Zotero + Obsidian + Claude Code

Package:

Demo12_zotero_obsidian_claude.zip · 550 KB · 30–40 minutes

What actually breaks

Seven notes in vault/papers/, written between November 2025 and August 2026. Nine items in the library. Every note was correct the day it was written.

Since then: the library was corrected, a duplicate was typed in by hand, an attachment was replaced with the published version, and a PDF appeared in storage/ that no item claims. None of the notes know any of this.

The one field holding the two systems together:

zotero_key: 4J8KQW2M

Eight characters, stable, and the only thing in either system that is. Not the title, which gets retyped. Not the cite key, which Better BibTeX regenerates whenever you fix metadata. Not the filename, which carries a year that may turn out to be wrong.

In this workspace, two of the seven notes have a zotero_key that resolves.

The five ways they came apart

• A dead key. Points at nothing. The paper is in the library under a different key, matchable by DOI. The easy one.
• No key at all. Written before the convention existed. Shows up from the other side as “this library item has no note” — one problem, two symptoms, and an agent checking one direction reports it twice.
• The wrong record of the right paper. The key resolves, so a naive check passes it — but it resolves to a hand-typed duplicate with the same DOI, the wrong year and no attachment. linker should refuse to fix this silently: two items share one DOI, and quietly picking one buries a library problem you needed to see.
• Stale metadata that already left the building. A note says 2024 / bioRxiv; the library says the same; the attached PDF says 2025, Methods in Protein Science, different DOI. The library’s own Extra field admits it: "replaced attachment with published version." Three artefacts now carry the wrong year — the frontmatter, the filename, and a line reading "cited in the group slides as Lindqvist 2024 preprint."
• Two notes, one paper, opposite conclusions. March: 23% improvement, from the abstract. July: 7.5%, from the table, plus "my earlier note on this paper is wrong." They point at different keys, so the join does not reveal they are the same paper. The Zotero duplicate has propagated into the vault, and the vault no longer knows it is contradicting itself.

Two owners, one folder

Both Edit and Write are denied on zotero/ and on vault/topics/. The first protects the system of record; the second protects your own thinking. Bash(mv:./zotero/**) is denied too — one plausible “tidy up” and every attachment path stops resolving.

And linker may change one field: zotero_key. Not the prose, not the claims, not the years — even the ones that are wrong. Those belong to drift, which has no Write tool at all.

The note you cannot cite

One note holds the strongest evidence in the workspace — the ThermoNet-2 authors’ own supplement, reporting 8.0 °C on the 43 held-out records whose sequences were not in training, against the 4.9 in their abstract. Its source sits in zotero/storage/ and belongs to no library item.

So it will never appear in a bibliography, a citation manager, or a reference list. The note says so itself: “This is the most important number I have and I cannot cite it.”

The fix is not a vault fix. It is: open Zotero, add the file, give it metadata. An agent that offers to add it to the library is about to write to a denied path, and should say instead that this one is yours to do.

Where this sits

Same literature across all three, so this one spends its time on the connection rather than re-teaching the papers.

Nothing here was anyone’s mistake. Metadata got corrected, a duplicate got typed in, an attachment got replaced, a file got dropped in a folder. Every note was right when it was written. The drift is simply what ordinary use does to two systems with no shared identifier — which is why the one line that matters in this whole package is zotero_key:.

Using it on your own work

From Zotero: select a collection → right-click → Export Collection → Better BibTeX with Export Files ticked, and again as CSV. Drop both next to your vault, copy CLAUDE.md and .claude/ across, add zotero_key to your note template, and start filling it in.

That one field is the entire integration, and it is worth more than any MCP server you could install — because it survives a Zotero update, a vault rename, a change of reference manager, and a laptop.