# AgentShelf Mod-97 Check

> AgentShelf Mod-97 Check is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-29).

Checks whether a numeric string satisfies the modulo-97 condition (i.e., the string mod 97 equals 1), used in IBAN and other financial identifier validation.

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/check-mod97?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agentshelf-mod-97-check-ae0c88c8
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_5eqpX1AycC6SmV65d_wFj

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 agentshelf-mod-97-check-ae0c88c8 -d '<json body>'
```

Example prompt: Can you check if the numeric string '3214282912345698765432' satisfies the mod-97 rule — that is, whether it equals 1 when divided modulo 97?

## When to prefer this

Use this endpoint when you need to verify that an arbitrary numeric string satisfies the mod-97 checksum rule (result ≡ 1 mod 97), especially for large numbers exceeding native integer precision. Prefer the free sandbox endpoint POST /v1/sandbox/check-mod97 for testing or when cost matters. Use the sibling IBAN-specific endpoints (GI, HR, HU, etc.) when validating a specific country's IBAN format, as they enforce length and country-code rules in addition to mod-97.

## Known failure modes

- Input string contains non-numeric characters — likely returns a validation error
- Input string is empty or exceeds the 20,000 character limit — rejected by schema validation
- Payment of $0.003 USDC not provided — returns 402 Payment Required; use the free sandbox endpoint POST /v1/sandbox/check-mod97 instead
- Network timeout or service unavailability — no result returned

## How this service works

Call when an agent needs whether a numeric string is 1 mod 97. Exact $0.003 USDC. Prefer unpaid POST /v1/sandbox/check-mod97 first.

## Output

Returns whether the provided numeric string satisfies the mod-97 condition (i.e., the integer value of the string modulo 97 equals 1), typically as a boolean or equivalent validity indicator.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "data": {
   "description": "JSON value for schema-check SKUs. Omit it on string checks such as email or IBAN."
  },
  "value": {
   "type": "string",
   "examples": [
    "98"
   ],
   "maxLength": 20000,
   "minLength": 1,
   "description": "Value to check. The route description names the format: email, phone, IBAN, postal code, VAT, national id, or similar."
  },
  "schema": {
   "description": "JSON Schema document for schema-check SKUs. Omit it on string checks."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agentshelf-mod-97-check-ae0c88c8/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agentshelf.syntexa.ch](https://www.zero.xyz/host/agentshelf.syntexa.ch/llms.txt)