CORE API

CORE aggregates open access research from 15,000+ repositories worldwide. It provides full text for 37M+ articles and metadata for 368M+ papers.

Base URL

https://api.core.ac.uk/v3

Important: GET search paths require a trailing slash (e.g., /v3/search/works/ not /v3/search/works).

Authentication

Header: Authorization: Bearer YOUR_API_KEY
Query param: ?api_key=YOUR_API_KEY
Register at: https://core.ac.uk/services/api

Without auth: Basic metadata queries work, but full text is NOT available (returns "Not available for public API users").

Rate Limits (token-based)

User Type	Daily Tokens	Per-Minute Max
Unauthenticated	100/day	10/min
Registered Personal	1,000/day	25/min
Registered Academic	5,000/day	10/min

Simple queries cost 1 token. Downloads and scroll pagination cost 3-5 tokens.

Key Endpoints

1. Search works

GET /v3/search/works/?q={query}&limit={n}&offset={n}

Parameter	Default	Description
`q`	required	Search query (supports field lookups, boolean operators)
`limit`	10	Results per page (max 100)
`offset`	0	Pagination offset
`scroll`	false	Enable scroll pagination for >10,000 results
`sort`	relevance	`relevance` or `recency`

POST alternative (for complex queries):

POST /v3/search/works
Content-Type: application/json

{"q": "machine learning", "limit": 10, "offset": 0}

Example:

https://api.core.ac.uk/v3/search/works/?q=CRISPR+gene+therapy&limit=10

2. Query language

Operator	Example	Description
AND	`title:"AI" AND authors:"Smith"`	Both conditions
OR	`title:"AI" OR fullText:"Deep Learning"`	Either condition
Grouping	`(title:"AI" OR title:"ML") AND yearPublished>"2020"`	Precedence
Field lookup	`title:"Machine Learning"`	Search specific field
Range	`yearPublished>2018`	Numeric comparison
Exists	`_exists_:fullText`	Field must exist
Phrase	`title:"Attention is all you need"`	Exact phrase

Searchable fields: abstract, arxivId, authors, contributors, createdDate, dataProviders, depositedDate, documentType, doi, fullText, id, language, license, oai, title, yearPublished

3. Get work by ID

GET /v3/works/{id}

id is a CORE Work ID (integer). Example: /v3/works/267312

4. Get output by ID

GET /v3/outputs/{id}

5. Download full text

GET /v3/outputs/{id}/download

Returns binary PDF. Requires authentication.

GET /v3/works/tei/{id}

Returns TEI XML format.

6. Search outputs

GET /v3/search/outputs/?q={query}&limit={n}&offset={n}

Search by DOI: q=doi:10.1038/nature12373

Response Format

Search response

json

{
  "totalHits": 2281337,
  "limit": 10,
  "offset": 0,
  "scrollId": null,
  "results": [...]
}

Work object (key fields)

json

{
  "id": 8848131,
  "title": "Attention Is All You Need",
  "authors": [{"name": "Ashish Vaswani"}, ...],
  "abstract": "The dominant sequence...",
  "doi": "10.48550/arXiv.1706.03762",
  "arxivId": "1706.03762",
  "yearPublished": 2017,
  "downloadUrl": "https://core.ac.uk/download/...",
  "fullText": "Full text content (when authenticated)...",
  "language": {"code": "en", "name": "English"},
  "documentType": "research",
  "citationCount": 145678,
  "dataProviders": [{"name": "arXiv"}],
  "links": [{"type": "download", "url": "..."}]
}

Pagination

Standard: offset + limit (max 10,000 results)
Scroll: Set scroll=true. Response includes scrollId. Use in subsequent requests to page beyond 10,000 (costs more tokens).

Error Handling

Under heavy load, the API may return partial shard failure messages. These are transient -- retry after a brief wait.