# Delx Commerce Citation Extractor

> Delx Commerce Citation Extractor is a paid API for AI agents from commerce.delx.ai, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-01).

Extracts DOI identifiers and URLs from arbitrary text using pattern matching, returning structured lists without fetching the links

## Facts

- Endpoint: POST https://commerce.delx.ai/api/v1/x402/citation-extract?utm_source=zero.xyz
- Price: $0.003/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-citation-extractor-0e8e0389
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_12gldwT0eoRGZIYf9bqxR

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-citation-extractor-0e8e0389 -d '<json body>'
```

Example prompt: Pull out all the DOIs and URLs from this text for me: 'Recent work (doi:10.1000/xyz123) builds on methods from https://example.com/paper and further references in doi:10.9999/abc456.'

## When to prefer this

Choose this endpoint when you need lightweight, pattern-based extraction of DOIs and URLs from text without any network fetching of those links. It is ideal for preprocessing academic papers, bibliographies, or documents to enumerate references cheaply ($0.003/call) and without signup. Prefer alternatives if you need link validation, full-text retrieval of cited pages, or semantic citation parsing beyond raw pattern matching.

## Known failure modes

- Empty or whitespace-only text input returns zero DOIs and zero URLs with empty arrays
- Malformed DOI patterns that deviate from standard formatting may not be detected
- URLs without standard schemes (http/https) may be missed
- Very large text bodies may hit payload size limits
- Non-UTF-8 encoded text may cause parsing errors

## 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 containing a list of extracted DOIs, a list of extracted URLs, counts for each, the schema version identifier 'delx/util-citation-extract/v1', and an advisory note clarifying that links are not fetched — only their patterns are matched from the input text.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "text": {
   "type": "string",
   "description": "UTF-8 text to encode, chunk, index, or analyze (caller-supplied only)."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "dois": [
   "10.1000/xyz123"
  ],
  "urls": [
   "https://example.com/a"
  ],
  "schema": "delx/util-citation-extract/v1",
  "advisory": "Pattern harvest only; links are not fetched.",
  "doi_count": 1,
  "url_count": 1
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/delx-commerce-citation-extractor-0e8e0389/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)