ISIN, CUSIP and SEDOL Validator
ISIN validator plus CUSIP, SEDOL and FIGI check digits: validate the check digit of a financial security identifier (ISIN per ISO 6166). Returns the verdict, the computed correct check character, and for an ISIN the issuing country prefix and the embedded NSIN. Also builds an ISIN from a country code plus a 9-character NSIN. Format and checksum only, no security master lookup.
Offering
- Provider
- api.duoleads.com
- Method
- GET
- Offering type
- Api Endpoint
- Transport type
- http
- Category
- Financial Analysis
- Delivery
- Not provided
- Pricing model
- Not provided
- x402 version
- 2
Endpoint context
- URL
https://api.duoleads.com/v1/id/security- MIME type
- application/json
- First seen
- 2026-10-16T01:50:38.788Z
- Last seen
- Tags
- isin, isin-validator, cusip, identifiers, Validation
Payment pricing
x402 payment terms are the authoritative price for calling this endpoint.
- Payment option 1
- 0.05 USDC
Atomic price: 50000 · Network: eip155:8453 · Asset: USDC · Scheme: exact
Raw x402 terms
[
{
"scheme": "exact",
"network": "eip155:8453",
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"amount": "50000",
"payTo": "0xCD673f7e1daD254347AEab6be0DEFe8b9C6b3A39"
}
]Observed health
- Status
- Healthy
- Latest latency
- 43 ms
- Average latency
- 6651 ms
- HTTP status
- 402
- Last checked
- Reachability
- 91.7% over 12 checks
Latency is measured to the first response headers. A reachable result does not verify response accuracy or merchant identity.
Input schema
{
"type": "object",
"properties": {
"type": {
"type": "string",
"const": "http"
},
"method": {
"type": "string",
"enum": [
"GET"
]
},
"queryParams": {
"type": "object",
"properties": {
"op": {
"type": "string",
"description": "validate (default) or build-isin.",
"enum": [
"validate",
"build-isin"
],
"maxLength": 64,
"default": "validate"
},
"value": {
"type": "string",
"description": "ISIN, CUSIP, SEDOL or FIGI to validate. Required when op=validate.",
"maxLength": 24
},
"country": {
"type": "string",
"description": "ISO 3166-1 alpha-2 code or XS. Required when op=build-isin.",
"maxLength": 16
},
"nsin": {
"type": "string",
"description": "Exactly 9 alphanumeric characters. Required when op=build-isin.",
"maxLength": 64
}
},
"required": []
}
},
"required": [
"type",
"method"
],
"additionalProperties": false
}Output schema
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"method": {
"enum": [
"GET"
],
"type": "string"
},
"queryParams": {
"properties": {
"country": {
"description": "ISO 3166-1 alpha-2 code or XS. Required when op=build-isin.",
"maxLength": 16,
"type": "string"
},
"nsin": {
"description": "Exactly 9 alphanumeric characters. Required when op=build-isin.",
"maxLength": 64,
"type": "string"
},
"op": {
"default": "validate",
"description": "validate (default) or build-isin.",
"enum": [
"validate",
"build-isin"
],
"maxLength": 64,
"type": "string"
},
"value": {
"description": "ISIN, CUSIP, SEDOL or FIGI to validate. Required when op=validate.",
"maxLength": 24,
"type": "string"
}
},
"required": [],
"type": "object"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"properties": {
"data": {
"properties": {
"algorithm": {
"type": [
"string",
"null"
]
},
"check_char": {
"type": [
"string",
"null"
]
},
"check_char_ok": {
"type": "boolean"
},
"country": {
"type": [
"string",
"null"
]
},
"isin": {
"type": "string"
},
"normalised": {
"type": "string"
},
"nsin": {
"type": [
"string",
"null"
]
},
"reason": {
"type": [
"string",
"null"
]
},
"type": {
"type": "string"
},
"valid": {
"type": "boolean"
}
},
"type": "object"
},
"meta": {
"properties": {
"computed_at": {
"description": "RFC 3339 UTC with milliseconds",
"type": "string"
},
"deterministic": {
"type": "boolean"
},
"disclaimer": {
"type": "string"
},
"price_usd": {
"type": "string"
},
"request_id": {
"type": "string"
},
"sources": {
"items": {
"required": [
"id",
"version",
"published"
],
"type": "object"
},
"type": "array"
}
},
"required": [
"request_id",
"computed_at",
"price_usd",
"deterministic",
"disclaimer"
],
"type": "object"
},
"ok": {
"const": true
},
"route": {
"const": "/v1/id/security"
},
"version": {
"type": "string"
}
},
"required": [
"ok",
"route",
"version",
"data",
"meta"
],
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}