Fulltext Retrieval Skill

Batch download open-access full-text PDFs from a DOI list using legitimate OA APIs only. Paywalled articles fail by design and are listed in manual_needed.txt for institutional access or ILL; never work around a paywall or publisher access control.

Pipeline

DOI → arXiv (10.48550/arXiv.* DOIs) → Unpaywall → PMC (Europe PMC / OA FTP / web) → OpenAlex → Crossref → landing page

Each DOI goes through these sources in order until a valid PDF (≥10 KB, %PDF- header) is found. arXiv DOIs (10.48550/arXiv.2401.01234, version suffixes, old-style hep-th/9901001, or a bare arXiv: id) resolve directly to the arXiv PDF first.

Run