Crossref API

Base URL

https://api.crossref.org

Authentication

No API key. Supplying `mailto=you@example.com` puts you in the faster 'polite pool'.

Rate limit

No hard limit, but the polite pool gets better service. Bulk users should use the data dumps.

Pricing

Free open metadata.

CORS

Enabled — callable directly from browser JavaScript

Official docs

Read the docs

Every request below was executed against the live API on 20 Aug 2026, and the response shown is the real body it returned — not an illustration.

curl 'https://api.crossref.org/works?rows=1&select=DOI,title'

const res = await fetch("https://api.crossref.org/works?rows=1&select=DOI,title");
if (!res.ok) throw new Error(`Request failed: ${res.status}`);
const data = await res.json();
console.log(data);

import requests

res = requests.get("https://api.crossref.org/works?rows=1&select=DOI,title", timeout=20)
res.raise_for_status()
print(res.json())

{
  "status": "ok",
  "message-type": "work-list",
  "message-version": "1.0.0",
  "message": {
    "facets": {},
    "total-results": 185622127,
    "items": [
      {
        "DOI": "10.1007/978-3-658-17671-6_18-1",
        "title": [
          "Soziale Innovation"
        ]
      }
    ],
    "items-per-page": 1,
    "query": {
      "start-index": 0,
      "search-terms": null
    }
  }
}

message.total-resultsinteger

Total works matching the query.

message.items[].DOIstring

The work's DOI — the stable identifier.

message.items[].titlearray

Title, as an array even when there is one.

message.items[].authorarray

Authors with given/family names and ORCID where known.

message.items[].container-titlearray

Journal or book title.

message.items[].is-referenced-by-countinteger

Citation count as tracked by Crossref.

message.items[].referencearray

The work's own reference list, when deposited.

• Resolve a DOI to full bibliographic metadata
• Build a citation manager or reference tool
• Analyse publication and citation trends
• Enrich a research repository with authoritative metadata

If Crossref does not fit, these science & space apis cover similar ground. Every one was called before publishing, and each links to its own reference page with a working curl command and the response it returned.