remark-math-inline

A remark plugin for clean, unambiguous inline math syntax using :math[...].

Why?

The standard $...$ syntax has issues:

• Ambiguity — conflicts with currency notation
• Fragile parsing — single $ delimiters are hard to parse reliably
• Tooling issues — many Markdown parsers struggle with $

This plugin provides :math[E = mc^2] as a cleaner alternative.

Install

npm install remark-math-inline

Usage

import { unified } from 'unified'
import remarkParse from 'remark-parse'
import remarkMathInline from 'remark-math-inline'
import remarkRehype from 'remark-rehype'
import rehypeKatex from 'rehype-katex'
import rehypeStringify from 'rehype-stringify'

const html = await unified()
  .use(remarkParse)
  .use(remarkMathInline)
  .use(remarkRehype)
  .use(rehypeKatex)
  .use(rehypeStringify)
  .process('The formula :math[E = mc^2] shows mass-energy equivalence.')

Syntax

Inline math: :math[E = mc^2]

Euler's identity: :math[e^{i\pi} + 1 = 0]

Nested brackets work: :math[f(x) = [a, b]]

Escaping

Only brackets and backslashes can be escaped — all other backslashes pass through unchanged for LaTeX compatibility:

• \[ → literal [ (does not increment bracket depth)
• \] → literal ] (does not close)
• \\ → literal \

Example: \alpha stays as \alpha, \frac{1}{2} stays as \frac{1}{2}

Boundary Rules

• :math[ must NOT be preceded by a word character (a-z, A-Z, 0-9, _)
• Cannot span multiple lines

foo:math[x]     <!-- Does NOT parse -->
test(:math[x])  <!-- Parses -->
test :math[x]   <!-- Parses -->

Block Math

For block/display math, use fenced code blocks:

```math
\int_0^1 x^2 dx = \frac{1}{3}
```

This already works with rehype-katex — no additional plugin needed.

Packages

This monorepo contains:

Package	Purpose
micromark-extension-math-inline	Tokenizer
mdast-util-math-inline	AST utilities
remark-math-inline	Remark plugin

For direct micromark or mdast integration, see the individual package READMEs.

Adjacency

:math[...] cannot be preceded by a word character. Use parentheses for adjacency:

mass(:math[m])     <!-- Works -->
mass:math[m]       <!-- Does NOT parse -->

With remark-directive

If using both plugins, the one registered last wins for :math[...] syntax:

// Math wins:
unified()
  .use(remarkDirective)
  .use(remarkMathInline)  // registered last

// Directive wins:
unified()
  .use(remarkMathInline)
  .use(remarkDirective)   // registered last

License

MIT