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# Zettelclean

Keep a Zettelkasten filename's slug in sync with the note's H1 heading.

Zettelclean resolves the "three sources of truth for a title" problem (filename vs H1 vs
YAML `title:`) by separating concerns:

- The **H1 heading** in the note body is the single source of truth for the human title.
- The **filename** is a derived machine identity: `TIMEID-slug(H1).md`.
- No YAML is written. Files stay pure Markdown.

It is a small, one-way, prefix-gated renamer: edit the H1, and a moment later the filename's
slug tail follows. Nothing else is touched.

## How it works

- A note is a zettel when its filename starts with a recognized **prefix**: a **TIMEID** (a run
  of 12 to 18 digits) always, and a **`yyyy-mm-dd` date** too if you enable date mode in settings.
  The prefix is followed by any non-digit or the end of the name - so `20260728145404-my-note.md`,
  `202607281454.md`, `202607281454 my note.md`, and (date mode) `2026-07-30 Journal.md` all
  qualify. Files without a recognized prefix are ignored, so plain notes, Excalidraw and Kanban
  files are never renamed.
- The prefix is fixed and never changes; only the slug tail is regenerated.
- When you edit the H1, zettelclean waits about 4 seconds of idle, then renames the file to
  `prefix-slug(H1).md` using Obsidian's own rename (so backlinks are updated). A 6 second
  cooldown prevents a just-renamed file from being renamed again.
- Sync is strictly one-way, H1 to filename. Renaming a file by hand is never fought.
- **Sticky tail:** the tail follows the H1 when it produces a slug; with no H1 the existing tail
  is kept and cleaned. The tail is never deleted - delete the H1 and the filename keeps its last
  slug. A note that never had a title stays bare (`TIMEID.md`); one with no usable title (empty
  H1 and no sluggable tail) is left untouched.
- If a rename would collide with an existing filename, zettelclean keeps the current name and
  shows a notice.

The slug is case-preserving, ASCII, dash-separated: accents are folded (`Ciências` becomes
`Ciencias`), runs of punctuation and whitespace collapse to a single dash, and leading and
trailing dashes are trimmed.

## Creating notes

Use Obsidian's built-in **Unique note creator** core plugin to mint the TIMEID:

1. Settings -> Core plugins -> enable "Unique note creator".
2. Set "Unique note format" to `YYYYMMDDHHmmss` (14 digits, second precision - avoids
   same-minute collisions).
3. Click the "Create new unique note" ribbon icon. You get `20260728145404.md`; type your
   `# Title`, and zettelclean takes over from there.

Zettelclean also accepts an existing 12-digit (`YYYYMMDDHHmm`) vault if you prefer not to
change the setting.

### Retrofitting existing notes

Notes created before you adopted this workflow have no TIMEID. Right-click such a note in the
file explorer and choose **"Prefix timestamp to filename"**. It mints a fresh timestamp,
prepends it, and the note is now a zettel that syncs on future H1 edits.

### Date-prefixed notes (journaling)

Turn on **date mode** in settings to also treat `yyyy-mm-dd`-prefixed notes as zettels. A daily
note `2026-07-30.md` gains a slug once you title it (`# Gratitude` -> `2026-07-30-Gratitude.md`),
and `2026-07-30 Morning pages.md` is cleaned to `2026-07-30-Morning-pages.md`.

## Slugging a folder name

Right-click a folder and choose **"Slug folder name"** to ASCII-clean it in place (this folder
only): `Citações` becomes `Citacoes`. The rename goes through Obsidian, so `[[links]]` into the
folder are updated. It aborts if a sibling of that name already exists, and never touches the
vault root.

## Pretty sidebar (optional)

By default the file explorer shows the slugged filename (with dashes). If you want the sidebar,
tabs and graph to show the pretty H1 instead - with no YAML in your files - install the
**Front Matter Title** community plugin and set its feature templates to:

```
#heading | _basename
```

That reads the first H1 directly and falls back to the filename when there is none.

## Settings

One setting: **Recognized filename prefixes** (Settings -> Community plugins -> Zettelclean).

- **Timestamp only** (default) - only 12-18 digit TIMEID prefixes.
- **Timestamp and date** - also `yyyy-mm-dd` prefixes, for journaling.

The 4 second settle and 6 second cooldown are fixed.

## Development

Dependencies are managed with **pnpm** (see "Why pnpm, not npm" below). Node 22+ ships
`corepack`, so you do not need to install pnpm globally, and the `packageManager` field in
`package.json` pins the exact version.

```bash
corepack pnpm install     # first time, or after a dependency change
corepack pnpm run dev     # compile in watch mode
corepack pnpm run build   # typecheck and produce main.js
corepack pnpm test        # run the slug unit tests (Node's built-in runner)
corepack pnpm run lint    # eslint with the Obsidian ruleset
```

The pure string logic lives in `src/slug.ts` and is unit-tested in isolation; the Obsidian
wiring lives in `src/main.ts`. Tests run on Node's built-in test runner (`node --test`) - there
is no vitest or jest dependency.

### Why pnpm, not npm

**Do not run `npm install` or `npm ci` in this repo.** This project is developed on a **ZFS**
filesystem, and npm's installer renames many directories in parallel (to hoist and dedupe
packages). That races ZFS's directory-metadata handling and aborts with:

```
npm error code ENOTEMPTY
npm error syscall rename
```

pnpm avoids the problem entirely: it hard-links packages from a global content-addressable
store instead of renaming directories into place, so it installs cleanly on the same disk.

Notes for contributors:

- Only `npm install` / `npm ci` are affected. Running *scripts* through npm (`npm run build`)
  still works, because that just spawns tsc/esbuild and installs nothing. Still, prefer `pnpm`
  everywhere for consistency.
- The lockfile is `pnpm-lock.yaml` (committed). There is no `package-lock.json`; do not create
  one.

## License

GNU General Public License v3.0 or later (`GPL-3.0-or-later`).
Copyright (C) 2026 Ruben Carlo Benante (Dr. Béco) <rcb@beco.cc>.
See [LICENSE](LICENSE) for the full text.