FullVahti — Zotero plugin free · open source Local processing, external metadata lookup
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 explicitly as missing, with a one-click link to find them through your library.
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:found, retraction:not-found, or
retraction:check-needed, catching mass retractions that PubMed alone can miss.
Not-found means no retraction record was returned by the queried sources at the time of
the check, not that the item is proven not retracted.
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
- Download the latest
.xpifrom the GitHub releases page. - In Zotero: Tools → Plugins, click the gear ⚙️, then
Install Plugin From File… and choose the
.xpi. - On first run, enter an optional contact email — it may be included in requests to the open metadata services where their guidance recommends it (e.g. Unpaywall, Crossref, NCBI).
- Optional: set a tag for batch processing, and your library's OpenURL resolver, in Settings.
Compatible Zotero versions are listed on the current GitHub release. Updates automatically once installed.
Privacy
Bibliographic identifiers are sent to the named metadata services. When a PDF is retrieved, your computer connects to the repository or publisher hosting that file. Vahtian does not receive the identifiers, files, or usage data. No accounts, no analytics, no Vahtian server. An optional contact email may be included in API requests where service guidance recommends it. 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.
Common questions
Is FullVahti a Zotero plugin?
Yes. FullVahti installs into Zotero and finds open-access full-text PDFs for your references using Unpaywall and PubMed Central, attaching them to your own library.
Does FullVahti bypass paywalls?
No. FullVahti only retrieves copies that are already open access; it never circumvents a paywall or a publisher's access controls.
What does FullVahti cost, and what does it send?
It is free and local-first, with no accounts, no analytics, and no Vahtian server. Lookups query the public Unpaywall and PubMed Central services directly.