Using LaTeX Snippets in Markdown Files in Neovim

Published on 2025-09-24.

I frequently write notes in Markdown using Neovim, and many of those notes contain math. Unfortunately, all of my handy LaTeX snippets created with LuaSnip don’t work in Markdown, which makes it a pain to write anything beyond the simplest equations. In this post, I document how I got my snippets working in Markdown.

Basic Setup

The first step is to tell LuaSnip to load LaTeX snippets in Markdown files. This saves us from having to duplicate all our LaTeX snippets. Since I use lazy.nvim as my package manager, I just had to tweak the config function like this:

config = function()
  local ls = require("luasnip")

  ls.config.set_config({
    ...
  })

  -- Make TeX snippets available in markdown
  ls.filetype_extend("markdown", { "tex" })

  ...
end,

It turns out that this is all we need to get basic snippet functionality working. However, many of my snippets use conditional expansion, with snippets only expanding if the cursor is inside a math environment. For example, typing ff automatically expands to \frac{}{} when I’m inside dollar signs or an align environment, but it won’t expand when I type ‘affirm’ or ‘puff’ in normal text. Since a lot of my go-to snippets rely on this, that’s the next thing I set up.

Conditional Expansion in Math Environments

When I write LaTeX files, I rely on a package called VimTex for syntax highlighting and a bunch of other useful features. One of its perks is that it can detect math environments, which we can use as a condition for snippet expansion with the following Lua function (see the article by ejmastnak for more details):

tex_utils.in_math = function()
  -- This function requires the VimTeX plugin.
  return vim.fn["vimtex#syntax#in_mathzone"]() == 1
end

But VimTeX is a filetype-specific plugin, so it only loads for .tex files. To get the same functionality in Markdown, we need to create a nvim/after/syntax/markdown.vim file with the following contents:

" From https://github.com/lervag/vimtex/issues/2395
if exists('b:current_syntax')
  unlet b:current_syntax
endif

syn include @tex syntax/tex.vim
syn region markdownMath start="\\\@<!\$" end="\$" skip="\\\$" contains=@tex keepend
syn region markdownMath start="\\\@<!\$\$" end="\$\$" skip="\\\$" contains=@tex keepend

let b:current_syntax = 'markdown'

This snippet first clears any existing Markdown syntax settings, then tells Neovim to pull in LaTeX syntax rules from syntax/tex.vim (provided by VimTeX). It defines $...$ and $$...$$ as math environments, so anything inside them gets highlighted and treated like LaTeX math, even in a Markdown file.

Bonus for VimWiki Users

If you use VimWiki for note-taking and also rely on the <Tab> key for snippet expansion, you’ll need to free up <Tab> in insert mode, since VimWiki already uses it for shortcuts. I solved this by adding the following autocommand for VimWiki:

config = function()
  vim.api.nvim_create_autocmd("FileType", {
    pattern = "vimwiki",
    callback = function()
      -- Disable <Tab> in insert mode.
      vim.keymap.del("i", "<Tab>", { buffer = true })
    end,
  })
end,

Conclusion

That’s it, we’re all set! We’re now ready to give Giles Castel a run for his money in Markdown ;). That said, this setup is not perfect. The biggest limitation is that it only recognizes math environments defined with single or double dollar signs, so conditional snippets won’t work inside environments like align. This is not a huge deal for me though, since all serious math gets done in .tex files. If you’re curious, you can check out my full Neovim configuration here.