# SiteCheck Web Intel – Crossref Academic Paper Lookup

> SiteCheck Web Intel – Crossref Academic Paper Lookup is a paid API for AI agents from api.webintel-api.workers.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-24).

Looks up a scholarly paper by DOI via Crossref's public REST API, returning title, authors, journal, publication date, cited-by count, publisher, and link.

## Facts

- Endpoint: GET https://api.webintel-api.workers.dev/api/search/crossref-academic-paper?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-24
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/sitecheck-web-intel-crossref-academic-paper-lookup-7ed72654
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Rc0cyfHruLkQVg8wh2TP5

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 sitecheck-web-intel-crossref-academic-paper-lookup-7ed72654
```

Example prompt: Can you look up the paper with DOI 10.1038/nature12373 and tell me the title, authors, journal, publication date, and how many times it's been cited?

## When to prefer this

Use this endpoint when you have a specific DOI and need authoritative bibliographic metadata from Crossref — particularly title, authors, journal, publication date, citation count, and publisher. Prefer this over general web search when you need structured, machine-readable academic metadata rather than a full-text search across papers.

## Known failure modes

- DOI not found in Crossref database returns 404
- Malformed or missing DOI parameter causes request failure
- Some papers may have incomplete metadata (e.g. missing cited-by count or authors)
- Network or upstream Crossref API timeout

## How this service works

Crossref DOI lookup (public REST API, no key): title, authors, journal, publication date, cited-by count, publisher and link for one paper. Unknown DOIs return 404.

## Output

Returns structured metadata for the requested paper including: full title, list of authors, journal/venue name, publication date, cited-by count, publisher name, and a URL link to the paper. Returns 404 if the DOI is not found in Crossref.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "doi"
     ],
     "properties": {
      "doi": {
       "type": "string",
       "description": "DOI such as 10.1038/nature12373"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/sitecheck-web-intel-crossref-academic-paper-lookup-7ed72654/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.webintel-api.workers.dev](https://www.zero.xyz/host/api.webintel-api.workers.dev/llms.txt)