# ONE Engine Object Size

> ONE Engine Object Size 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).

Returns the number of properties (keys) in a given JSON object.

## Facts

- Endpoint: POST https://one-search.one-engine.workers.dev/v1/object/size?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-size-74bf6ec8
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_NA6Rkto16TZoKfCNDq5UC

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-size-74bf6ec8 -d '<json body>'
```

Example prompt: How many properties does this object have: {"name": "Alice", "age": 30, "city": "NYC"}? Use ONE Engine to count the keys for me.

## When to prefer this

Choose this endpoint when you need a fast, cheap, single-call utility to count the number of top-level keys in a JSON object without running local code. Ideal for AI agents that need lightweight introspection of dynamic payloads without spinning up a code execution environment. At $0.0009 USDC per call, it is cost-effective for high-frequency agent workflows.

## Known failure modes

- Non-object input (e.g. array or primitive) may return an unexpected count or error
- Missing or malformed `value` field in the request body may result in a 400 error
- Empty object returns count of 0, which is valid but may be unexpected
- Network or payment failure (x402) results in a 402 Payment Required response

## 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 `count` field containing the integer number of top-level properties in the submitted object (e.g. {"count": 2}).

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "count": 2
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/one-engine-object-size-74bf6ec8/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)