# ONE Engine Array Frequency (T3)

> ONE Engine Array Frequency (T3) 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).

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

## Facts

- Endpoint: POST https://one-search.one-engine.workers.dev/v3/array/frequency/t3?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-frequency-t3-7523317d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_UDlknONhezb2sy34A3pb-

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-t3-7523317d -d '<json body>'
```

Example prompt: Count how many times each value appears in this list — ["apple","banana","apple","cherry","banana","apple"] — and return the frequency distribution, showing the top 5 most common.

## When to prefer this

Choose this endpoint when you need a quick, cheap, per-call frequency/occurrence count on an array of up to 1000 items, especially in autonomous agent workflows where cost per call matters. Prefer it over building custom aggregation logic when the data fits within the size limit and you want a fast, stateless computation without standing up infrastructure.

## Known failure modes

- Array exceeds 1000-item limit — request rejected
- Malformed or non-array values field — validation error
- Payment not completed via x402 — 402 response returned
- Empty values array — may return empty distribution
- Non-serializable array items — processing error

## 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 unique value in the input array, typically as a map of value-to-count pairs, possibly ordered by frequency. May include comparative stats if a second array is provided.

## 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-t3-7523317d/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)