# ONE Engine Array Head – First 16 Items (Tier 1)

> ONE Engine Array Head – First 16 Items (Tier 1) is a paid API for AI agents from one-search.one-engine.workers.dev, paid per call via x402, $0.0005/call, status unknown (last checked 2026-10-15).

Returns the first 16 elements of a submitted array, with Tier 1 richer diagnostic metadata included in the response.

## Facts

- Endpoint: POST https://one-search.one-engine.workers.dev/v6/array-head/items-16/t1?utm_source=zero.xyz
- Price: $0.0005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/one-engine-array-head-first-16-items-tier-1-f04b313a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_MZbHXIISHfnQD0flq1wiJ

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-head-first-16-items-tier-1-f04b313a -d '<json body>'
```

Example prompt: I have a long list of items and I need just the first 16 entries — can you slice the array head for me and include the diagnostic details?

## When to prefer this

Choose this endpoint when you need a deterministic, cheap, stateless head-slice of exactly 16 items from an array — especially when you also want lightweight diagnostic metadata (Tier 1) about the operation. It is ideal for agent workflows that need to preview, paginate, or sample the leading elements of a list without processing the full dataset. Prefer it over generic slicing logic when you want a pay-per-call micro-utility with audit diagnostics baked in.

## Known failure modes

- Empty array input returns an empty result set
- Malformed JSON body causes a 400 parse error
- Array with fewer than 16 items returns all available items (no error)
- Payment failure or missing x402 header results in a 402 Payment Required response
- Oversized payload may trigger request size limits

## How this service works

Return first 16 array items. Tier 1/10 adds richer diagnostics.

## Output

A JSON response containing up to 16 elements taken from the start of the submitted array, plus Tier 1 diagnostic metadata such as total input length, slice boundaries, and structural information about the extracted subset.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/one-engine-array-head-first-16-items-tier-1-f04b313a/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)