# Europe PMC on Onekey

> 5 endpoints for Europe PMC (5 stable, 0 beta), 1 to 5 credits 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/europepmc
Reference (Markdown): https://onekey.dev/docs/api/europepmc.md
All docs: https://onekey.dev/llms.txt

## Canonical fields returned

Unified-schema fields (same names on every platform), with how many of the 5 mapped Europe PMC endpoints return each:

- `author.displayName` (string): 5
- `content.id` (string): 5
- `content.title` (string): 5
- `content.year` (integer): 5
- `engagement.citations` (integer): 3
- `paper.doi` (string): 3
- `paper.journal` (string): 3
- `content.text` (string): 1
- plus 1 platform-specific field under `ext.`

## Endpoints

### europepmc.article

Europe PMC article (PubMed record) with abstract.
- Price: 1 credit per fresh call. Status: stable. Returns: one record.
- Request: `GET https://api.onekey.dev/v1/europepmc/article?pmid=33087721` with header `x-api-key: YOUR_API_KEY`
- Parameters:
  - `pmid` (string, required): PubMed id (PMID)
- Fields returned: `content.id`, `content.title`, `content.text`, `author.displayName`, `paper.journal`, `content.year`, `paper.doi`, `engagement.citations`
- Reference: https://onekey.dev/docs/api/europepmc/article.md

### europepmc.citations

Europe PMC articles citing a PMID.
- Price: 5 credits per fresh call. Status: stable. Returns: a list.
- Request: `GET https://api.onekey.dev/v1/europepmc/citations?pmid=33087721` with header `x-api-key: YOUR_API_KEY`
- Parameters:
  - `pmid` (string, required): PubMed id (PMID)
- Fields returned: `content.id`, `content.title`, `author.displayName`, `content.year`, `ext.source`
- Reference: https://onekey.dev/docs/api/europepmc/citations.md

### europepmc.references

Europe PMC references of a PMID.
- Price: 5 credits per fresh call. Status: stable. Returns: a list.
- Request: `GET https://api.onekey.dev/v1/europepmc/references?pmid=33087721` with header `x-api-key: YOUR_API_KEY`
- Parameters:
  - `pmid` (string, required): PubMed id (PMID)
- Fields returned: `content.id`, `content.title`, `author.displayName`, `content.year`
- Reference: https://onekey.dev/docs/api/europepmc/references.md

### europepmc.search

Search Europe PMC publications.
- Price: 5 credits per fresh call. Status: stable. Returns: a list.
- Request: `GET https://api.onekey.dev/v1/europepmc/search?q=crispr` with header `x-api-key: YOUR_API_KEY`
- Parameters:
  - `q` (string, required): Search query
- Fields returned: `content.id`, `content.title`, `author.displayName`, `paper.journal`, `content.year`, `paper.doi`, `engagement.citations`
- Reference: https://onekey.dev/docs/api/europepmc/search.md

### europepmc.search_open_access

Search Europe PMC open-access full-text articles.
- Price: 5 credits per fresh call. Status: stable. Returns: a list.
- Request: `GET https://api.onekey.dev/v1/europepmc/search_open_access?q=crispr` with header `x-api-key: YOUR_API_KEY`
- Parameters:
  - `q` (string, required): Search query
- Fields returned: `content.id`, `content.title`, `author.displayName`, `paper.journal`, `content.year`, `paper.doi`, `engagement.citations`
- Reference: https://onekey.dev/docs/api/europepmc/search_open_access.md

## Sample request

```bash
curl "https://api.onekey.dev/v1/europepmc/article?pmid=33087721" \
  -H "x-api-key: YOUR_API_KEY"
```