I Built 10 Open Source Toolkits for Academic APIs — Here's What I Learned

Over the past month, I built Python toolkits for 10 different academic APIs. Combined, they give you access to 800M+ research papers, 17M researcher profiles, and 30M free PDFs . All free. All open source. Most require no API key. Here's what surprised me along the way. The 10 Toolkits # Toolkit Records API Key? Best For 1 OpenAlex 250M+ papers No Bibliometrics, citations 2 Crossref 150M+ articles No DOI metadata 3 Semantic Scholar 200M+ papers Optional AI summaries 4 CORE 300M+ papers Free key Full text 5 PubMed 36M+ papers No Medical research 6 arXiv 2M+ preprints No AI/Physics/Math 7 Unpaywall 30M+ OA links Email only Free PDFs 8 ORCID 17M+ profiles No Researcher lookup 9 YouTube Innertube Unlimited No Video data 10 Research CLI 800M+ combined No Unified search 5 Things I Learned 1. Academic data is surprisingly free I expected paywalls everywhere. Instead, I found that most major academic databases have free, well-documented APIs . The paywall is on the papers themselves, not the m