# Delx Commerce — JSON String Length Check

> Delx Commerce — JSON String Length Check is a paid API for AI agents from commerce.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-02).

Validates that specified string fields within a JSON object fall within defined minimum and maximum character length bounds.

## Facts

- Endpoint: POST https://commerce.delx.ai/api/v1/x402/json-string-length-check?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/delx-commerce-json-string-length-check-57477d89
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_l9fNEkdyHufsnpDb3qOUk

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-string-length-check-57477d89 -d '<json body>'
```

Example prompt: Check whether the 'username' and 'bio' fields in this JSON object meet my length requirements — username must be between 3 and 32 characters, and bio between 10 and 500 characters: {"username": "jo", "bio": "I love coding"}

## When to prefer this

Use this endpoint when you need a lightweight, pay-per-call, no-signup validation of JSON string field lengths with cryptographic verifiability (SHA-256 input hashing and no data retention guarantees). Prefer it over building custom validation logic when you want an auditable, agent-friendly microservice that returns structured pass/fail results. Ideal for agent pipelines that need to gate on data quality before downstream processing, especially when USDC micropayments via x402 are already integrated.

## Known failure modes

- Field names specified in 'fields' array do not exist in the provided object — returns pass with no violations since no matching fields found
- Non-string field values in the specified fields may not be evaluated correctly
- Input object exceeds 128 properties limit — request rejected
- Fields array exceeds 256 items — request rejected
- Missing or malformed minimum/maximum integers — undefined validation behavior
- Payment failure via x402 protocol — 402 response before computation occurs

## 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 result object indicating whether all specified string fields passed the length check, a list of any fields that failed (invalid_fields), an overall status ('pass' or 'fail'), and evidence metadata including a SHA-256 hash of the input for verifiability and confirmation that no data is retained.

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "result": {
   "passed": true,
   "invalid_fields": []
  },
  "schema": "delx/util-json-string-length-check/v1",
  "status": "pass",
  "evidence": {
   "retained": false,
   "input_sha256": "e61f8b4c6194a85d31be821c7ddcec01a240fe3d4b33cd76336131c6315185b6",
   "external_calls": 0
  },
  "operation": "data_batch:json_string_length_check"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/delx-commerce-json-string-length-check-57477d89/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)