MoonkaleFrom Prompt19 (2026-09-20). Two Obsidian plugins and two conventions Daniel relies on, plus the rule he set: JavaScript for these is permitted as an extension for the desktop editor when there is no Rust engine — the one sanctioned exception beyond the three editor bundles (JavaScript Inventory). Formulas via KaTeX already work (013).
| feature | in Obsidian | markdown syntax | how in Moonkale | engine |
|---|---|---|---|---|
| Typst math | Wypst renders $…$ / $$…$$ with Typst instead of MathJax/KaTeX | the same $…$ — the content is Typst math (integral_0^1 x^2 dif x = 1/3) rather than LaTeX | a setting per folder, .moonkale/markdown.json → "math": "katex" | "typst" (default katex): with typst, the rich editor’s math nodes are rendered by the typst crate that is already compiled in for the Typst preview — each formula becomes an SVG (typst compiles $…$ inside a minimal page, typst-svg renders), cached by content hash; Quartz already renders Typst math for the site via @myriaddreamin/rehype-typst, so the vault reads the same both places | Rust, exists; the wiring is a Milkdown node view that asks Rust for an SVG instead of calling KaTeX (onMath(id, source) → mathResult(id, svg)) |
| TikZ diagrams | Inline TikZ / TikZJax renders ```tikz fences with TeX compiled to wasm in the page | ```tikz code fence (a full \begin{tikzpicture}… body; optional \usepackage lines) | a desktop-only extension tikz (opt-in) with two backends behind one trait, chosen by what is installed: (1) native TeX — tectonic or pdflatex + dvisvgm/pdftocairo on PATH, tikz fence → SVG, cached; (2) TikZJax — the wasm TeX engine + its JS glue as a packages/js/tikzjax bundle (≈ 10 MB with the TeX memory dump; loaded on first use, never in the web build). Rust rewrite: none exists — a TeX engine in Rust is not on anyone’s roadmap; CeTZ (Typst’s TikZ analogue) is the Typst-native way to draw, and a ```cetz fence rendered by the compiled-in typst crate is the Rust path for new diagrams, offered next to tikz | JS or an external binary, desktop only; never on web or mobile |
| Mermaid | built in (also in Quartz: this vault uses it) | ```mermaid fence | a packages/js/mermaid bundle behind the same code-fence renderer trait (FenceRenderer { languages, render(source) → svg/html }), loaded lazily; no Rust Mermaid exists (the diagram layout engines are the hard part). Platform: desktop and web (it is plain JS, 2.5 MB, so lazy and opt-in on the phone) | JS |
| Tabs | an Obsidian plugin renders ```tabs blocks (tab: Title sections) as a tab strip | ```tabs fence with tab: headers | pure Rust/Dioxus: the fence renderer trait’s first native implementation — a tab strip whose panes are markdown rendered by the rich editor itself; source stays a fence so Quartz/GitHub degrade to a code block (a Quartz plugin later) | Rust |
The one mechanism: code-fence renderers
The rich editor gets a fence renderer contribution (FenceRenderer in ext-api, contributed by extensions): a fence whose language matches is shown as the renderer’s output (SVG/HTML/Dioxus) with click to edit back to the source, exactly like the KaTeX block today. Tabs (Rust), CeTZ and Typst math (Rust via typst), Mermaid and TikZJax (JS bundles, desktop/web as stated) all plug into it; the source editor shows the fence with highlighting. Rendering is asynchronous and cached by content hash under .moonkale/cache/.
Platform and rules
- Rust first where an engine exists: Typst math, CeTZ and tabs never touch JavaScript.
- JS only as an opt-in desktop extension (Daniel’s exception): TikZJax; Mermaid is allowed on web too because it is just JS and Quartz users expect it.
- Never in the core bundle: each is its own lazily loaded asset; the phone gets tabs and Typst math, not TikZ.
- Static/Quartz parity: the markdown stays valid for Quartz (
rehype-typst, Mermaid, code fences); tabs need a small Quartz transformer to look the same on the site.
Order (when scheduled)
- Fence renderer contribution + tabs (proves the mechanism in pure Rust).
- Typst math setting, SVG through the
typstcrate; CeTZ fence with the same path. - Mermaid bundle (JS, lazy).
- TikZ extension: native TeX backend first, TikZJax second.