Crossref at https://api.crossref.org holds metadata for scholarly works registered with a DOI: titles, authors, journals, references, citation counts.
None. Adding [email protected] to requests puts you in Crossref's faster “polite” pool.
Full reference: https://api.crossref.org/swagger-ui/index.html
curl https://api.crossref.org/works/10.1038/nature14539{
"status": "ok",
"message-type": "work",
"message-version": "1.0.0",
"message": {
"indexed": {
"date-parts": [
[
2026,
9
]
],
"date-time": "2026-09-23T15:28:19Z",
"timestamp": 1790177299748,
"version": "4.1.0"
},
"reference-count": 103,
"publisher": "Springer Science and Business Media LLC",
"issue": "7553",
"license": [
{
"start": {
"date-time": "2015-05-27T00:00:00Z",
"timestamp": 1432684800000
},
"content-version": "tdm",
"delay-in-days": 0,
"URL": "https://www.springer.com/tdm"
},
{
"start": {
"date-time": "2015-05-27T00:00:00Z",
"timestamp": 1432684800000
},
"content-version": "vor",
"delay-in-days": 0,
"URL": "https://www.springer.com/tdm"
}
],
"content-domain": {
"domain": [
"link.springer.com"
],
"crossmark-restriction": false
},
"short-container-title": [
"Nature"
],
"published-print": {
"date-parts": [
[
2015,
5
]
]
},
"DOI": "10.1038/nature14539",
"type": "journal-article",
"created": {
"date-parts": [
[
2015,
5
]
],
"date-time": "2015-05-26T12:10:15Z",
"timestamp": 1432642215000
},
"page": "436-444",
"update-policy": "https://doi.org/10.1007/springer_crossmark_policy",
"source": "Crossref",
"is-referenced-by-count": 76857
}
}select keeps the response small.
curl "https://api.crossref.org/works?query=attention+is+all+you+need&rows=2&select=DOI,title,author,is-referenced-by-count"{
"status": "ok",
"message-type": "work-list",
"message-version": "1.0.0",
"message": {
"facets": {},
"total-results": 1385257,
"items": [
{
"DOI": "10.1007/978-3-031-84300-6_13",
"title": [
"Is Attention All You Need?"
],
"author": [],
"is-referenced-by-count": 55
},
{
"DOI": "10.2139/ssrn.4993784",
"title": [
"Attention Is All You Need: An Analysis Of The Valuation Of Artificial Intelligence Tokens"
],
"author": [],
"is-referenced-by-count": 0
}
],
"items-per-page": 2,
"query": {
"start-index": 0,
"search-terms": "attention is all you need"
}
}
}