node package manager


Serve Markdown documents as static content (middleware)


Serves Markdown documents as static content. Acts as middleware for Connect (Express) and Union (Flatiron).

Use this to serve a folder full of Markdown documents (and its sub-folders) as though they were static content.


npm install docserver


  • Handles Github-Flavored Markdown, using the marked package.
  • Per-directory template support.
  • In-memory caching that can easily be replaced by a custom cache module (e.g., Redis)
  • Can handle requests for an entire site, or just one subdirectory of a site.
  • Command-line utility serves the current directory for quick and easy local documentation browsing.


See Connect, Union, plain, and Redis examples in the examples and bin subdirectories.

Using Express

var express = require('express')
  , docserver = require('docserver')
var app = express();
  dir: __dirname + '/docs',  // serve Markdown files in the docs directory... 
  url: '/'}                  // ...and serve them at the root of the site 
console.log(docserver.version + ' listening on port 3000');

Mapping of URLs to Markdown files

Place Markdown files with the extensions .md or .mdown in your docs directory. (You can override these file extensions; see below for details.) Organize the directory any way you like, with any number of subdirectories.

Each directory can have an (or index.mdown) file that will be served if the user requests the directory name.

Template support

A template.html file, if present in the same directory as a Markdown document, will be used to format that document. You can have multiple templates: docserver will search parent directories up the directory tree to find the nearest template.html and use that.

This allows you to have a default template, and override with custom templates in each subdirectory.

Template syntax

{{{ title }}}

In template.html, the text {{{ title }}} will be replaced by the current document’s title. The title is guessed by taking the contents of the first non-empty HTML tag from the rendered HTML. In other words, since most people usually start their Markdown documents with an <h1> tag, that tag’s contents become the title.

{{{ markdown }}}

In template.html, the text {{{ markdown }}} will be replaced by the HTML that was rendered from the Markdown document.

Example template

  <meta charset="utf-8">
  <title>{{{ title }}}</title>
{{{ markdown }}}

Directory structure example

For this example, assume the following directory structure:

├── template.html
└── api/
    ├── template.html
    └── v1.0/

Example URLs

Given the “Using Express” example code and the directory structure shown above, a request for http://localhost:3000/ would return docs/ (converted to HTML, of course).

File extensions are handled automatically. In this example, the README file can be requested as http://localhost:3000/README or http://localhost:3000/

Likewise, the api/ file can be requested as http://localhost:3000/api/, http://localhost:3000/api/, or even http://localhost:3000/api/index.

Example Templates

The file docs/ is served using the template file docs/template.html.

The file docs/api/ would be served using the template file docs/api/template.html.

The file docs/api/v1.0/ is in a directory that does not have a template file. In this case, docserver will search up the directory tree until it finds a template. This file would be served using the template file docs/api/template.html.

(If docserver can find no template for a document, it will be served as a bare-bones HTML file.)



Returns the docserver middleware, which is compatible with Connect, Express, Union and Flatiron.

Options when creating an instance of the docserver middleware


The directory where your Markdown documents are located.

example: { dir: __dirname + '/docs' }


The URL from which your documents should be served.

example (docserver handles the root level of the web site): { url: '/' }

example (docsever handles URLs under /docs): { url: '/docs/' }


Markdown files with these extensons will be served.

example: {extensions: ['.markdown', '.md']}

Defaults to ['.md', '.mdown']


Files with these extensions will be served as-is. This allows you to place non-Markdown files, such as CSS, images, and other assets, side-by-side with your Markdown documents.

example: {passthrough: ['.css', '.js', '.png', '.txt']}

Defaults to ['.css', '.png', '.jpg', '.jpeg', '.js']


Add additional HTTP headers to the output.

example: {headers: {'Cache-Control': 'public,max-age=3600'}}


Override the caching subsystem. The default uses an in-memory cache.

To disable caching, set this to false. (You must use false. “Falsy” values like 0 or undefined will not work.)

No other subsystems are provided, but there is an example using Redis in the examples subdirectory.

example: {cache: YourCacheClass}


If true, docserver will watch your documents dir for changes. If any files are added, removed, or changed, the cache will be flushed.

This means you do not have to restart the server if you change any of your documents or templates.

This feature is experimental and off by default.

example: {watch: true}

Defaults to false

Error documents

When an HTTP error occurs, docserver will look for a document matching the error number, using the same logic that is used to find templates. Currently only 404 errors are supported this way.

For example, to have a custom 404 error page, create a file. It will be converted to HTML and served using template.html just like any other Markdown file would be.

Like templates, you can have custom error documents in each subdirectory and docserver will use the nearest one when serving an error.


Q: How do I add a Cache-Control header?

Use the headers option:

var middleware = docserver({
    headers: {'Cache-Control': 'public,max-age=3600'},
    // other options…

Q: I updated one of my Markdown documents, but docserver is still showing the old version.

The old version of the document is cached, either by docserver or by your web browser.

If you used a Cache-Control header, the document may be cached by your web browser. Hit F5 (or Cmd-R, or Ctrl-R) a couple of times to refresh.

If you still see the old document, then it’s been cached by docserver. Your options are:

  • restart docserver
  • or, disable server-side caching by passing false as the cache option
  • or, use the experimental watch option so that docserver will automatically notice any changes

Q: How does the cache work?

docserver aggressively caches the rendered, HTML form of your documents.

The first time a document is requested, docserver has to read it from disk (along with any template) and render it to HTML. On subsequent requests for the same document, it will be served from cache, which should be extremely fast.

In addition, requests that result in a 404 error are cached, so once docserver searches for a document and doesn’t find it, it won’t waste time looking for that document again.

By default, once a document is cached, docserver will never re-read that document; the cached version will always be served until you reload the server.

You also have the option to disable caching by passing false as the cache option.

If you enable the experimental watch option, the cache is emptied every time a change is detected in your docs directory or any of its subdirectories. Because it may be resource-intensive, this option is turned off by default. Enabling it when you have a large set of documents or subdirectories may exhaust available file handles. If you only have a few documents or subdirectories, feel free to try it out. Contributions to improve this feature are welcome.

Q: How does the CLI (command-line interface) work?

To serve the current directory, just type docserver. (This assumes you had installed docserver globally by passing the -g option to npm install.)

The CLI takes two arguments, the local filesystem directory to serve, and the port number on which to listen:

docserver [dir] [port]

The command-line interface is not intended as a production web server. Rather, it’s a quick way to read local folders containing documentation.