📐 Auto Math for Obsidian

✍️ Write equations at the speed of thought — automatic LaTeX snippet expansion for Obsidian.

Auto Math automatically expands LaTeX-style math snippets while you type in Obsidian.
It's like a mini LaTeX auto-completion engine — lightweight, fast, and entirely local.

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✨ Features

• 🔹 Instant snippet expansion – type \frac, \sqrt, \sum, etc., and get ready-to-edit templates.

• 🔹 Smart Limits – optional context‑aware behaviour for ∫ and ∑:

  • $…$ → compact form (\int_{}^{}, \sum_{}^{})
  • $$…$$ → display form with limits (\int\limits_{}^{}, \sum\limits_{}^{})

• 🔹 Multiline templates – environments like \align expand across multiple lines with proper formatting.

• 🔹 Custom rule file – all expansions are stored in .obsidian/plugins/auto-math/rules.json (user-editable).

• 🔹 Live reload – changes in the rules file are applied immediately, no restart required.

• 🔹 Built-in math pack – includes 38 essential LaTeX commands.

• 🔹 Custom Rules Editor – edit triggers and expansions directly inside Obsidian settings.

• 🔹 Toggle anytime – quickly enable or disable with the ribbon icon or command palette.

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🧮 Default Rule Pack

Auto Math v0.2.1 comes preloaded with 38 essential triggers:

Basic Commands

Trigger	Expands to
\frac	\frac{}{}
\dfrac	\dfrac{}{}
\tfrac	\tfrac{}{}
\cfrac	\cfrac{}{}
\binom	\binom{}{}
\dbinom	\dbinom{}{}
\tbinom	\tbinom{}{}
\text	\text{}
\sqrt	\sqrt{}
\root	\sqrt[]{}
\pow	{}^{}
\abs	\left|{}\right|
\norm	\left\|{}\right\|
\vec	\vec{}
\hat	\hat{}
\bar	\bar{}
\overline	\overline{}
\underline	\underline{}
^^	^{}
__	_{}

Sums, Integrals & Limits

Trigger	Expands to
\sum	\sum_{}^{}
\int	\int_{}^{}
\lim_	\lim_{}
\limsup	\limsup_{}
\liminf	\liminf_{}
\max	\max_{}
\min	\min_{}
\inf	\inf_{}
\sup	\sup_{}

Logarithms

Trigger	Expands to
\log	\log_{}

LaTeX Environments

Trigger	Expands to	Use case
\align	\begin{align}...\end{align}	Aligned equations (with numbering)
\aligned	\begin{aligned}...\end{aligned}	Aligned equations (no numbering)
\gather	\begin{gather}...\end{gather}	Centred equations
\cases	\begin{cases}...\end{cases}	Piecewise functions
\array	\begin{array}{}...\end{array}	Custom arrays
\matrix	\begin{matrix}...\end{matrix}	Matrix (no brackets)
\pmatrix	\begin{pmatrix}...\end{pmatrix}	Matrix with ( )
\bmatrix	\begin{bmatrix}...\end{bmatrix}	Matrix with [ ]
\split	\begin{split}...\end{split}	Split equations

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⚙️ Installation

Manual

1. Download the latest release from the Releases page.

2. Extract the folder auto-math into your vault under:

   .obsidian/plugins/auto-math/
   

3. Enable Auto Math in Settings → Community Plugins → Installed plugins.

4. That's it — start typing \frac, \sqrt, \sum and watch them expand automatically!

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🧰 Configuration

Open Settings → Auto Math to customise:

• Enabled – toggle Auto Math on/off.

• Rules file path – defaults to .obsidian/plugins/auto-math/auto-math.rules.json.

• Smart Limits – context‑aware expansions for ∫ and ∑.

• Reload / Create / Open – reload or open your external rules file.

• Debug logs – show extra information in the developer console.

• Custom Rules Editor – view, add, delete, and edit your rules interactively.

• Save rules to file – writes changes to the JSON file immediately.

• Reset to default math pack – restores the built-in default rule set.

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📐 Multiline Maths Mode

Auto Math now supports Smart Limits in multiline $$...$$ blocks.

Example:

$$
\int x dx  ← expands to \int\limits_{}^{}
$$

The plugin automatically scans neighbouring lines (up to 50 by default) to detect display maths context.

Technical note: The scan depth can be adjusted by modifying maxScanLines in the plugin settings file (default: 50 lines). This is stored in .obsidian/plugins/auto-math/data.json.

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LaTeX Environments

Auto Math includes snippets for common LaTeX environments. These automatically expand into multiline blocks with proper formatting.

Example Usage

Input:

$$
\align
$$

Expands to:

$$
\begin{align}
| ← cursor here
\end{align}
$$

Then you can write your equations with \\ for line breaks:

$$
\begin{align}
x + y &= 5 \\
x &= 5 - y
\end{align}
$$

Result: $$ \begin{align} x + y &= 5 \ x &= 5 - y \end{align} $$

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💡 Customisation Example

If you'd like to add your own expansions, open auto-math.rules.json and add entries like:

[
  { "trigger": "\\ceil", "expand": "\\left\\lceil{}\\right\\rceil" },
  { "trigger": "\\floor", "expand": "\\left\\lfloor{}\\right\\rfloor" },
  { "trigger": "\\bmatrix", "expand": "\\begin{bmatrix}\n & \\\\\n\\end{bmatrix}" }
]

Then click Reload rules now — your new triggers will be active instantly.

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🪶 Notes

• The plugin works fully offline and doesn't require any external dependencies.

• Uses plain JSON and Obsidian's own vault API.

• Safe to edit while running — changes are detected automatically.

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🧑‍💻 Credits

Released under the MIT licence.