# Delx List Len

> Delx List Len is a paid API for AI agents from api.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-13).

Returns the length of a JSON array or a separator-delimited string list as a deterministic integer

## Facts

- Endpoint: POST https://api.delx.ai/api/v1/x402/list-len
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/delx-list-len-3b98bd52
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_e_QnEI5FNca3vOaQ8DltR

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-list-len-3b98bd52 -d '<json body>'
```

Example prompt: How many items are in this array: ["apple", "banana", "cherry", "date"]? Just give me the count.

## When to prefer this

Use this endpoint when an agent needs a quick, deterministic count of array or list elements as a lightweight preflight step — especially when avoiding shipping extra code, when operating in a cost-sensitive micro-task context at $0.001 USDC, or when chaining with other Delx utility routes. Prefer over custom code when keeping the agent runtime lean and stateless.

## Known failure modes

- Invalid or missing 'items' field returns an error response
- Non-array input that cannot be parsed as a list may return an error
- Malformed JSON in the request body results in a 400-level error
- Payment not included or insufficient USDC triggers x402 payment-required response

## How this service works

Return length of a JSON array or separator-split string list — first-party local utility for agent preflight and proven micro-utils expansion. Returns deterministic machine-readable JSON for $0.001 USDC via x402 on Base. Execution is first-party, local-only, stateless, and memory-only with no paid upstream, no input retention, no web search, no live RPC, and no mediagen. Results are advisory; the caller owns authorization, budgets, and production controls. Sibling of Delx routes that already co…

## Output

Returns a deterministic JSON object containing the integer count of elements in the provided array or separator-split string. The response is machine-readable, stateless, and advisory — no data is retained after the call.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "items": {
   "type": "array",
   "description": "Input field: items."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "empty": false,
  "length": 3,
  "sample": [
   "a",
   "b",
   "c"
  ],
  "schema": "delx/util-list-len/v1"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/delx-list-len-3b98bd52/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)