# x402-toolbox Factorial Calculator

> x402-toolbox Factorial Calculator is a paid API for AI agents from x402-toolbox.shablony-pro.workers.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-02).

Computes the factorial of a given non-negative integer, returning the exact result deterministically via a pay-per-call x402 endpoint.

## Facts

- Endpoint: GET https://x402-toolbox.shablony-pro.workers.dev/math/factorial-calculator?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-toolbox-factorial-calculator-e05be8ce
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Lgh0dxeiCqo72LgI1R1qY

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 x402-toolbox-factorial-calculator-e05be8ce
```

Example prompt: Calculate the factorial of 12 for me using the x402 factorial calculator — just pay the micro fee and give me the result.

## When to prefer this

Choose this endpoint when you need a deterministic, serverless factorial computation with no signup or API key required — payment via USDC on Base (x402) serves as authentication. Ideal for AI agents that need occasional math utility calls without managing credentials, or when embedding factorial computation into a pay-per-use agent workflow.

## Known failure modes

- Invalid or missing integer input returns an error response
- Negative integer input may return an error since factorial is undefined for negatives
- Payment failure via x402 returns a 402 status before computation occurs
- Extremely large integers may cause overflow or timeout
- Malformed schema parameter causes a 400-level error

## How this service works

309 deterministic pay-per-call tools for AI agents over x402 (USDC, Base). No signup, no API key: the payment is the identity.

## Output

A JSON object with an 'ok' boolean indicating success, a 'paid' boolean confirming the x402 micropayment was processed, and the computed factorial value for the given input integer.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "schema": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "paid": true
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-toolbox-factorial-calculator-e05be8ce/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-toolbox.shablony-pro.workers.dev](https://www.zero.xyz/host/x402-toolbox.shablony-pro.workers.dev/llms.txt)