OpenAlex
Open scholarly graph: 322M works, CC0 data, works/authors/institutions/topics API.
About
OpenAlex (OurResearch nonprofit) is the open scholarly graph: 322M works with authorships, venues, DOIs, open-access links, citation edges, and concepts, assembled from Crossref, PubMed, DataCite, DOAJ, and arXiv. The underlying data is CC0 — including full bulk snapshots.
Pricing change (Feb 2026, verified via multiple sources): the hosted REST API is now usage-metered — $1/day free credit, then per-call rates; single-record DOI/ID lookups remain free. Older guides calling it fully free are stale. For agents: api.openalex.org/works?search=... with filters (from_publication_date, open_access.is_oa, cites:W...), plus a content API for cached PDFs.
What it can do
- 322M works with full metadata graph
- Authors, institutions, topics, funders as first-class entities
- Citation edges and OA PDF locations
- CC0 bulk snapshots
- Polite-pool email convention for reliability
Setup
- Sign up for a free API key at openalex.org (strongly advised; ~10x quota vs anonymous).
- Call
https://api.openalex.org/works?search=...&api_key=.... - Use filters:
from_publication_date,type:article,open_access.is_oa:true,cites:W.... - For bulk needs, download the CC0 snapshot instead of hammering the API.
Prerequisites
Free API key (recommended); HTTP client.
Use cases
Works with
Trust score — 7/10
Scored 7/10 (metrics tier). Nonprofit, fully open CC0 data — the most open entry in this batch — but the Feb 2026 API metering change (verified via multiple sources) means 'free' needs qualification now, and hosted-API terms are still provider-controlled. Core infrastructure with high adoption. Metrics tier per the 8+ rule.
How the trust score is built
Full methodology →- Adoption · stars/downloads, log-scaled vs peers
- 9.0/10
- Maintenance · recency, releases, issue load
- 5.0/10
- Openness · license + docs
- 4.8/10
- Manual review · sanity read + red-flag check
- 9.0/10
- · provider-tier estimate — thinner evidence (no public adoption metric)
- · core open scholarly infra; 322M works; CC0 data — provider-tier estimate
- · no release date — neutral maintenance score
- · manual review: data fully open (CC0); API moved to $1/day free credit Feb 2026 — verified via multiple sources; DOI lookups remain free; license: CC0 data; hosted API usage-priced since Feb 2026 (OurResearch)
Sources
Every fact above was checked against these sources. Where a claim comes from the provider and couldn't be independently verified, the text says so.