Crossref Metadata Search

Overview

The Crossref REST API is the registry of DOI metadata for scholarly works — 150M+ records with titles, authors, abstracts, references, licenses, and funding info. Keyless and free (verified live), it’s the canonical way to resolve and search academic DOIs.

Quick Start

Resolve a DOI (verified live):

curl "https://api.crossref.org/works/10.1103/PhysRevLett.116.061102"

{
  "message": {
    "DOI": "10.1103/PhysRevLett.116.061102",
    "title": ["Observation of gravitational waves from a binary black hole merger"],
    "author": [{ "family": "Abbott", "given": "B. P." }],
    "published-print": { "date-parts": [[2016, 2, 11]] },
    "container-title": ["Physical Review Letters"]
  }
}

Search works:

curl "https://api.crossref.org/works?query=gravitational+waves&rows=5"

Filter by type/date:

curl "https://api.crossref.org/works?query.bibliographic=transformers&filter=type:journal-article,from-pub-date:2025-01-01&rows=5"

Authentication

None — keyless (add mailto= in the query to be a “polite” client).

Rate Limits & Notes

• Free; the polite pool (with mailto=you@example.com) is treated better.
• works/{doi} resolves metadata; /works?query= searches.
• Rich fields: author, title, container-title (journal), abstract, reference (citation list), license, funding, URL.
• Bulk harvesting via /works?filter=from-pub-date:...&cursor=* (cursor pagination).

FAQ

Is Crossref free? Yes — free and keyless (add mailto= for better service).

What’s a DOI? A persistent identifier for a scholarly work — Crossref is its registration agency.

Can I get citations from a paper? Yes — the reference array contains the cited works’ DOIs.