LaTeX macro preamble

Obsidian plugin: define global LaTeX macros for MathJax (inline $…$ and display $$…$$ math in notes). Macros are stored in settings and applied when MathJax loads, similar to a small preamble with \newcommand.

Plugin id: latex-macros-preamble (folder name under .obsidian/plugins/ must match).

What it does

• Adds a Settings → LaTeX macros tab: list of macros, each with a command name (no leading \) and a definition.
• Arity is inferred from placeholders #1, #2, … in the definition; the plugin emits \newcommand{\name}[n]{…} for MathJax.
• Live preview in settings uses Obsidian’s renderMath / finishRenderMath so previews match note rendering.
• Legacy data: if your vault had an older preamble string in plugin data, lines that look like \newcommand / \renewcommand are parsed into the macro list on load.

Using macros in notes

After saving settings, use your commands inside normal math:

$\Class{x : \phi(x)}$

If math does not pick up changes, reload Obsidian (or restart the app) so MathJax is re-initialized with the new preamble.

Limitations

• Only what MathJax supports applies; this is not a full LaTeX engine or PDF export preamble.
• Macros are global to the vault for this plugin’s registered MathJax usage, not per-note files.

Installing from source

If you are not using Community Plugins: in this directory run npm install and npm run build, then copy main.js, styles.css, and manifest.json into .obsidian/plugins/latex-macros-preamble/. For day-to-day development, npm run dev watches and rebuilds main.js.

API (other plugins)

LatexMacrosPlugin implements LatexMacrosPluginApi (src/plugin-api.ts): settings, saveSettings(), applyPreamble(), and previewMacroInElement() for embedding previews.

Further reading

• Obsidian plugin API