4.2.0 • Public • Published



npm install umberto

Building documentation of a single project

Note: The only documentation type supported at the moment is JSDoc.

Step 1: Create the umberto.json configuration file in the project's root directory or in the docs directory. This file will tell Umberto how to build documentation for this project.

You can also have a look at CKEditor5 as a reference.

Example 1: umberto.json

  "name": "CKEditor 5",
  "slug": "ckeditor5",
  "path": "docs",
  "startPage": "builds/guides/whats-new.html",
  "redirects": {
    "old-url": "new-url",
    "builds/guides/license-and-legal.html": "builds/guides/support/license-and-legal.html"
  "googletagmanager": {
    "domains": [ "" ],
    "gtm": "GTM-XXXXXX"
  "googleanalytics": {
    "domains": [ "" ],
    "config": { "trackingId": "U-XXX-Y" }
  "feedbackWidget": {
	  "domains": [ "" ],
	  "apiKey": "XXXXX"
  "extraStyles": "assets/styles.css",
  "groups": [
      "name": "API",
      "id": "api-reference",
      "sourceDir": "api",
      "slug": "api",
      "type": "jsdoc"
      "name": "Builds",
      "id": "builds",
      "slug": "builds",
      "categories": [
          "name": "Guides",
          "id": "builds-guides",
          "slug": "guides",
          "categories": [
              "name": "Integration",
              "id": "builds-integration",
              "slug": "integration",
              "order": 100
              "name": "Development",
              "id": "builds-development",
              "slug": "development",
              "order": 200
  "items": [
      "path": "packages/ckeditor5-autoformat",
      "prefix": "autoformat"
  "github": {
    "url": "url/to/github/repo"
  "scripts": {
    "snippet-adapter": "relative/path/to/snippetadapter",
    "precondition": "gulp docs:api"
  "sitemap": {
    "hostname": "",
    "excluded": [ "builds/guides/migrate.html" ],
    "extraUrlSettings": [
        "url": "api/module_core_editor_editor-Editor.html",
        "priority": 0.8
  "canonicalUrlBeginning": "",
  "variables": {
    "VARIABLE_NAME": "value"
Property Description
name Project name.
slug Project slug to avoid name collisions.
path Path where to look for documentation source files (Markdown files, images etc.). The path is relative to the location of umberto.json.
startPage Path to page linked in drop down menu. If there is nothing provided, then index.html (from main project directory) is used.
redirects Object where as a key is stored string representing old-url and as a value is stored string representing new-url. (Currently redirects are used only in deployment scripts of big-bang docs.)
googleoptimize domains - Array of whitelisted domains from which GO can be used; id - container ID
googletagmanager domains - Array of whitelisted domains from which GA can be used; gtm - container ID
googleanalytics domains - Array of whitelisted domains from which GA can be used; config - options passed to ga('create') method
feedbackWidget domains - Array of whitelisted domains from which feedback widget can be used; apiKey - unique key for widget
extraStyles Path to extra css relative to path. Accepts a string or an array of strings. Each project can append its own styles that way.
groups A list of top-level groups into which the documentation is split.
[group].name The name of a group.
[group].id Group ID. For API docs it should always be api-reference.
[group].sourceDir Directory inside of path where to look for this group's sources.
[group].slug Human- and machine-readable name for this group to use when constructing URLs.
[group].type For API docs it specifies the documentation tool used to generate docs from source comments.
[group].categories Group's categories.
items Sub-repositories. If not specified, it will be created automatically from packages directory. Source directory name can be changed by assigning a new string or an array of strings for the multiple directories to config.packagesDir, 'packages' is default.
[items].path Path to sub-repository.
[items].prefix Sub-repository prefix.
github.url Url to GitHub repository. Normally it is taken from package.json but can be specified here if needed.
github.issueUrl An option which allows customizing the URL where user will be redirected after clicking the "Report an issue" button. An absolute URL should be provided.
github.contributeUrl An option which allows customizing the URL where user will be redirected after clicking the "Contribute to this guide" button. An absolute URL should be provided.
scripts External scripts and commands used by Umberto.
scripts.snippet-adapter Function which generates live code snippets from {@snippet} tags.
scripts.precondition Command to be executed before generating documentation. For example a gulp task running JSDoc on project's source code.
sitemap Configuration object for sitemap.xml
sitemap.hostname Hostname where documentation will be published.
sitemap.excluded An array of urls to be excluded from the sitemap.
sitemap.extraUrlSettings An array of settings per url. Currently only used to set custom priority per url.
canonicalUrlBeginning String representing beginning of URL address added to canonical in html pages. Will be overwritten if defined in umberto-main.json. Default value:
variables Object contain list of macros which will replace its occurrence in documentation. More details in variables section.

If Google Tag Manager is set then Google Analytics is not generated (as it is usually added into GTM).

Groups and categories can define the order in which the documentation will appear in the side navigation tree.

Make sure that documentation sources (e.g. API docs, JSON data) are stored in directories given by umberto.json.

Sample documentation setup for the example above:

    |---*.json | (any JSON files generated by JSDoc in this case)

Step 2: Run Umberto:

require ( 'umberto' ).buildSingleProject( options )

  • skipApi - skip building API docs,
  • skipValidation - skip links validation,
  • skipLivesSnippets - skip building live code samples,
  • snippetOptions - options object passed to snippetAdapter building live code samples,
  • dev - skip js minification, don't clear build directory when rebuilding docs, reuse unchanged files,
  • clean - clear build directory before generating documentation,
  • verbose - displays more information during generating documentation.
  • createSymLinks - add symbolic links ('latest') to necessary projects in output folder.
  • watch - activate watch mode in Umberto. Markdown files are rebuild and refreshed in destination directory without rebuilding rest of the documentation.
  • validateW3C - activate validation of builded page with The Nu Html Checker.

The documentation will be output to the build/docs directory.

Combined documentation of multiple projects

require ( 'umberto' ).buildMultiProjects( options )

umberto-main.json is required in the root of a combined documentation project.


    "name": "CKEditor Ecosystem",
    "logo": "project-logo.svg",
	"projects": [
	"ignoredProjects": [
	"additionalDocumentation": {
		"projects/ckeditor5": [
		"projects/ckfinder": [
	"commonFilesPath": "common-files/",
	"canonicalUrlBeginning": ""
Property Description
name Project name to be displayed on the home page.
logo Path to the logo image file to be displayed on the home page.
projects An array of paths to documented project directories. These projects should contain umberto.json files and follow conventions of single project scenario.
commonFilesPath Path to a directory containing files common for entire project. Example: robots.txt, which is the home page.
additionalDocumentation Object containing information about additional paths with documentation for given projects.
additionalDocumentation.<Project_Name> Array of paths relative to umberto-main.json where additional documentation for <Project_Name> are stored. <Project_Name> is string used in projects section inside this config.
canonicalUrlBeginning String representing beginning of URL address added to canonical in html pages. Value overwrites definition in umberto.json. Default value:
ignoredProjects String or Array of strings with slugs of projects which links won't be converted during docs generation.
variables Object contain list of macros which will replace its occurrence in documentation. More details in variables section. Variables from umberto-main overwrites variables from project config.

For the example above, project-logo.svg should be located in common files directory.

Using a local version of Umberto

cd umberto
npm link            # Creates a global link.

cd ../
npm link umberto    # link-install the package


Documentation created with umberto provides shortcut Shift+D, which allows on presentation longnames of API entries. Shortcut works as a toggle. Current value is stored in local storage and it is preserved when user moves between documentation pages.

Writing guides


All guides should be written in Markdown and placed in the docs directory of the documented project. Further directory structure does not matter for Umberto, because guides output location is determined by the guide category (see category). However, it is a recommended convention to put guides in a directory structure reflecting the category structure.

File name

Every guide in the same directory or belonging to the same category should have a unique file name.


Every guide should have a front-matter at the top, which looks like this:

category: builds-guides
title: Overview [optional]
slug: overview [optional]
order: 10 [optional]
toc: false [optional]
toc-limit: 5 [optional]
badges: [ premium, ... ] [optional]
sitenav: false [optional]
feedback-widget: false [optional]
menu-title: Overview whatever [optional]
meta-title: <title> tag's exact content [optional]
meta-title-short: <title> tag's content. Automatic suffix will be added (e.g. "- CKEditor 5 Documentation") [optional]
meta-description: <meta name="description"> content [optional]
contributeUrl: [optional] {Boolean/String} If `undefined` or `true` then default URL is generated. If `false` then no URL is generated. Otherwise provided string is used as URL.
issuesUrl: [optional] {Boolean/String} If `undefined` or `true` then default URL is generated. If `false` then no URL is generated. Otherwise provided string is used as URL.
modified_at: [optional] {String} A date that should follow the format: YYYY-MM-DD. Represents the last editing of the guide. Starting from the date, in the project navigation will be displayed the indicator "🆕" over 90 days.


Each guide has to be assigned to a category (category ID). Categories are defined in the umberto.json file of the documented project. Category ID should be used in front-matter.

The category also defines the output location of a guide after processing by Umberto.


A guide named with the following front-matter:

category: builds-guides

in the ckeditor5 project, with this umberto.json file, will be written to <PROJECT_BASE_PATH>/builds/guides/overview.html because the builds-guides category has a slug guides and belongs to the builds category (categories can be nested).

Use category: none for pages not belonging to any category, e.g. 404 page. 404 page should also specify layout: 404 in front matter.

title [optional]

If no <h1> heading is present in a guide, the title will be used to create the guide title automatically. It is recommended to put a <h1> heading in a guide and skip this option.

folded [optional]

If defined and set to true, the category will be folded.

slug [optional]

If slug is defined, the guide's file name after processing by Umberto will be changed to the slug.

order [optional]

Can be set to sort the guides within the same category. If skipped, guides are sorted alphabetically by title.

toc [optional]

If defined and set to false, table of contents will not be rendered.

toc-limit [optional]

If defined and set to 0 or greater integer, the table of contents will be limited to the defined depth (e.g. for value 2, only <h2> and <h3> headings will be shown in the table of contents). Value 0 is an equivalent of using toc: false.

sitenav [optional]

If defined and set to false, there will be no left-side navigation and main content will be centered.

feedback-widget [optional]

If defined and set to false, feedback widget element will not be rendered at the end of page.

menu-title [optional]

Guide title to be displayed on the navigation tree (if it should be different from the original guide's title).

Tags and other features

Tags are strings which can be used in guides and are replaced by Umberto with generated content (e.g. links, code snippets).

Links to API reference


{@link @projectName longname linkText}


{@link @ckeditor5 module:ui/template~Template#render Render method}

Note: If longname doesn't start with module:, please use @linkapi instead of @link.

Example links for CKEditor 4:

{@linkapi CKEDITOR.config Configuration Reference} ->

{@linkapi CKEDITOR.dialog.definition.uiElement UI element definition} ->

{@linkapi CKEDITOR.dialog.definition#resizable resizable} ->


It is optional and must be used only if creating a link to other project's API (in case of a multi-project documentation).


The "path" to an API entity. It must begin with module: followed by the package name, module name and class name with a ~.


Linking to EditorConfig should be done like this:

{@link module:core/editor/editorconfig~EditorConfig Editor Config}

If you want to link to a specific property or method, type its ID after the #:

{@link module:core/editor/editorconfig~EditorConfig#plugins Editor Config}

The text that should appear as a link in the guide.

Note: When linking to package pages, please follow the convention below (Links to guides).


{@link api/ui UI Package Documentation}

Links to Examples in CKEditor4 project


{@linkexample exampleFileName linkText}

The exampleFileName is name of an output file without extension which present sample in CKEditor4 project. File is linked to content of sdk folder.


{@linkexample index CKEditor Example}
{@linkexample fileupload#uploading-dropped-and-pasted-images &#x201C;Uploading Dropped and Pasted Images&#x201D;}

Links to guides


{@link pathToGuide linkText}

The pathToGuide must be the physical path to the guide file from the docs directory.


A link to should be:

{@link builds/guides/overview Builds overview}

In order to link to a guide of another project please follow this syntax:

{@link @projectslug pathToGuide linkText}

where @projectslug is the slug of another project and can be find in the project's umberto.json


{@link @letters index Home page of Letters}

Note: It is possible to link to a guide from a JSDoc comment using {@glink} tag (so that Umberto can distinguish it from a regular JSDoc's {@link} tag):

{@glink @projectSlug finalPathToGuide linkText}

where @projectslug is the slug of another project and can be find in the project's umberto.json. This parameter is optional.

Important: In this case finalPathToGuide must be a guide's final URL. Final URL may be different than guide's physical path (usually it's the same though)


{@glink builds/guides/migrate Migration guide}

Links escaping

Umberto allows on link escaping, when curly brackets are preceed with backslash. There are required 2 backslashes for regular text and single backslash inside code blocks.


  • \\{@link path name\\} will be transformed into {@link path name} in output page.
  • `\{@link path name\}` will be transformed into <code>{@link path name}</code> in output page.

Importing a guide into another guide

It is possible to import a guide into another guide within the same project. This is useful when a guide needs to appear in different categories and user wants to avoid maintaining duplicated content.


{@importguide path/to/guide}


{@importguide builds/guides/overview}


Syntax of the {@img} tag:

{@img pathToImg alt text}

It is possible to specify the image width as well:

{@img pathToImg width alt text}

// Example
{@img assets/img/feature-link.png 503 Simplified link dialog.}

The pathToImg must be a physical path to the image from the docs directory, including the file extension.

The alt text is the alt attribute of the <img> tag.

The width must be an integer that has at least two digits.

Note: Images can be added using standard HTML <img> tags, too:

<img src="%BASE_PATH%/path/to/image.png">

Note: %BASE_PATH% should be typed literally (it will be converted to something like ckeditor5/0.10.0).

The path/to/image.png is the path to the image relative to the docs directory.

Code snippets

Markdown syntax can be used for basic code snippets using the triple backtick (```):

<div class="foo">
<p>Lorem ipsum...</p>

The {@snippet} tag

Live Snippets are pieces of code generated by the Snippet Adapter. Every project provides its own Snippet Adapter to Umberto. CKEditor5 snippets are examples of actual editor so they require building before being inserted into a guide.


{@snippet pathToSnippet}

The pathToSnippet is a path relative to the docs/_snippets directory and ends with the snippet file name without extension.

Note: Every Live Snippet should be placed inside the docs/_snippets directory; it can be nested into more directories. HTML, JS, CSS (and other) files of the same snippet should have the same file name.


ClassicEditor Sample is generated from the following tag:

{@snippet examples/classic-editor}`

If you need to add an image in a snippet, you can use:

<img src="%BASE_PATH%/path/to/image.png">

where path/to/image.png is the path to the image relative to the docs directory.


<info-box type>

Notices can be used to highlight some important information.

Example here:

<info-box hint>
	If you do not want to fork the official build, you can just clone it. However, you will not be able to commit and push your customizations back to [GitHub](

Available box types:

  • info (default)
  • hint
  • warning

Errors documentation

Use {@errors} tag to insert a list of errors into a guide.


By default, Hexo will replace all URLs with HTMLAnchorElement. In other words, if parser finds a URL-like string, it will become to <a href="URL" target="_blank">URL</a>.

In order to disable this option, you need to wrap your text in {% raw %} and {% endraw %} tags.


Default behaviour:
ASP.NET => <a href="http://ASP.NET" target="_blank">ASP.NET</a>
Disable autolinker:
{% raw %}ASP.NET{% endraw %} => ASP.NET

Link validation

If it is needed to have a link, which shouldn't be validated, add data-skip-validation="true" to the link.

Writing Examples for CKEditor4

Umberto can transform html files formerly used in SDK repository, to proper Example page. However there is few important parts which need to be fulfilled to properly convert such document.

Example content

Example content is generated from html element with class sdk-contents. HTML Element with this class can also poses attribute data-cke-preset (e.g data-cke-preset="full"). Such content use CKEditor from CDN resources instead of locally build one.

Meta tags

There are used few metatags, which control how Example is processed by Umberto:

Meta tag name Description
sdk-samples Name of samples present as source codes at the end of page. If there is multiple samples, each title is separate with pipe character.
sdk-category Name of category where belong given example page.
sdk-order Order value, which determine how samples are sorted in navigation tree.

Other tags

Umberto also search for other tags with specific attributes, to properly render Exmpele page.

Name of <tag>/attribute Description
<title> Content of this tag is used as name in navigation tree.
data-sample Attribute added to multiple tags on page. Tags with the same number will be combined as one outputted source code. If given code might exists in multiple samples, then more values might be added after comma, eg ( data-sample="1,2,4" ). Number in data sample is related to position of title in meta tag sdk-samples.
data-sample-short Content of text area is replaced with default short value. Content is defined in umberto.json as shortEditorContent under sdk category.
data-sample-preserve-whitespace Preserves tabulator characters used in source code.
data-sample-strip-outer-tag Removes outer tag when its content is used inside "Get source code" section on example's page.
data-sample-template Name of template which is used to display "Get source code" section. Currently only empty parameter is supported, which prevents of using default template.
data-sample-highlighter Name of syntax highlighter which should be used for given sample (default is used html). You can define other such as js, jsx, etc. List is based on currently supported syntax highlighter in Umberto.
type="template" Content of such tag will be directly added to outputed code. It might be helpful to provide some links or scripts in samples, which you don't want to be loaded/executed on example page. E.g &lt;link href="../template/theme/css/sdk-inline.css" rel="stylesheet" /&gt;. < and > characters have to be encoded.


In content might appear macros which will be replaced during samples building.

Macro Description
{%CKEDITOR_VERSION%} CKEditor version used to build current samples, e.g. 4.11.1
{%CKEDITOR_EXAMPLES_SLUG%} Examples slug, path where are stored all examples in build docuemntation. E.g examples


Umberto provides possibility to use customizable macros in documentation. Those values will be replace during documentation generation. To use this feature you need to define variables object in umberto.json and/or umberto-main.json. Variables provide in umberto-main.json takes precedence.


Variables have to be written in capital letters (also allowed characters are numbers and underscore). In text variables have to be used as macros surounded with {% and %} strings.


  • umberto.json

     	"variables": {
     		"VAR_1": "first",
     		"VAR_2": "second"
  • umberto-main.json

     	"variables": {
     		"VAR_2": "Foo bar baz"

  • output html

     Foo bar baz

Releasing package


Before starting the release process, you need to generate the changelog:

npm run changelog


After generating the changelog, you are able to release the package.

First, you need to bump the version:

npm run release:prepare-packages

After bumping the version, you can publish the changes:

npm run release:publish-packages




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