Plugins

Updated Nov 12, 2026

Every article compiles through textlane, a Rust Markdown pipeline that also runs JavaScript plugins. The plugins option adds your own plugins to it, in two slots:

• md runs on the Markdown tree (mdast), where remark-style plugins work
• html runs on the HTML tree (hast), where rehype-style plugins work

import { defineConfig } from "livemark"
import * as html from "textlane/html"
import { remarkHello } from "./plugins/remark-hello.ts"

export default defineConfig({
  plugins: {
    md: [remarkHello],
    html: [html.externalLinks({ target: "_blank" })],
  },
})

What a plugin can be

Each slot is a list that takes the same entries as textlane's use:

• A JavaScript plugin: a unified-style attacher, a function that returns a transformer, which changes the tree in place or returns a new one. Most remark and rehype transform plugins fit here.
• A native plugin: one of the plugins textlane/md and textlane/html export, such as html.externalLinks() or md.shiftHeading(). It runs in Rust, so it's faster than a JavaScript plugin.
• A plugin with options: a [plugin, options] pair.

A JavaScript plugin transforms a tree that's already been parsed. It can't add new syntax, a parser or a compiler. For new block syntax, use a directive and handle it in an md plugin.

Where each slot runs

parse → GFM, math, directives, MDX → md plugins → heading ids, components, path rewrites
→ HTML → syntax highlighting, KaTeX → html plugins → heading slugs, table of contents → MDX

• md plugins run before Livemark renders directives as components, so they see every directive. A directive name Livemark doesn't know reaches them intact. Left alone, it renders as its source text.
• html plugins run after syntax highlighting and before heading slugs and the table of contents, so a heading a plugin adds gets an anchor and appears in the "On this page" outline.

Writing one

This md plugin replaces a ::hello directive with a paragraph:

import type { Root } from "mdast"

export function remarkHello() {
  return (tree: Root) => {
    tree.children = tree.children.map(node =>
      node.type === "leafDirective" && node.name === "hello"
        ? { type: "paragraph", children: [{ type: "text", value: "Hello!" }] }
        : node,
    )
  }
}

Install @types/mdast or @types/hast for the tree types, and import mdast-util-directive once, as import type {} from "mdast-util-directive", to type directive nodes.

Rebuilds

Editing the config, or any local file it imports, such as plugins/remark-hello.ts, restarts the dev server and recompiles every article. A plugin installed from npm is cached with your articles, so after upgrading it, delete .livemark/.cache/ to recompile.