# ONE Engine Array Join

> ONE Engine Array Join 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).

Joins an array of values into a single string using a specified separator character.

## Facts

- Endpoint: POST https://one-search.one-engine.workers.dev/v1/array/join?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-join-71cf3362
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_i985N2S5X5uiXFavR1nVI

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-join-71cf3362 -d '<json body>'
```

Example prompt: Join the array ["apple", "banana", "cherry"] into a single string using a comma and space as the separator.

## When to prefer this

Choose this endpoint when an AI agent needs a cheap, fast, pay-per-call string join operation without spinning up a compute environment or writing inline code. Ideal for autonomous agent pipelines on Base using x402 micropayments that need to format arrays as delimited strings for downstream processing, display, or CSV generation.

## Known failure modes

- Missing or empty `values` array may return an empty string or error
- Non-string values in the array may be coerced or cause unexpected output
- Missing `separator` field may default to empty string or return an error
- Payment failure via x402 will prevent the call from completing
- Malformed JSON request body will result in a 4xx error

## How this service works

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

## Output

Returns a JSON object with a `text` field containing all array values concatenated together using the specified separator string, e.g. {"text": "apple, banana, cherry"}.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "values": {
   "type": "array"
  },
  "separator": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "text": "ONE Engine"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/one-engine-array-join-71cf3362/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)