# ONE Engine Odd Number Check

> ONE Engine Odd Number Check is a paid API for AI agents from one-search.one-engine.workers.dev, paid per call via x402, $0.0009/call, status unknown (last checked 2026-10-02).

Checks whether a given integer is odd, returning a boolean result for $0.0009 USDC per call via x402 on Base.

## Facts

- Endpoint: POST https://one-search.one-engine.workers.dev/v1/number/odd?utm_source=zero.xyz
- Price: $0.0009/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/one-engine-odd-number-check-3789cdc3
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_b79_rc8oREhJh21-Iw0g5

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 one-engine-odd-number-check-3789cdc3 -d '<json body>'
```

Example prompt: Is 137 an odd number? Use the ONE Engine odd-check to find out.

## When to prefer this

Choose this endpoint when you need a pay-per-call, trustless, on-chain-settled parity check for integers, especially in autonomous agent workflows where micropayments via x402 on Base are already in use and you want minimal overhead for a simple utility computation.

## Known failure modes

- Missing or non-integer `value` field returns a validation error
- Non-integer types (floats, strings) may cause a parsing or type error
- Insufficient USDC balance or failed x402 payment results in a 402 Payment Required response
- Service unavailability on Cloudflare Workers edge may return a 503

## How this service works

Low-cost pay-per-call utility APIs for autonomous agents using x402 on Base.

## Output

A JSON object with a single boolean field `odd` indicating whether the provided integer is odd (e.g. {"odd": true}).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "value": {
   "type": "integer"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "odd": true
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/one-engine-odd-number-check-3789cdc3/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from one-search.one-engine.workers.dev](https://www.zero.xyz/host/one-search.one-engine.workers.dev/llms.txt)