation failure
- Check digit mismatch is reported with valid=false and the expected vs actual digit
- Network or upstream errors return non-200 HTTP status
Input
{
"input": {
"type": "http",
"method": "GET",
"queryParams": {
"cusip": "037833100"
}
}
}Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object |
Output
{
"data": {
"ok": true,
"items": [
{
"cusip": "037833100",
"input": "037833100",
"valid": true,
"reason": null,
"checkDigit": "0"
}
],
"total": 1,
"source": {
"url": "https://2s.io",
"license": "No upstream license — computed by 2s.io",
"provider": "2s.io CUSIP validator"
}
},
"meta": {
"cost": {
"usd": 0.001,
"tier": 0
},
"caller": "x402",
"version": null,
"endpoint": "validate.cusip",
"settlement": {
"txHash": "0xb1340b145e9480ea9034785b6f2abc067fbd5dbec533073285b243be8113fe95",
"network": "eip155:8453",
"success": true
}
}
}Tags
x402
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