# ONE Engine Array Frequency (t4)

> ONE Engine Array Frequency (t4) is a paid API for AI agents from one-search.one-engine.workers.dev, paid per call via x402, $0.0015/call, status unknown (last checked 2026-10-02).

Computes the frequency distribution of elements in a JSON array, with optional comparison against a second array and configurable size/offset parameters.

## Facts

- Endpoint: POST https://one-search.one-engine.workers.dev/v3/array/frequency/t4?utm_source=zero.xyz
- Price: $0.0015/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-frequency-t4-44b83420
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_OzJvLKH-2JRouqn_yudoy

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-frequency-t4-44b83420 -d '<json body>'
```

Example prompt: Count how many times each value appears in this list and give me the frequency distribution: ["apple","banana","apple","cherry","banana","apple","cherry","cherry","banana","apple"] — limit results to the top 5.

## When to prefer this

Choose this endpoint when you need a fast, cheap ($0.0015 USDC) pay-per-call frequency/occurrence count over an array of up to 1000 elements, especially in an autonomous agent context that already handles x402 payments on Base. It is ideal for categorical data analysis, duplicate detection, or comparing element distributions across two datasets without standing up your own analytics infrastructure.

## Known failure modes

- Array exceeds 1000-item limit — request rejected
- Malformed or non-array values field — validation error
- Payment not included or insufficient — 402 response requiring x402 payment on Base
- Missing required values field — schema validation error
- Non-serializable array elements may cause processing errors

## How this service works

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

## Output

Returns an object containing frequency counts for each distinct element in the input array, showing how many times each value appears. When a comparison array is provided, the response includes comparative frequency data across both arrays. Results may be paginated via size and offset parameters.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "values"
 ],
 "properties": {
  "size": {
   "type": "integer"
  },
  "other": {
   "type": "array",
   "description": "Optional comparison array"
  },
  "offset": {
   "type": "integer"
  },
  "values": {
   "type": "array",
   "description": "JSON array with at most 1000 items"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "additionalProperties": true
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/one-engine-array-frequency-t4-44b83420/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)