Crossref
Scholarly works for Worldwide. Access: Public API. Terms checked November 2, 2026.
Access and terms
| Slug | crossref |
|---|---|
| Records | Scholarly works |
| Places | Worldwide |
| Years | Not stated by the source |
| Access | Public API |
| Key | Not needed. |
| Rate limit | Public pool: rate 5, concurrency 1. Polite pool (a mailto parameter or contact in the User-Agent): rate 10, concurrency 3. The API answers with x-rate-limit-limit and x-rate-limit-interval headers (3 per 1 s on the polite pool when checked). |
| robots.txt | Not checked. |
| Homepage | www.crossref.org/ |
| API docs | www.crossref.org/documentation/retrieve-metadata/rest-api/ |
| Terms | www.crossref.org/documentation/retrieve-metadata/rest-api/access-and-authentication/ |
| Checked by hand | November 2, 2026 |
Notes
DOI metadata for journal articles, books and dissertations, with author affiliations where the publisher deposited them. No key. Lineage joins the polite pool by sending mailto (LINEAGE_CONTACT_EMAIL) as a parameter and in the User-Agent, spaces calls 400 ms apart per instance, caches responses 6 hours as the tips page asks, and backs off on 429. Crossref treats bibliographic metadata as facts with no reuse restriction; abstracts can carry the publisher's copyright, so Lineage does not request them. api.crossref.org serves no robots.txt (404).
Evidence read on November 2, 2026
Status: Live
Live at the last check, 2026-11-03 04:33 UTC. HTTP 200 in 36 ms. One check a day.
JSON: /v1/sources/crossref. For agents: /sources/crossref/llms.txt.