# Irish PPSN Validator (Offline)

> Irish PPSN Validator (Offline) is a paid API for AI agents from toll402.dev, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).

Validates an Irish Personal Public Service Number (PPSN) by checking its format and verifying the check letter using the official mod-23 weighted-sum algorithm, entirely offline.

## Facts

- Endpoint: POST https://toll402.dev/v1/t/ppsn_ie_validate
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/irish-ppsn-validator-offline-77bb2cd8
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_XZAkyC6lK0n1fpEVn-lrl

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 irish-ppsn-validator-offline-77bb2cd8 -d '<json body>'
```

Example prompt: Can you check whether the Irish PPSN '1234567T' is valid — verify both the format and the check letter?

## When to prefer this

Choose this endpoint when you need a fast, offline, deterministic validation of an Irish PPSN with no external data dependencies. It is ideal for pre-submission checks, user registration flows, or data-quality pipelines where you only need format and check-letter correctness — not identity lookup or cross-referencing against a government database.

## Known failure modes

- PPSN with incorrect number of digits rejected as format error
- Invalid check letter (mod-23 mismatch) returns validation failure
- Unsupported trailing modifier letter (anything other than A or H) rejected
- Empty or missing ppsn field returns a schema validation error
- Non-string input types may cause a 400-level error

## How this service works

Offline validator for an Irish PPSN (Personal Public Service Number): checks the 7-digit + 1 check-letter (+ optional trailing 'A' or 'H' modifier letter) format and verifies the check letter using the published mod-23 weighted-sum algorithm (weights 8..2, optional modifier adds 9 or 72). Processes a single PPSN only; no network access or storage.

## Output

Returns a validation result indicating whether the submitted PPSN string passes both the format check (7 digits followed by a check letter and optional 'A' or 'H' modifier) and the mod-23 weighted-sum check-letter algorithm. Likely includes a boolean valid/invalid status and possibly a reason or error detail on failure.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "type": "object",
     "required": [
      "ppsn"
     ],
     "properties": {
      "ppsn": {
       "type": "string",
       "description": "PPSN string, e.g. 1234567T or 1234567TA"
      }
     },
     "additionalProperties": false
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/irish-ppsn-validator-offline-77bb2cd8/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from toll402.dev](https://www.zero.xyz/host/toll402.dev/llms.txt)