# JSON Array Project Keys

> JSON Array Project Keys is a paid API for AI agents from api.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).

Projects (selects) a specified subset of keys from every object in a JSON array, returning only the requested fields from each row

## Facts

- Endpoint: POST https://api.delx.ai/api/v1/x402/json-array-project-keys
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/json-array-project-keys-43802104
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ic2lC-r9Jp9y7yXPoQwHq

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 json-array-project-keys-43802104 -d '<json body>'
```

Example prompt: Take this array of user records and return only the 'id', 'email', and 'status' fields from each object — strip everything else out.

## When to prefer this

Choose this endpoint when an agent needs to deterministically strip a JSON array down to a defined set of keys before handing data to a downstream tool with a strict schema contract. It is preferable to writing inline transformation logic when you need a versioned, auditable result with counts, or when you want a stateless in-memory operation with no data retention guarantees to worry about. Ideal for agent pipelines where structured data must conform to a narrower schema at the next step.

## Known failure modes

- Keys not present in source objects result in those keys being omitted or returned as null/undefined per contract
- Input array exceeding 256 items is rejected
- Object with more than 128 properties may be rejected
- Empty keys array returns empty objects for each row
- Malformed input JSON results in validation error
- Payment failure (x402) prevents execution

## How this service works

JSON Array Project Keys: JSON Array Project Keys projects selected keys from every object row from bounded caller-supplied values without an external provider. Call JSON Array Project Keys before an agent hands structured data or a batch plan to a downstream tool with a stricter contract. Returns the bounded transformation or validation finding with counts, normalized values, and a versioned result contract for JSON Array Project Keys as versioned deterministic JSON. Price: $0.001 USDC via x402…

## Output

Returns a versioned deterministic JSON object containing the projected array (each object containing only the requested keys), row counts, normalized values, and a versioned result contract — all computed in-memory without data retention.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "keys": {
   "type": "array",
   "items": {
    "type": "string",
    "maxLength": 8192
   },
   "maxItems": 256,
   "description": "Keys supplied to JSON Array Project Keys; used only for this bounded calculation and processed in memory without retention."
  },
  "items": {
   "type": "array",
   "items": {
    "type": "object",
    "maxProperties": 128,
    "additionalProperties": true
   },
   "maxItems": 256,
   "description": "Items supplied to JSON Array Project Keys; used only for this bounded calculation and processed in memory without retention."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "result": {
   "keys": [
    "id",
    "name"
   ],
   "items": [
    {
     "id": 1,
     "name": "A"
    }
   ]
  },
  "schema": "delx/util-json-array-project-keys/v1",
  "status": "pass",
  "evidence": {
   "retained": false,
   "input_sha256": "cf97ec299457d0d7e866c72dd379cccee1d633725ce65b3c091d637611c798a6",
   "external_calls": 0
  },
  "operation": "data_batch:json_array_project_keys"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/json-array-project-keys-43802104/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.delx.ai](https://www.zero.xyz/host/api.delx.ai/llms.txt)