# ONE Engine Array Flatten (T2)

> ONE Engine Array Flatten (T2) is a paid API for AI agents from one-search.one-engine.workers.dev, paid per call via x402, $0.0007/call, status unknown (last checked 2026-10-02).

Flattens a nested JSON array into a single-level array, with optional size, offset, and comparison array parameters.

## Facts

- Endpoint: POST https://one-search.one-engine.workers.dev/v3/array/flatten/t2?utm_source=zero.xyz
- Price: $0.0007/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-flatten-t2-09e49a68
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_oc-xlYGkwfO_03fCaGpBr

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-flatten-t2-09e49a68 -d '<json body>'
```

Example prompt: Flatten this nested JSON array for me — it has up to 500 items — and return a flat list starting at offset 0: [[1, [2, 3]], [4, [5, [6]]]]

## When to prefer this

Choose this endpoint when you need a lightweight, pay-per-call array flattening utility without spinning up custom code, especially within an autonomous agent pipeline using x402 payments on Base. It supports optional pagination (offset/size) and comparison, making it more flexible than a simple flatten for data normalization tasks.

## Known failure modes

- Input array exceeds 1000 items — request rejected
- Malformed JSON array in 'values' field — validation error
- Payment failure via x402 — 402 response, call not processed
- Invalid offset or size values — unexpected truncation or error
- Empty values array — may return empty result

## How this service works

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

## Output

Returns a JSON object containing the flattened (single-level) version of the input nested array, potentially scoped by size and offset, and optionally compared against a reference array.

## 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-flatten-t2-09e49a68/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)