scholarly-metadata
OpenAIRE Graph
A European open-science knowledge graph that links hundreds of millions of research products — publications, datasets, software, and funding records. You can query it through its API or browse the Explore portal on the web. It is a good choice for tracing the connections between a paper and its underlying data, software, or grant, though the service is mid-migration to a new graph API in 2026 and its older search endpoints are being phased out.
Why it’s useful & how it works
Explore portal carries reCAPTCHA; the API answers both ways. 2026: migrating to the new JSON Graph API (full-migration call 20 May 2026) — target /graph/, not legacy /search.
What’s inside
Hundreds of millions of research products.
API access
NEW https://api.openaire.eu/graph/ ... ; legacy https://api.openaire.eu/search/publications?doi= <doi>&format=json (deprecating)
Access
Programmatic API access (a key may be required — see the API tag).