Unpaywall API
Free REST API providing open access status and full-text links for 120M+ scholarly articles. Look up any article by DOI to get its OA status, best open access location (publisher or repository), license, version, and all available free copies. Also supports title-based search across the full database. No API key required — just include your email address in requests. Rate limit: 100,000 calls per day.
Documentation
Specifications
Schemas & Data
Other Resources
SpectralRules
https://raw.githubusercontent.com/api-evangelist/unpaywall/refs/heads/main/rules/unpaywall-rules.yml
NaftikoCapability
https://raw.githubusercontent.com/api-evangelist/unpaywall/refs/heads/main/capabilities/open-access-discovery.yaml
OpenAPI
#Open Access
#DOI
#Scholarly Articles
#Search