What you get#
Onekey exposes Crossref as 10 endpoints behind one API key: 5 endpoints return one record (data is an object) and 5 endpoints return a list (data is an array). Every answer uses the same envelope (success, data, metadata, error), the cost is reported in metadata.credits_charged, and fields are mapped onto the unified schema so the code you write for Crossref also works for the rest of the science & research category.
Endpoints#
| Endpoint | What it does | Parameters | Credits | Status |
|---|---|---|---|---|
funder | Crossref funder by funder id. | id* | 1 | stable |
funders_search | Search Crossref funders. | q* | 5 | stable |
journal | Crossref journal by ISSN. | issn* | 1 | stable |
journals_search | Search Crossref journals. | q* | 5 | stable |
member | Crossref member by member id. | id* | 1 | stable |
members_search | Search Crossref members (publishers). | q* | 5 | stable |
prefix | Crossref DOI prefix owner. | prefix* | 1 | stable |
types | Crossref work types. | - | 5 | stable |
work | Crossref work by DOI. | doi* | 1 | stable |
works_search | Search Crossref scholarly works. | q* | 5 | stable |
A * marks a required parameter. Each endpoint name links to its reference page with the full parameter table, caching window and a recorded response.
Make a request#
This calls crossref.funder (1 credit, stable). Replace YOUR_API_KEY with your key; sign up, no card. 1,000 free credits cover the open-platform endpoints. Hard-to-reach platforms (X, TikTok, Instagram, Reddit, and others marked on their page) need a verified email and a purchased pack.
curl "https://api.onekey.dev/v1/crossref/funder?id=100000001" \
-H "x-api-key: YOUR_API_KEY"Fields you get back#
These unified fields come back from Crossref, with the same names as on every other platform. The count is how many of its 10 mapped endpoints return the field; a field the source lacks is null, never missing. 1 platform-specific field (ext.<name>) come on top, documented on each endpoint page.
| Field | Type | Endpoints |
|---|---|---|
entity.name | string | 7 |
entity.id | string | 5 |
entity.location | string | 4 |
paper.publisher | string | 4 |
content.id | string | 3 |
content.title | string | 3 |
author.displayName | string | 2 |
content.type | string | 2 |
content.url | URL | 2 |
content.year | integer | 2 |
engagement.citations | integer | 2 |
paper.issn | string | 2 |
paper.journal | string | 2 |
The full schema is in Unified schema.
Pricing#
Crossref calls cost 1 to 5 credits, flat per endpoint. Free when served from cache (0.2 credit for a cached response over 100 KB). Invalid, failed or not-found calls are not charged. See pricing for credit packs.