# Crossref API > Search scholarly literature and look up rich publication metadata from Crossref, the DOI registry behind millions of journal articles, books, chapters, conference papers and datasets. Full-text search across 150+ million works with relevance or citation sorting and optional filters, retrieve any work by its DOI (plain, doi: or URL form accepted), and search journals and publishers. Every work comes back as a clean record with title, authors and ORCIDs, journal/container, publisher, publication date, volume/issue/page, ISSN/ISBN, abstract, subjects, license and citation count. Authoritative open scholarly metadata delivered through a fast, reliable API — ideal for reference managers, repositories, research analytics, discovery tools and academic apps. ## Authentication All requests require your oanor API key in the `x-oanor-key` header. Get one at https://www.oanor.com/developer/keys. ```bash curl -H "x-oanor-key: oanor_live_…" "https://api.oanor.com/crossref-api/..." ``` ## Pricing - **Free** (Free) — 1,000 calls/Mo, 1 req/s - **Basic** ($7/Mo) — 50,000 calls/Mo, 5 req/s - **Pro** ($19/Mo) — 300,000 calls/Mo, 15 req/s - **Mega** ($59/Mo) — 2,000,000 calls/Mo, 40 req/s ## Endpoints ### Crossref #### `GET /v1/journals` — Search journals **Parameters:** - `query` (query, required, string) — Journal name Example: `nature` - `rows` (query, optional, string) — 1-50 (default 10) Example: `10` **Example:** ```bash curl -H "x-oanor-key: $KEY" \ "https://api.oanor.com/crossref-api/v1/journals?query=nature&rows=10" ``` **Response:** ```json { "data": { "count": 10, "items": [ { "issn": [], "title": "NatureJobs", "subjects": [], "publisher": "Springer Science and Business Media LLC", "total_dois": 0, "current_dois": 0 }, { "issn": [ "0028-0887", "1504-3118" ], "title": "Naturen", "subjects": [], "publisher": "Scandinavian University Press", "total_dois": 1064, "current_dois": 100 }, { "issn": [ "1240-1307", "1765-2979" ], "title": "Natures Sciences Sociétés", "subjects": [], "publisher": "EDP Sciences", "total_dois": 2813, "current_dois": 112 }, { "issn": [ "1982-4513", "1982-4513", "0103-1570" ], "title": "Sociedade & Natureza", "subjects": [], "publisher": "PPUFU - Portal de Periódicos da Universidade Federal de Uberlândia", "total_dois": 1416, "current_dois": 149 }, { "issn": [ "1679- …(truncated, see openapi.json for full schema) ``` #### `GET /v1/members` — Search publishers / members **Parameters:** - `query` (query, required, string) — Publisher name Example: `elsevier` - `rows` (query, optional, string) — 1-50 (default 10) Example: `10` **Example:** ```bash curl -H "x-oanor-key: $KEY" \ "https://api.oanor.com/crossref-api/v1/members?query=elsevier&rows=10" ``` **Response:** ```json { "data": { "count": 2, "items": [ { "id": 78, "names": [ "Elsevier BV", "Elsevier - Biophysical Society", "American Dental Association", "Elsevier - Ambulatory Pediatric Associates", "Elsevier - Institution of Chemical Engineers", "Elsevier - Academic Press", "Social Science Electronic Publishing", "Elsevier - Colegio Nacional de Opticos-Optometristas de Espana", "Canadian Opthalmological Society", "Elsevier - American Society for Experimental Neurotherapeutics", "Elsevier - Wilderness Medical Society", "Elsevier- Spektrum Akademischer Verlag", "Elsevier - Medicine Publishing Company", "Elsevier - Central Mining Institute", "Elsevier - Mosby", "Journal of Bioresources and Bioproducts", "Elsevier (Society for Range Management)", "Elsevier - American Society for Investigative Pathology", "Elsevier - International Federation of Automatic Control (IFAC)", "Elsevier - CIG Media Group LP", "Elsevier - Ediciones Doyma", "Woodhead Publishing", "Elsevier", …(truncated, see openapi.json for full schema) ``` #### `GET /v1/search` — Search scholarly works **Parameters:** - `query` (query, required, string) — Search terms Example: `machine learning` - `rows` (query, optional, string) — 1-50 (default 10) Example: `10` - `offset` (query, optional, string) — Pagination offset (0-10000) Example: `0` - `sort` (query, optional, string) — relevance | published | is-referenced-by-count | updated Example: `relevance` - `filter` (query, optional, string) — Crossref filter (e.g. type:journal-article,from-pub-date:2020-01-01) **Example:** ```bash curl -H "x-oanor-key: $KEY" \ "https://api.oanor.com/crossref-api/v1/search?query=machine+learning&rows=10&offset=0&sort=relevance" ``` **Response:** ```json { "data": { "count": 10, "items": [ { "doi": "10.1093/oso/9780198828044.003.0003", "url": "https://doi.org/10.1093/oso/9780198828044.003.0003", "isbn": [ "9780198828044", "9780191883873" ], "issn": [], "page": "38-65", "type": "book-chapter", "issue": null, "title": "Machine learning with sklearn", "issued": "2019-11-28", "volume": null, "authors": [ { "name": "Thomas P. Trappenberg", "given": "Thomas P.", "orcid": null, "family": "Trappenberg", "sequence": "first", "affiliation": [] } ], "license": [], "abstract": "This chapter’s goal is to show how to apply machine learning algorithms in a general setting using some classic methods. In particular, it demonstrates how to apply three important machine learning algorithms, a support vector classifier (SVC), a random forest classifier (RFC), and a multilayer perceptron (MLP). While many of the methods studied later go beyond these now classic methods, this does not mean that these methods are obsolete. Also, the algorithms discussed here p …(truncated, see openapi.json for full schema) ``` #### `GET /v1/work` — Work by DOI **Parameters:** - `doi` (query, required, string) — DOI (plain, doi: or URL form) Example: `10.1038/nphys1170` **Example:** ```bash curl -H "x-oanor-key: $KEY" \ "https://api.oanor.com/crossref-api/v1/work?doi=10.1038%2Fnphys1170" ``` **Response:** ```json { "data": { "doi": "10.1038/nphys1170", "url": "https://doi.org/10.1038/nphys1170", "isbn": [], "issn": [ "1745-2473", "1745-2481" ], "page": "11-12", "type": "journal-article", "issue": "1", "title": "Measured measurement", "issued": "2009-01", "volume": "5", "authors": [ { "name": "Markus Aspelmeyer", "given": "Markus", "orcid": null, "family": "Aspelmeyer", "sequence": "first", "affiliation": [] } ], "license": [ "http://www.springer.com/tdm" ], "abstract": null, "language": "en", "subjects": [], "subtitle": null, "published": "2009-01", "publisher": "Springer Science and Business Media LLC", "container_title": "Nature Physics", "references_count": 10, "short_container_title": "Nature Phys", "is_referenced_by_count": 9 }, "meta": { "timestamp": "2026-05-30T18:17:14.806Z", "request_id": "5b358505-dc9a-43c7-aebd-88f6d3ca4fa5" }, "status": "ok", "message": "Work retrieved", "success": true } ``` --- Marketplace page: https://www.oanor.com/api/crossref-api OpenAPI spec: https://www.oanor.com/api/crossref-api/openapi.json