Vahtian

FullVahti — Zotero plugin free · open source

Find the open-access PDF, before you give up on it.

FullVahti finds freely available full-text PDFs for your Zotero references — in two clicks, with a tidy report of what's still missing.

It never bypasses a paywall. Paywalled papers are reported honestly as missing, with a one-click link to find them through your library.

Download the latest .xpi View on GitHub

What it does

Point FullVahti at a set of references — by tag or by selection — and it looks for an open-access copy of each one, attaches it, and records the licence. Every item is labelled so you can see at a glance what was found, what's missing, and what needs a human look:

fulltext:pdf-found fulltext:pdf-missing fulltext:check-needed

The missing list is the point as much as the found list: you get an honest account of the gaps, not a false sense that everything is in hand.

How it finds PDFs

FullVahti queries two well-known open-access services by DOI or PMID:

Unpaywall

The open-access index across institutional and subject repositories.

PubMed Central

The PMC Open Access Subset, via NCBI's official channels.

It never bypasses a paywall. FullVahti only retrieves copies the publisher or author has made openly available. Anything behind a paywall is reported as missing — with an OpenURL "find in my library" link so you can reach it through your institution's legitimate access.

More than retrieval

Retraction flags

Cross-checks each item against PubMed and Crossref / Retraction Watch, tagging retraction:retracted, retraction:none, or retraction:check-needed — catching mass retractions that PubMed alone can miss.

Citation metadata check

A read-only comparison against the Crossref record. It surfaces missing fields and mismatches as citation:incomplete / citation:mismatch — it never auto-edits your data.

Library access

OpenURL resolver support: for anything not openly available, a one-click "find in my library" link routes you to your institution's holdings.

CiteVahti hand-off (advanced)

An optional, token-guarded write-back to your local Zotero, with a preview → confirm → audit → undo flow and allow-listed tag prefixes only. No silent writes.

Install

  1. Download the latest .xpi from the GitHub releases page.
  2. In Zotero: Tools → Plugins, click the gear ⚙️, then Install Plugin From File… and choose the .xpi.
  3. On first run, enter your email — it's sent only to the open services that ask for it (Unpaywall, NCBI, Crossref), never to PDF hosts.
  4. Optional: set a tag for batch processing, and your library's OpenURL resolver, in Settings.

Requires Zotero 7–9. Updates automatically once installed.

Privacy

Nothing leaves your machine except the DOI / PMID lookups to the open services named above. No accounts, no analytics, no Vahtian server. Your contact email is shared only with the APIs that require it, and never with PDF sources. The work stays in your Zotero.

Open source

FullVahti is Apache-2.0, plain JavaScript with no build step, © Heidi Helena Andersén / Vahtian. Read the code, file an issue, or build the .xpi yourself on GitHub. See how to cite it if it helped your work.