# ONE Engine Array Contains Check

> ONE Engine Array Contains Check is a paid API for AI agents from one-search.one-engine.workers.dev, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-02).

Checks whether a given value exists within an array and returns the result along with the index of the match.

## Facts

- Endpoint: POST https://one-search.one-engine.workers.dev/v1/array/contains?utm_source=zero.xyz
- Price: $0.001/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-array-contains-check-0c8a1862
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_lA5TE21zIW9rX-oO257CX

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-array-contains-check-0c8a1862 -d '<json body>'
```

Example prompt: Check if the value 'banana' is contained in this array: ['apple', 'banana', 'cherry', 'date'] — I need to know if it's there and what index it's at.

## When to prefer this

Use this endpoint when you need a lightweight, pay-per-call array membership check without spinning up any compute infrastructure. Ideal for AI agents that need to verify inclusion of a value in a list as part of a workflow and want a cheap ($0.001 USDC), real-time, stateless primitive accessible over HTTP with x402 micropayments on Base.

## Known failure modes

- Missing 'value' or 'values' fields returns a validation error
- Non-array type for 'values' may cause a 400 error
- Payment failure via x402 protocol results in a 402 response blocking the call
- Empty array input may return contains: false with index: -1

## How this service works

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

## Output

Returns a JSON object with a boolean 'contains' field indicating whether the value was found in the array, and an 'index' integer indicating the position of the first match (or -1/null if not found).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "value": {},
  "values": {
   "type": "array"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "index": 1,
  "contains": true
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/one-engine-array-contains-check-0c8a1862/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)