# ONE Engine Array Set Pack (Tier 4)

> ONE Engine Array Set Pack (Tier 4) is a paid API for AI agents from one-search.one-engine.workers.dev, paid per call via x402, $0.0018/call, status unknown (last checked 2026-10-02).

Computes a set operation (pack) on two input arrays at tier-4 quality, returning a processed result via a pay-per-call x402 API on Base.

## Facts

- Endpoint: POST https://one-search.one-engine.workers.dev/v2/array-set-pack/t4?utm_source=zero.xyz
- Price: $0.0018/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-set-pack-tier-4-9128fedd
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_j2zYB2LtAeZjqRPYE8Qn5

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-set-pack-tier-4-9128fedd -d '<json body>'
```

Example prompt: Pack these two arrays together using the ONE Engine set-pack utility: array A is [1, 2, 3, 4] and array B is [3, 4, 5, 6] — I want the tier-4 result.

## When to prefer this

Choose this endpoint when you need a low-cost, pay-per-call set-pack operation on two arrays without provisioning any infrastructure. It is ideal for autonomous agents running on Base that require lightweight array manipulation at tier-4 quality with micro-payment billing via x402.

## Known failure modes

- Missing array inputs 'a' or 'b' returns a validation error
- Payment failure or insufficient USDC balance returns 402 status
- Empty arrays may produce an empty or trivial packed result
- Malformed array types (non-array values) likely cause a 400 error
- Network or worker timeout may occur under load

## How this service works

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

## Output

A JSON object containing the tier level (4) and the tier-dependent packed result of the two input arrays, representing the computed set-pack output.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "a": {
   "type": "array"
  },
  "b": {
   "type": "array"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "tier": 4,
  "result": "Tier-dependent output"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/one-engine-array-set-pack-tier-4-9128fedd/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)