# Unpaywall on Onekey

> 1 endpoint for Unpaywall (1 stable, 0 beta), 1 credit each. Category: Science & research. One key, one JSON shape.

Base URL: https://api.onekey.dev
Auth: header `x-api-key: <key>`. Call shape: `GET /v1/{platform}/{endpoint}?{params}`.
Every response is `{success, data, metadata, error}`; check `success` first. Cost is in `metadata.credits_charged`. Free when served from cache (0.2 credit for a cached response over 100 KB). Failed and not-found calls are refunded.
Status: stable = verified against the live source; beta = not yet verified, fields may be missing.

Page: https://onekey.dev/platforms/unpaywall
Reference (Markdown): https://onekey.dev/docs/api/unpaywall.md
All docs: https://onekey.dev/llms.txt

## Canonical fields returned

Unified-schema fields (same names on every platform), with how many of the 1 mapped Unpaywall endpoints return each:

- `content.title` (string): 1
- `content.year` (integer): 1
- `paper.doi` (string): 1
- `paper.openAccess` (boolean): 1
- `paper.openAccessUrl` (URL): 1
- `paper.publisher` (string): 1
- plus 1 platform-specific field under `ext.`

## Endpoints

### unpaywall.doi

Open-access status and best free full-text location of a DOI (Unpaywall).
- Price: 1 credit per fresh call. Status: stable. Returns: one record.
- Request: `GET https://api.onekey.dev/v1/unpaywall/doi?doi=10.1038%2Fnature12373` with header `x-api-key: YOUR_API_KEY`
- Parameters:
  - `doi` (string, required): DOI, e.g. 10.1038/nature12373
  - `email` (string, optional, default contact@weft.dev): Contact email required by Unpaywall
- Fields returned: `paper.doi`, `content.title`, `content.year`, `paper.openAccess`, `paper.openAccessUrl`, `paper.publisher`, `ext.openAccessStatus`
- Reference: https://onekey.dev/docs/api/unpaywall/doi.md

## Sample request

```bash
curl "https://api.onekey.dev/v1/unpaywall/doi?doi=10.1038%2Fnature12373" \
  -H "x-api-key: YOUR_API_KEY"
```