5.3 KiB
5.3 KiB
title, task, lineage_type, upstream_source, upstream_sha, imported_at, prompt_class, upstream_changes, author, validated
| title | task | lineage_type | upstream_source | upstream_sha | imported_at | prompt_class | upstream_changes | author | validated |
|---|---|---|---|---|---|---|---|---|---|
| OpenAlex API | import | https://github.com/K-Dense-AI/scientific-agent-skills/blob/9c9bd2e9/skills/paper-lookup/references/openalex.md | 9c9bd2e9 | 2026-06-27 | prompt | accepted | upstream | false |
OpenAlex API
OpenAlex is a comprehensive index of 250M+ scholarly works, authors, institutions, sources, and topics. It's the broadest multidisciplinary database in this skill.
Base URL
https://api.openalex.org
Authentication
- API key recommended (free). Get one at https://openalex.org/settings/api
- Pass as:
?api_key=YOUR_KEY - Legacy polite pool still works: add
[email protected]for better rate limits
Rate Limits
- 100 requests/second max
- Usage-based pricing with $1/day free allowance
- Single entity lookups by ID/DOI are free (unlimited)
- List + filter queries: ~$0.0001 each (~10,000/day free)
- Search queries: ~$0.001 each (~1,000/day free)
Key Endpoints
1. Get a single work
GET /works/{id}
Accepts multiple ID formats:
/works/W2741809807 (OpenAlex ID)
/works/doi:10.7717/peerj.4375 (DOI)
/works/pmid:29456894 (PMID)
/works/https://doi.org/10.7717/peerj.4375 (full DOI URL)
2. Search works
GET /works?search={query}&per_page={n}&page={n}
| Parameter | Default | Description |
|---|---|---|
search |
-- | Full-text search (title, abstract, fulltext). Supports boolean: AND, OR, NOT (uppercase) |
search.exact |
-- | No stemming |
search.semantic |
-- | AI embedding search (beta, 1 req/s, max 50 results) |
filter |
-- | Comma-separated field:value pairs |
sort |
relevance | cited_by_count:desc, publication_date:desc, relevance_score:desc |
per_page |
25 | Results per page (max 100) |
page |
1 | Page number (max page * per_page = 10,000) |
cursor |
-- | Use * for first page of deep pagination |
select |
-- | Comma-separated fields to return |
group_by |
-- | Aggregate by field |
Advanced search: Supports wildcards (machin*), fuzzy (machin~1), proximity ("climate change"~5), boolean grouping.
Example:
https://api.openalex.org/works?search=CRISPR+gene+therapy&filter=from_publication_date:2023-01-01&sort=cited_by_count:desc&per_page=10
3. Filter works
GET /works?filter={filters}
Key filter fields:
| Filter | Example | Description |
|---|---|---|
from_publication_date |
2023-01-01 |
Published after date |
to_publication_date |
2024-12-31 |
Published before date |
publication_year |
2024 |
Exact year |
type |
article |
Work type |
cited_by_count |
>100 |
Citation threshold |
is_oa |
true |
Open access only |
has_abstract |
true |
Has abstract |
authorships.author.id |
A5048491430 |
By author ID |
primary_location.source.id |
S137773608 |
By journal/source |
institutions.country_code |
us |
By country |
concepts.id |
C41008148 |
By concept/topic |
doi |
10.1038/nature12373 |
By DOI |
Operators: >, <, ! (negation), | (OR within filter)
Example:
https://api.openalex.org/works?filter=from_publication_date:2024-01-01,type:article,is_oa:true,cited_by_count:>50
4. Other entities
GET /authors?search={name}
GET /authors/{id}
GET /sources?search={name} (journals, repositories)
GET /sources/{id}
GET /institutions?search={name}
GET /institutions/{id}
GET /topics/{id}
Authors and institutions accept similar filter/sort/pagination parameters.
5. Cursor pagination (for >10,000 results)
GET /works?filter=publication_year:2024&cursor=*&per_page=100
Response includes meta.next_cursor. Pass it as cursor={value} in the next request. Stop when next_cursor is null.
Response Format
Work object (key fields)
{
"id": "https://openalex.org/W2741809807",
"doi": "https://doi.org/10.7717/peerj.4375",
"title": "The state of OA",
"publication_year": 2018,
"publication_date": "2018-02-13",
"type": "article",
"language": "en",
"is_retracted": false,
"cited_by_count": 1169,
"open_access": {
"is_oa": true,
"oa_status": "gold",
"oa_url": "https://doi.org/10.7717/peerj.4375"
},
"authorships": [{
"author": {"id": "https://openalex.org/A5048491430", "display_name": "Heather Piwowar"},
"institutions": [{"display_name": "Impactstory"}]
}],
"primary_location": {
"source": {"display_name": "PeerJ", "issn_l": "2167-8359"}
},
"abstract_inverted_index": {"Despite": [0], "growing": [1], "interest": [2], ...},
"referenced_works": ["https://openalex.org/W123...", ...],
"ids": {"openalex": "...", "doi": "...", "pmid": "..."}
}
Abstract inverted index
Abstracts are stored as {word: [positions]}. To reconstruct:
def reconstruct(inverted_index):
positions = {}
for word, indices in inverted_index.items():
for idx in indices:
positions[idx] = word
return ' '.join(positions[i] for i in sorted(positions.keys()))
List response
{
"meta": {"count": 3771834, "page": 1, "per_page": 10},
"results": [...]
}
Error Format
HTTP 403 for invalid API key, 429 for rate limit exceeded. Error responses include a message field.