What you get#
Onekey exposes Unpaywall as 1 endpoint behind one API key: 1 endpoint return one record (data is an object). 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 Unpaywall also works for the rest of the science & research category.
Endpoints#
| Endpoint | What it does | Parameters | Credits | Status |
|---|---|---|---|---|
doi | Open-access status and best free full-text location of a DOI (Unpaywall). | doi*, email | 1 | 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 unpaywall.doi (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/unpaywall/doi?doi=10.1038%2Fnature12373" \
-H "x-api-key: YOUR_API_KEY"Fields you get back#
These unified fields come back from Unpaywall, with the same names as on every other platform. The count is how many of its 1 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 |
|---|---|---|
content.title | string | 1 |
content.year | integer | 1 |
paper.doi | string | 1 |
paper.openAccess | boolean | 1 |
paper.openAccessUrl | URL | 1 |
paper.publisher | string | 1 |
The full schema is in Unified schema.
Pricing#
Every Unpaywall endpoint costs 1 credit per call. 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.