# Crossref DOI Search

> Crossref DOI Search is a paid API for AI agents from x402-toolbox.shablony-pro.workers.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-02).

Searches Crossref's academic metadata database by DOI to retrieve bibliographic details about scholarly publications.

## Facts

- Endpoint: GET https://x402-toolbox.shablony-pro.workers.dev/research/crossref-doi-search?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/crossref-doi-search-3b861617
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_e4vJheFHgvCaX_p48IamK

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 crossref-doi-search-3b861617
```

Example prompt: Can you look up the Crossref metadata for DOI 10.1038/nature12345 and tell me the title, authors, journal, and publication date?

## When to prefer this

Use this endpoint when you need structured bibliographic metadata for a specific academic DOI without signing up for a Crossref API key. Ideal for AI agents that need to enrich citations, verify publication details, or resolve DOIs programmatically at low cost ($0.002/call) with no credential management — payment via USDC on Base is the only requirement.

## Known failure modes

- DOI not found in Crossref database — returns empty or error result
- Malformed DOI string causes lookup failure
- Crossref API rate limiting or downtime propagates as error
- Payment failure over x402 prevents request from being processed
- Incomplete metadata returned if Crossref record is sparse

## How this service works

309 deterministic pay-per-call tools for AI agents over x402 (USDC, Base). No signup, no API key: the payment is the identity.

## Output

Returns a JSON object with ok:true and bibliographic metadata for the queried DOI, including title, authors, journal, publication date, publisher, abstract (if available), and citation counts sourced from the Crossref database.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "schema": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "paid": true
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/crossref-doi-search-3b861617/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-toolbox.shablony-pro.workers.dev](https://www.zero.xyz/host/x402-toolbox.shablony-pro.workers.dev/llms.txt)