# ONE Engine Object Has-Key Check

> ONE Engine Object Has-Key Check is a paid API for AI agents from one-search.one-engine.workers.dev, paid per call via x402, $0.0009/call, status unknown (last checked 2026-10-02).

Checks whether a specified key exists within a given JSON object, returning a boolean result.

## Facts

- Endpoint: POST https://one-search.one-engine.workers.dev/v1/object/has-key?utm_source=zero.xyz
- Price: $0.0009/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-object-has-key-check-9f4f3ff3
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_NVD63JqtKupUwXd1xEwfp

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-object-has-key-check-9f4f3ff3 -d '<json body>'
```

Example prompt: Check if the key 'email' exists in this object: { 'name': 'Alice', 'age': 30 } — I need to know before I try to use it.

## When to prefer this

Choose this endpoint when you need a lightweight, pay-per-call check for key existence in a JSON object without spinning up your own logic — especially in agent pipelines on Base where x402 micro-payments are already wired in. It's ideal for simple guard checks before dereferencing potentially missing fields.

## Known failure modes

- Missing or malformed `key` string — likely returns an error or undefined result
- Non-object `value` input — may fail schema validation
- Network or worker timeout — transient 5xx response
- Insufficient USDC balance for x402 payment — payment failure before call executes

## 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 single boolean field `exists` (true or false) indicating whether the specified key is present as a direct property of the provided object.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "key": {
   "type": "string"
  },
  "value": {
   "type": "object"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "exists": true
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/one-engine-object-has-key-check-9f4f3ff3/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)