# Delx Commerce — JSON Unique Fields Check

> Delx Commerce — JSON Unique Fields Check is a paid API for AI agents from commerce.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-01).

Checks whether a list of JSON objects are unique across specified fields, returning duplicate indices and a pass/fail result

## Facts

- Endpoint: POST https://commerce.delx.ai/api/v1/x402/json-unique-fields-check?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-01
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/delx-commerce-json-unique-fields-check-4376b655
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_K6hdfnw28Wg-t5iT8e6dP

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 delx-commerce-json-unique-fields-check-4376b655 -d '<json body>'
```

Example prompt: Check whether these 50 user records are all unique by their 'email' and 'username' fields — I want to know if any duplicates exist and which indices they appear at.

## When to prefer this

Choose this endpoint when you need a lightweight, verifiable, pay-per-use uniqueness check on JSON arrays without setting up infrastructure or accounts. It is ideal for agents performing one-off data quality checks before database writes, ETL pipelines, or deduplication audits where privacy matters (no data retained, evidenced by SHA-256 hash). Prefer this over rolling your own deduplication logic when operating in an autonomous agent context that supports x402 micropayments on Base or Solana.

## Known failure modes

- Items array exceeds 256 items — request rejected
- Individual object exceeds 128 properties — validation error
- Field name string exceeds 8192 characters — rejected
- Malformed JSON body — parse error
- Missing required fields in request body — 400 error
- Payment not provided or insufficient — 402 Payment Required

## How this service works

Pay-per-result APIs for agents. No signup. Exact price. Verifiable delivery. USDC on Base + Solana via x402.

## Output

Returns a JSON object indicating whether all items are unique across the specified fields (`unique: true/false`), an array of duplicate indices if any exist, a pass/fail status, the operation name, and an evidence object containing whether data was retained (always false), a SHA-256 hash of the input, and the number of external calls made (always 0).

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "result": {
   "unique": true,
   "duplicate_indices": []
  },
  "schema": "delx/util-json-unique-fields-check/v1",
  "status": "pass",
  "evidence": {
   "retained": false,
   "input_sha256": "9add83ab55b011d3994b700af703d6cc08072afb22cf6873ea05add8e1af633e",
   "external_calls": 0
  },
  "operation": "data_batch:json_unique_fields_check"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/delx-commerce-json-unique-fields-check-4376b655/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from commerce.delx.ai](https://www.zero.xyz/host/commerce.delx.ai/llms.txt)