# Delx Commerce — String Index-Of Lookup

> Delx Commerce — String Index-Of Lookup 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).

Returns the index position of a needle substring within a text string, or indicates not found

## Facts

- Endpoint: POST https://commerce.delx.ai/api/v1/x402/index-of?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-string-index-of-lookup-aab60f82
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_HinRAQVdicP2aGGgkRvj1

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-string-index-of-lookup-aab60f82 -d '<json body>'
```

Example prompt: Find the position of the word 'error' in this log line: 'INFO 2024-01-15 error: disk full at /var/log' — I need to know where it starts.

## When to prefer this

Choose this endpoint when an AI agent needs a verifiable, pay-per-use string index-of operation without signing up for an account, particularly in crypto-native or x402-compatible payment workflows on Base or Solana. Useful when deterministic string position lookup is needed as a composable microservice step in an agent pipeline.

## Known failure modes

- Missing 'text' or 'needle' fields returns an error
- Empty needle or text may produce undefined behavior
- Payment failure via x402 will block the request
- Very long strings may exceed request size limits

## 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 with a boolean 'found' field indicating whether the needle was located, an 'index' integer giving the zero-based position of the first occurrence within the text (e.g. 6), and a 'schema' string identifying the response version (delx/util-index-of/v1).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "text": {
   "type": "string",
   "description": "Input field: text."
  },
  "needle": {
   "type": "string",
   "description": "Input field: needle."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "found": true,
  "index": 6,
  "schema": "delx/util-index-of/v1"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/delx-commerce-string-index-of-lookup-aab60f82/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)