Automatically format markdown files, sync external docs/src code & make better docs
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Latest commit 004e4b6 Jul 16, 2018

Markdown Magic npm-version

Add a little magic to your markdown


Markdown magic uses comment blocks in markdown files to automatically sync or transform its contents.

  • Automatically keep markdown files up to date from local or remote code sources
  • Transform markdown content with custom transform functions
  • Render markdown with any template engine
  • Automatically generate a table of contents
  • ... etc

The comments markdown magic uses are hidden in markdown and when viewed as HTML.

This is generated with markdown-magic view the raw file to see how.

Video demoExample Repo

Table of Contents

Click to expand


npm install markdown-magic --save-dev


import path from 'path'
import markdownMagic from 'markdown-magic'

const markdownPath = path.join(__dirname, '')


markdownMagic(filePath, config, callback)
  • filePaths - String or Array - Path or glob pattern. Uses globby patterns
  • config - See configuration options below
  • callback - callback to run after markdown updates

Configuration Options

  • transforms - object - (optional) Custom commands to transform block contents, see transforms & custom transforms sections below.

  • outputDir - string - (optional) Change output path of new content. Default behavior is replacing the original file

  • matchWord - string - (optional) Comment pattern to look for & replace inner contents. Default AUTO-GENERATED-CONTENT

  • DEBUG - Boolean - (optional) set debug flag to true to inspect the process

CLI Usage

You can use markdown-magic as a CLI command. Run markdown --help to see all available CLI options

markdown --help
# or

This is useful for adding the package quickly to your package.json npm scripts

CLI usage example with options

md-magic --path '**/*.md' --config ./config.file.js

In NPM scripts, npm run docs would run the markdown magic and parse all the .md files in the directory.

"scripts": {
  "docs": "md-magic --path '**/*.md' --ignore 'node_modules'"

If you have a markdown.config.js file where markdown-magic is invoked, it will automatically use that as the configuration unless otherwise specified by --config flag.

/* CLI markdown.config.js file example */
module.exports = {
  transforms: {
    /* Match <!-- AUTO-GENERATED-CONTENT:START (LOLZ) --> */
    LOLZ(content, options) {
      return `This section was generated by the cli config markdown.config.js file`
  callback: function () {


Markdown Magic comes with a couple of built in transforms for you to use or you can extend it with your own transforms. See 'Custom Transforms' below.


Get code from file or URL and put in markdown


  • src: The relative path to the code to pull in, or the URL where the raw code lives
  • syntax (optional): Syntax will be inferred by fileType if not specified
  • header (optional): Will add header comment to code snippet. Useful for pointing to relative source directory or adding live doc links


<!-- AUTO-GENERATED-CONTENT:START (CODE:src=./relative/path/to/code.js) -->
This content will be dynamically replaced with code from the file



Get any remote Data and put in markdown


  • url: The URL of the remote content to pull in


This content will be dynamically replace from the remote url



Generate table of contents from markdown file


  • firsth1 - boolean - (optional): Show first h1 of doc in table of contents. Default false
  • collapse - boolean - (optional): Collapse the table of contents in a detail accordian. Default false
  • collapseText - string - (optional): Text the toc accordian summary
  • excludeText - string - (optional): Text to exclude in the table of contents. Default Table of Contents


toc will be generated here


🔌 Third Party Plugins

Adding Custom Transforms

Markdown Magic is extendable via plugins.

Plugins allow developers to add new transforms to the config.transforms object. This allows for things like using different rendering engines, custom formatting, or any other logic you might want.

Plugins run in order of registration.

The below code is used to generate this markdown file via the plugin system.

const fs = require('fs')
const path = require('path')
const execSync = require('child_process').execSync
const markdownMagic = require('../index') // 'markdown-magic'

const config = {
  matchWord: 'MD-MAGIC-EXAMPLE', // default matchWord is AUTO-GENERATED-CONTENT
  transforms: {
    /* Match <!-- AUTO-GENERATED-CONTENT:START (customTransform:optionOne=hi&optionOne=DUDE) --> */
    customTransform(content, options) {
      console.log('original content in comment block', content)
      console.log('options defined on transform', options)
      // options = { optionOne: hi, optionOne: DUDE}
      return `This will replace all the contents of inside the comment ${options.optionOne}`
    /* Match <!-- AUTO-GENERATED-CONTENT:START (RENDERDOCS:path=../file.js) --> */
    RENDERDOCS(content, options) {
      const fileContents = fs.readFileSync(options.path, 'utf8')
      const docBlocs = require('dox').parseComments(fileContents, { raw: true, skipSingleStar: true })
      let updatedContent = ''
      docBlocs.forEach((data) => {
        updatedContent += `${data.description.full}\n\n`
      return updatedContent.replace(/^\s+|\s+$/g, '')
    /* Match <!-- AUTO-GENERATED-CONTENT:START (pluginExample) --> */
    pluginExample: require('./plugin-example')({ addNewLine: true }),
    /* Plugins from npm */
    // count: require('markdown-magic-wordcount'),
    // github: require('markdown-magic-github-contributors')

/* This example callback automatically updates and commits the changes */
const callback = function autoGitCommit(err, output) {
  // output is array of file information
  output.forEach(function(data) {
    const mdPath = data.outputFilePath
    if(!mdPath) return false
    const gitAdd = execSync(`git add ${mdPath}`, {}, (error) => {
      if (error) console.warn(error)
      const msg = `${mdPath} automatically updated by markdown-magic`
      const gitCommitCommand = `git commit -m '${msg}' --no-verify`
      execSync(gitCommitCommand, {}, (err) => {
        if (err) console.warn(err)
        console.log('git commit automatically ran. Push up your changes!')

const markdownPath = path.join(__dirname, '..', '')
markdownMagic(markdownPath, config, callback)

Plugin Example

Plugins must return a transform function with the following signature.

return function myCustomTransform (content, options)
/* Custom Transform Plugin example */
const merge = require('deepmerge')
module.exports = function customPlugin(pluginOptions) {
  // set plugin defaults
  const defaultOptions = {
    addNewLine: false
  const userOptions = pluginOptions || {}
  const pluginConfig = merge(defaultOptions, userOptions)
  // return the transform function
  return function myCustomTransform (content, options) {
    const newLine = (pluginConfig.addNewLine) ? '\n' : ''
    const updatedContent = content + newLine
    return updatedContent

View the raw file file and run npm run docs to see this plugin run

This content is altered by the pluginExample plugin registered in examples/generate-readme.js

Other usage examples

Custom Transform Demo

View the raw source of this file to see the comment block and see how the customTransform function in examples/generate-readme.js works

This will replace all the contents of inside the comment DUDE

Prior Art

This was inspired by Kent C Dodds and jfmengels's all contributors cli project.

This section was generated by the cli config markdown.config.js file


MIT © DavidWells