# Agent402 ISIN Validator

> Agent402 ISIN Validator is a paid API for AI agents from agent402.co.uk, paid per call via x402, $0.001/call, status down (last checked 2026-10-12).

Validates a 12-character ISIN string against ISO 6166 format rules and Luhn check digit — returns country code, NSIN, and per-check results.

## Facts

- Endpoint: POST https://agent402.co.uk/v1/validate/isin?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: down
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agent402-isin-validator-c8824699
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Q928W9oNuNrXmv_tL6Gri

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability agent402-isin-validator-c8824699 -d '<json body>'
```

Example prompt: Can you check whether US0378331005 is a valid ISIN — I need to confirm the format and Luhn checksum are correct before I submit this trade?

## When to prefer this

Choose this endpoint when you need a fast, cheap ($0.001) structural and checksum gate on an ISIN before submitting to a downstream system, and you do NOT need live exchange listing confirmation or CUSIP/SEDOL registry lookup. It is ideal for data pipeline scrubbing, form validation, or compliance pre-checks where ISO 6166 format correctness and Luhn integrity are sufficient.

## Known failure modes

- Input ISIN is not exactly 12 characters — returns valid:false with format failure
- Non-alphanumeric characters in ISIN — format check fails
- Correct format but wrong Luhn check digit — valid_format:true but valid_checksum:false and valid:false
- Unknown or invalid country prefix — may still pass checksum but country field reflects raw prefix
- Missing or empty isin field — likely 4xx error or validation failure response
- Payment failure (402) if x402 authorization header is not provided or insufficient USDC balance

## How this service works

Don't burn tokens on deterministic work. Go/no-go jobs first: payout preflight, text firewall (PII/secrets), budget check — then rails, calendars, finmath. x402 USDC on Base. UK + global. agent402.co.uk — not agent402.tools. $0.001–$0.002 USDC on Base. No API keys.

## Output

A JSON object with: `valid` (overall pass/fail boolean), `valid_format` (ISO 6166 12-char structure check), `valid_checksum` (Luhn digit check), `country` (2-letter ISO country code from the ISIN prefix), `nsin` (the 9-character national securities identifier portion), and `provenance.depth` indicating this is a local checksum-only check (not a live registry or exchange lookup).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "isin": {
   "type": "string",
   "description": "12-char ISIN (e.g. US0378331005)"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "nsin": "037833100",
  "valid": true,
  "country": "US",
  "provenance": {
   "depth": "checksum_only"
  },
  "valid_format": true,
  "valid_checksum": true
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agent402-isin-validator-c8824699/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agent402.co.uk](https://www.zero.xyz/host/agent402.co.uk/llms.txt)